Abubaca

iTrader: (3)

Guys I'm stumped. Every few months my car won't start. It's never first thing in the morning, rather once I've been driving for at least a few miles. It'll crank and crank and crank. I'm getting fuel pressure, and I know the plugs are firing. Can't be sure the injectors are firing. Anyhow, after about an hour or so, it'll start. No rhyme or reason that I can figure. Today it wouldn't start at the gas station. I got a ride home to get tools and tinker, when I got back, vroom! It started right up like nothing had happened.

Twice (it's done this 4 times now) I was able to take the wires and cap off, reconnect it all and that did it, but I can't be sure removing the cap and wires is actually what made the difference.

I have NO idea. Maybe the distributor???

Abubaca

iTrader: (3)

Ignition module has been replaced BTW. Cap, plugs, wires, coil, rotor....all have been replaced and yet it wouldn't start today.

What about the computer? I really don't know the inner workings of the distributor, could that be doing it?

Vader

Have you closely checked the distributor primary connections? Pickup coil and connections? When it doesn't start, are you CERTAIN it is getting spark? Have a 'noid test liight?

Abubaca

iTrader: (3)

Connections all seem to be ok. As for the plugs firing, I don't know if this is a backwoods po-dunk method or not, but we pulled the wires off the plugs and checked for the arcing charge. Sure enough, about 5 of them all fired. We didn't keep checking because we only had so much battery and we didn't want to keep cranking it.

I'm totally stumped. If it did it more often, but would start after a few attempts, I could see it maybe being a bad connection. This will be fine for months, and then out of the blue, NOTHING. Then after an hour or so, after we're all sitting around scratching our heads NOT messing with anything, vroom! She'll start like it never had a problem. A few of my friends have been around for a few of these episodes and they all agree that the way it'll just start up out of the blue is weird.

Vader, I've learned that you know a heck of a lot more than me. Any more help is greatly appreciated.

Vader

Just a WAG, but is the distributor cap and interior of the distributor clean, and DRY? A little moisture in the distributor can do just what you describe once the engine warms and evaporates the moisture. The fact that you are getting spark at 5 plugs is a bit of a hint.

Vader

I doubt that I know any more, but I might know a few different things. Everyone has different experiences and educations, and some just have more miles on them.

Trickster

Hello Abubaca,
Just to chime in here a little bit, I noticed that you have an 89 Iroc. Does your security light come on during the times that you have had this problem. Also have you checked your Park/Neutral switch lately?

Vader

I thought about VATS, but it is presumably cranking, since there is a way to check for spark. Am I mistaken/confused, or does the '89 have a start enable relay?

Abubaca

iTrader: (3)

My understanding is that VATS won't let you crank it at all. My car will crank till the cows come home!

Neutral safety switch, hmmm. I'm still thinking the car wouldn't crank, which it does.

Vader, I'm thinking that the spark at the plug would eliminate the moisture in the cap possibilty. Is that correct? Just to clarify, when I said that 5 plugs fires, that didn't mean 3 didn't fire. We saw the first 5 arcing and figured that wasn't the issue and decided to save the battery and not test the other 3. I know, never assume, right?! It was late, we were tired and frustrated and said screw it!

could the computer somehow be messing with the timing?

Abubaca

iTrader: (3)

This may be a dumb question, but can the TPI flood like a carb?

Trickster

Vader, you aren't mistaken or confused unless you are thinking the 89 Iroc doesn't have a Starter Enable Relay. It does and it is located behind the left kick panel down where the door power lock relay is on some older models.
Abubaca, in some instances the VATS can malfunction and still allow the car to crank but not start. CHeck your e-mail, I just sent you the VATS schematics. Another thing that you might look at is the ground for the ignition coil. It can cause intermittent hard starts.

87Formula4bbl

I'm having an intermittent start problem just like this. This should be an easy question, is the coil itself supposed to be grounded (the 'frame' or structure that it is mounted in that bolts to the intake)? I have mine mounted to my valve cover and I'm wondering if it's not getting a good ground there, I didn't think to check it when I was home though.

Sorry to hijack.

dyeager535

After having to wait over a year to work on the problem, update here so no one needs to read MY portion any further, other than to understand what was going on.

Went and got a new to me ECM. Replaced, problem gone. Got my new Ford injectors installed, sold my old stock ones, buyer had them tested, 3 of the 8 were "dead". Decided to install my "dead" ECM, and see what happened. Sure enough, problem no longer occurred. Go figure. Problem solved, bad injectors!

Here's my similar problem intermittent crank no start

Haven't dealt with it yet, other vehicle issues more pressing so far, but I did test the injectors since it's easy, and there are a few that are not "synched up" close to the others. (one way way off, two that are read a few ohms less than the others, might be standard deviation)

I'm going to replace my injectors based on the one injector anyway, but if it happens again before or after, I'm going to be making sure that my test tools are in the vehicle.

But as you can see from the responses to my post, the causes can be quite varied, and just need to be tested the moment the problem is occurring.

Be sure to post up your progress or even lack thereof. I'm definitely interested in seeing this one followed through.

Abubaca

iTrader: (3)

That's an interesting thread. Sounds like it's the same problem, and you and I are NOT the only people who've had it. The tricky part is that it does it so rarely that it's tough to work the problem. When it DOES happen, I'm never in a place with the tools to do it.

I'm still running the OE distributor and injectors, so that's certainly a possibility for problems. Of course, ALL the wiring is original too.

I know I'm getting spark, and I know I'm getting fuel pressure to the rails, but I'm not sure if the injectors are firing. How would I test for that?

Dan8289gta

You need to get a noid light to see if the injectors fire, I had a similar problem where i had 3 injectors going bad and it eventually toasted the computer creating a crank but no start scenario.

dyeager535

I made a noid light just for this purpose. I just took two wires, stripped a little insulation off of both ends, and took a 194 lightbulb (for dash) I had lying around. Straightened the wires out that are on/in/through the bulb, then just attached one wire to each bulb "lead". Then you just take an injector connector, pop it off, stick one wire into each connector terminal, and crank the engine.

I guess you should be careful to make sure the two wires don't touch, but you can solder a piece of paperclip to each end to make a "stiff" piece you can plug into the connector if you are worried about it.

MasterEvilAce

Question.. Does the car STALL, and then won't start, or is it when you shut the car down, it won't start, again?

My '87 IROC-Z 350TPI did this a few times... but with a hugeee length of time inbetween... It would stall and then I'd go to start it again, and it would crank but not fire. I would try every so often and eventually it would start right up, and run fine.. Very weird problem. The fuelpump WAS a problem, but the new one was a few months old (and had run fine prior to the incident).. so I ruled that out..

dyeager535

In my case it ws once you shut it down. Running perfectly, shut it down, (such as to go into a store) come back, won't start.

Abubaca

iTrader: (3)

Me too.

No stalling, just restarting. It always seems to do it after recently being shut down. Twice it's done it after being at shows and starting it so people could listen to the exhaust. Last time (this weekend) it did it after filling up at the pump.

...but don't get me wrong, I'll start it up quite often for people to hear it and then shut it right back down. Two weeks ago at Lowes Motor Speedway our club was doing a shoot in the infield and it musta been started and stopped 8 times within an hour.

Lucid

iTrader: (4)

I had this problem happen once, and its very frustrating to find the problem. Have you pulled the plugs to see what condition they are in? The last set of Bosch platinums i had were covered in deposits, some in between the electrodes but amazingly the car ran.
One time i had a no start condition where the engine would crank and wouldn't start and i replaced the MAF sensor and it ran just fine. Of course i ran the trouble codes and made sure that i was looking in the right direction. A couple years ago it happened again, i replaced the cap and rotor and oxygen sensor, spark plugs and etc and it ended up being the fuel pump relay or a bad MAF sensor relay. Mine are located on the fenderwell on the drivers side. The ECM has a clear flood program. Hopefully you do not have water in the tank and you have been changing your fuel filter regularly. Do you have access to a scanner? Also I had an alarm go out gradually with the kill switch, and for some reason it would cause a delayed start. I ripped that thing out and replaced it. Have you checked the timing on it? Ground the diagnostic terminal and check the base timing on the number 1 Cylinder. If the plugs are firing way to early or way to late on the exhaust stroke its going to run funny.

z28freak84

having the same problem with my 89 formula 350. Used to happen sometimes, Now its EVERYTIME. I spray some brake & parts cleaner in the TB, and it fires right up and runs fine. Shut it off, and it doesnt even THINK about starting. Wait an hour or so and it fires like its about to start, and then it doesnt. Spray some more brake clean in the Throttle Body and it will fire right up.

Its definately fuel related.
my car sat for years. I am going to change the fuel filter to eliminate that, but I think its the injectors or the computer.

dyeager535

"Have you pulled the plugs to see what condition they are in? The last set of Bosch platinums i had were covered in deposits, some in between the electrodes but amazingly the car ran. "

In my case yes, the engine is brand new, AC Delco plugs, all in very good shape.

"One time i had a no start condition where the engine would crank and wouldn't start and i replaced the MAF sensor and it ran just fine."

"new to me" MAF that replaced the old one due to Code 33. Shouldn't be an issue, it responds correctly when scanned.

"A couple years ago it happened again, i replaced the cap and rotor and oxygen sensor, spark plugs"

All new/good when engine was rebuilt less than 2K ago.

"ended up being the fuel pump relay or a bad MAF sensor relay."

Since MAF works, no codes, and the fuel pump primes as it should, I don't feel it's any of those.

"Hopefully you do not have water in the tank and you have been changing your fuel filter regularly."

Tank and filter new when engine was rebuilt, sender is new, pump and sock are new. Tank was kept full all the time, so I really don't suspect water contamination to be a culprit. Of course I understand that new never=works right, but when the problem happens, it's random/uncommon, not consistent like you'd expect from one of these causes.

"Do you have access to a scanner?"

I think neither of us have/had the right tools with us for diagnosis at the time. A noid light for injectors and the scanner would be nice, but when I came back with tools, the first thing I did was scan the ECM, and no codes. Of course, after scanning and finding nothing "unusual" (CTS, TPS all ok, etc) it started, so no conclusions can be drawn from those findings.

"Also I had an alarm go out gradually with the kill switch, and for some reason it would cause a delayed start. I ripped that thing out and replaced it."

I built this vehicle from the ground up about 5 years ago, and installed a factory harness I pulled and inspected. There is nothing tampered with in the wiring system from stock.

"Have you checked the timing on it? Ground the diagnostic terminal and check the base timing on the number 1 Cylinder. If the plugs are firing way to early or way to late on the exhaust stroke its going to run funny."

It just doesn't start. It runs and idles excellent 100% of the time, that is when it starts, which is about 99.5% of the time.

The only things (likely culprits IMO anyways) not "new" or confirmed good in my setup (I installed it all) are the distributor components, short of the cap/rotor which are new. As in my other post, the injectors are also used, and one of them is quite a ways out of spec. That had been a culprit for another member here, and since they need replaced in my case due to the way a few tested, that will happen regardless. Personally I suspect the module, but going to have to wait and see if I'm getting an injector pulse when it's cranking and not starting.

It's not road-worthy right now (various mods in progress due to blown up rear axle) but when it is, a noid light for sure is going in the vehicle. I'm not replacing ANYTHING until I know exactly what causes my problem. It's intermittent enough that throwing parts at it won't prove anything...I don't want to have the problem crop up after I'm confident I fixed the problem.

irocdaddy

Add me to this list of mystery no starts. Has happened for oooooh, 10 years? Like abubaca, my car runs great, plugs etc. look great, I first thought of the ign. module getting heat sink. If I remember though, starter fluid in the tb got it started. Of course, it would help us if there was a second person doing the testing while the other cranks the starter. When mine does restart, it seems like the fuel pump is acting weak, but I have correct pressure at the rail during no start cond.

bk41042

Have a 1988 T/A GTA 350 TPI that cranks and starts fine cold, runs, drives fine. When shut off cranks fine but won' start, have spark at plug wires, have tried starting fluid but didn't help. It looks like this thread addresses that but no definite cure. Looking for some help. Thanks

Lucid

iTrader: (4)

I know how you guys feel. My car sat there for at least a month one time while i tried to figure out what the problem was. It would crank and crank and crank and sometimes run and then shut off by itself. After going through all the standard tests and replacing this item and that item, i noticed that the SES light was blinking/ flickering at a very fast pace when the engine was on, almost imperceptively. Not the standard blink...pause....blink when its in diagnostic mode, but like a tv with a bad tube. I was at the end of my rope and bought a new computer, after i determined my ECM had a bad quad driver. The mechanic that rebuilt my engine jury rigged the fan relay to run constantly as long as there was key power and apparently it had overvoltaged the ECM (at least thats what i think it was because that wire was in that quad driver). Also waaaaay back in the day we had a fuel pump go bad, the dealer had a fun time figuring that one out. My car is doing the long crank time right now, and i hope its just time to change the plugs....my MAF was working when the relay was sticking, it just had an extended start, and it was really intermittent. Also in the TPI cars i believe that the oil pressure sender is tied into the fuel pump relay, i dont know if that is pertinent, but if the relay dies then the pump gets energized due to oil pressure. If the fuel pump relay clicks it is probably ok though. Let me know what you guys find

Dan8289gta

If the oil pressure sending unit goes bad it will blow a fuse by your battery that is connected to the fuel pump, you wont get the ses light with the key forward if that happens.

Abubaca

iTrader: (3)

Lucid, it sounds like you have a different problem than "we" do. I've never had a shutting off problem, or and SES light. I only have problems re-starting, and it's rare. Maybe every few months.

I'd be more than happy to never figure it out and never have it happen again!

rgarcia63

My 88' is an IROC, so I don't know if this goes for an 89' if it has a different engine package:
The oil sending unit is next to the distributor, and isn't powered by the fuse near the battery.
The oil pressure switch is located near the oil filter, and it is powered by the fuse near the battery.

The oil pressure switch is either open, closed, or fails to close, or open, none of these conditions will cause the fuse to blow. If it's possible for the switch to make contact with it's body which is grounded to the block, then it would blow the fuse, but i don't see how that could happen.

Lucid

iTrader: (4)

Just trying to help in anyway i can, i can only tell what my experiences were with my car. When the oil pressure sender went bad by the distributor it did not blow a fuse, and then it did the nice thing and started spraying oil all over the ground. Also i had an intermittent problem with the TPS sensor recently, when i scanned it it would blip fine and then suddenly blip zero or close to it. I changed out the connecter and the TPS and ran continuity from the computer, which was fine, eventually i traced the wire and found this little tiny place where it had rubbed against the frame and was grounding itself.....intermittently. Just keep poking around until you get it. Good luck!

Alexcoqui

My first car was an 89 Bonneville & it gave me the same problem for years. It didnt want to start when the engine was hot, like when you stoped at a store for a few minutes. But it wouldnt do it all of the time only every once in a while. (Allways at the worst moment.) I lerned that I could start it with a screwdriver at the starter. After a bunch of mechanics faulty attempts to fix the problem I found a mechanic that told me this was a normal problem in some GM cars. It was a long time ago & I was a kid so Im not a 100% shure but I remember it was something about the cables that come out of the battery to the starter, they are not thick or strong enough to hold the current & they would heat up to mush or something lilke that. Story short he changed cables & it never happened again. Not shure if this will help or not, maby not eaven related but it sure sound familiar.

rgarcia63

That's why heat shields were added, but even then it still happens.

The following link has a fix similar to what I used for 20 years on my 84' Fiero, and my 88' IROCZ when it started doing it. The ignition, auto nuetral/park, and manual safety switches cannot handle the current when the starter solenoid pull-in, and hold windings get too hot.

This design works because it remove the solenoid away from a high heat area, and because the ignition circuit energizes a low current device.

There's talk about integrating the alternator & starter, with coolant flowing around it.

Hot Start Cure and Remote Starter Switch

IROC212

iTrader: (1)

My sister's camaro had a similar problem. It was extremely intermittent, and even though it was making spark, when I touched a plug wire to ground, it must have been weak. I replaced, tested everything but the pickup plate. I read in the chiltons to check resistance in different places. I found the plate was shorted to ground sometimes. I replaced the Dist. (didn't want to mess with re-phasing the rotor) car works perfect. I hope it helps.

sr.bond

i had the exact same problem with one of my babies.only that this happened on a carbureted non cc. car .it ended up being the distributor. i replaced it,problem gone forever

azvolfan

This sounds like the same thing that happens to me every few months. And I think I know what it is.

Will your car stay started if you have your food on the gas pedal? Mine does. I can even drive it as long as I drive two-footed. I just have to always keep slight pressure on the gas even when I'm braking. I think it is the IAC valve. Infact I just pulled my plenum and the IAC valve is rather encrusted with carbon.

azvolfan

Here is another pic.

Will carb cleaner clean this off?

Abubaca

iTrader: (3)

It's not heat soak. The starter turns over like a champ!

Lucid

iTrader: (4)

azvolfan,
Yeah looks like you need to clean your IAC valve there, get some intake cleaner, and buy some new gaskets for your throttle body. This is a TPI right? Remove the tranny cable and throttle cable, disconnect the tps and then remove the bolts holding the throttle body to the plenum and carefully remove the vacuum line and clear off the old TB gasket. Then spray that intake cleaner on the throttle plates and get all that gunk off, and clean your IAC valve as well, especially the pintle (the head) dont get any on the electrical components. Make sure you get that intake cleaner in the IAC passage (you can even remove the cover for it but you need a new gasket). Reinstall the IAC Valve with a new gasket, and line up a new throttle body gasket on the screws that hold it onto the plenum. Heres a picture of how clean your throttle plates should look:

88IROCZZ4

a buddy of mine had the same problem. it would only happen after he'd been driving the car and it was hot. discovered that the starter was heating up too much from his headers ... he swapped his starter with a smaller gear reduced one and put a heat shield on it. has never had the problem again ... been a couple years since. good luck to ya!

rgarcia63

That's not the type of no start he's experiencing

Abubaca

iTrader: (3)

OK, here's some more food for thought:

The other day I filled up with gas and the car wouldn't start for about 3 or 4 seconds of cranking. Normally she'll start up with no more than 1 full second of cranking if not right away.

That got me to thinking about all the other occurances. It's always after it's been recently shut off, OR after it was run for a short amount of time. For example, starting it up at a cruise in for people to hear, then shutting it down after a minute.

We're thinking heat, but could it be something to due with the fuel system? Priming? Pressure? I have pressure during these problems, but I can NOT say what pressure.

rgarcia63

Since it's a once in a blue moon occurance, I suggest connecting a fuel pressure gauge full time, the other thing to do is get a sample waveform of the fuel pump signal, and compare it to when it acts up.

FYI, but you probably aleady know this.
The fuel pump is in the tank to eliminate vapor lock due to heat.

azvolfan

How old is your fuel pump. Sometimes a fuel pump on it's last legs will quit after it gets hot. That happened to me a while back. It is also how I got my stolen car back. The idiots stole it from in front of my mechanics shop after I dropped it off. They got about 10 miles before the fuel pump quit.

But before it quit for good is was giving me a hard time starting every now and then.

formula1988

I Have the same exact problem. It happened to me today. I had to wait 30 mins before it would start. I took it in today because of an oil pressure sensor and the guy there said my started is going bad. So i'm plan on getting a new starter and seeing what happens. I'm going to print everyones post on this topic and let my brother look at it and ill see what he says.

dyeager535

Starter isn't the cause if the engine will turn over. In our cases the engine turns over, so it's not the starter.

Abubaca

iTrader: (3)

OK, more questions. Bad news is that the problem is getting more frequent, although it DOES making trouble shooting easier.

To bring everyone up to speed, here's my smptoms: Every few months, now every few days, the car won't start. It has NEVER done it cold. It normally does this when hot, but it has done it after a few hours before, while the car was still pretty warm. it (so far) has started after about 30 minutes to an hour after the initial "no start" every time.

This afternoon, It started, ran for 5 minutes, then I shut it off. It barely started back up a few minutes later, then I shut it off. It would not start again after several tries. I went inside for an hour an came back out and it fired immediately.

When it's NOT starting, it'll crank for days, with not even a hiccup. It's like there's NO fuel or spark whatsoever. New coil,cap,rotor,wires,plugs,module. I had the problem before I upgraded to the MSD 6A, and I still have it. Bypassing back to stock has no effect.

When it did this today, I confirmed that I have a solid 40psi of fuel pressure. So it's not the reg. or the pump. I have a noid light on order.

Questions:

During this latest no start, I had 40 psi at the rail. Can I eliminate the fuel pump, at least for this problem?

If even ONE injector fired, would I at least hear it trying to fire? Right now it doesn't sound like there's ANY ignition at all.

Can I hook up a timing light, leave the computer connected and see when the computer is firing the plugs? Instead of changing the timing, I'd be just watching where it's currently timed.

...anyhow, I'm gonna work this thing 'til I get it. I'll keep you all informed. It's now done this twice in two days, so I really have no choice.

dyeager535

I'm still following this one!

All I've got are these for you:

crank no run 1

crank no run 2

Hope those links work. A little small, but big enough for me to read.

That scanner one for engine RPM (first test block) doesn't work in my case, the scanner doesn't appear to register the cranking RPM, even though it cranks and starts (most of the time) so I'm not sure how helpful that one is. If I'm not mistaken, that's making sure the ECM is seeing the engine turning over, but for what reason...? That will send you down a totally different path in the troubleshooting.

I need to play around with my autoxray more to see if I can get it to read engine RPM when it's cranking, just so what is happening to us can be tested per the flowchart when it occurs.

Abubaca

iTrader: (3)

I can read 'em, but I'm quite there yet. I'm gonna confirm pressure, spark, and injector pulse to each cylinder first. We'll go from there.

...check back soon

Lucid

iTrader: (4)

If you have a stethoscope or if you press your finger on the injector plug you can feel/hear it clicking when it is firing. This is where the noid light will come in handy. If its not clicking then you need to get your hands on Schematics of the the ECM wiring, in particular the injector/fuel pump wiring.


Before you turn the key next time, turn off the radio and the heater/ac controls. Turn the key with the door open and you should hear a click when the fuel pump relay kicks on and the fuel pump should whine for about 3 seconds (its priming).

AFTER the no start and the engine does start, does the engine sound funny when it starts? Is there funny colored smoke coming out of the tail pipe? Are you starting it with the key only, or is your foot mashed to the floor?

Dan8289gta

My last crank no start situation was due to 3 bad injectors 1 was so bad if it was plugged in the car would not fire, If you unplugged it the car would fire and run on the other 7. Check the resistance on you injectors they should be 16 ohms or higher, anything under 10 is toast.

Abubaca

iTrader: (3)

OK, no start once again tonight.

I had spark.
I had pressure to the rail. (40psi)
I had an injector pulse.

The light/pulse was pretty dim until the car actually fired and then it got pretty bright. I'm guessing this is normal, and due the the draw from the starter. I shut the car off, and of course, it wouldn't start agian.

I plan to have the injectors all cleaned and balanced since it's about time (170,000), but I honestly don't think that they're the problem.

I just don't know what to do. I know troubleshooting is part of the hobby, but I'm simply at the end of my knowledge here. I don't mind buying parts, but just about everything is new, and other people seem to have similar experiences. Problem before new parts, problem after new parts.



Coould it be a TPI sensor? I'm just throwing out thoughts. If it were a computer/relay issue, first, where do I start, and second, would it be at starting only? As with others, it'll run strong all day long, just won't always start.