Z28 Boy

i did a search, but couldnt find anything that matched this...

it's pretty simple. when the car is cold (when i say "cold", all i mean is that it isn't at like operating temperature...like if it has been sitting for a while), it turns over for like almost a minute before it starts, but they starts right up.

but, when it's warmed up, it will start right up, no problem at all.

anyone have any ideas what could be the deal? it hasn't always done this...it probably started towards the end of last summer. i havent checked to see if there is fuel pressure as it is turning over and over when it's cold, but i am assuming that there is. what i mean, is that i dont think its the fuel pump.

what could be the problem?

thanks...

-brian

brharris27370

Have you had someone cranking it while you watched to see if the injectors are spraying any fuel for that long crank time.

It could be that a bad pressure regulator diaphram is allowing all the gas to drain back to the tank and the pump has to pump the lines full of gas again. But that is just a guess. Never actual heard of anyone having that problem.

A clogged fuel filter could slow the systems priming down so that it takes longer to get the system up to pressure.

Just thought I would throw those ideas out there.

RBob

iTrader: (1)

In a quiet area (ie: turn radio off), turn the ignition key to the ON posiiton and listen for the fuel pump. It should run for two seconds before stopping. If not then the fuel pump relay is most likely bad.

Another possibility is a weak spark. If coil is going then will need a lot of fuel before it'll fire off.

RBob.

91Bird305

***, that peice of **** acting up again? Man I tell ya what, u need to sell that to me. I will take 3,000 for that peice.

My car used to do that but it went away when I did this.
Bumped my timing to 6 degrees.
Fuel pressure at 12psi
MSD Cap/Rotor
MSD 8.5mm Superconducter
AC Delco plugs
Fuel Filter
New Battery

Now even after sitting for weeks in storage it will start right up.

Darth Cypher

I have a similar problem here in the UK. My car ('89 RS) would never start on the first attempt but on the second it would start. I would have looked into it however I was in an exercise and 13+ hour shifts doesn't give me much time to work with.

Halfway into the exercise it simply died when I was about to drive home. I tried multiple times and it wouldn't start at all. It is getting fuel. I smell it when I pop the hood and there are no leaks. So it sits until the exercise is over and me and a co-worker go to take a look. Popped off the distributor cap and it was pretty corroded and the rotor was pretty shot. It would work but it was a good idea to change it.

Some of the corrosion was cleaned off and it and was put back together. Attempted to start it up. After giving it some gas it started up.....reluctantly. So I ordered a new cap and rotor followed by some MSD wires.

Took about a week and a half for the cap and rotor to get here. Swapped them out and the car started like a champ. Drive it for about four days and then it won't start on the first attempt. Second it ran fine. Great. I went to the auto store on the base and got some spark plugs (still waiting for my wires from Summit). My driveway sucked so I couldn't use the jacks and stands on it and was going to park it on the curb partially to give me sufficient leverage. Wouldn't you know it, it died again. Same problem.

Found a shop in the next village that does work on GM and Ford cars and is certified to do warranty work and so on. Wish I would have known that then I would have shipped the '01 Z28 over. So I am going to have to bite the bullet and have them look at it.

It's wierd that it ran good for a few days and then did the same thing. I wonder if I'm running rich or something or if it gets flooded after a while or what. Well, I'll let you all know how it turns out but if there are any suggestions I'm listening. Thanks.

Mike1

iTrader: (2)

Mine doe this also, when it's real cold out I gotta try several times to get it to start, even gotta give it alotta gas to get it to fire. When it does it sputter really bad before it starts to idle smoothly. When warm will start fine. Has had a recent tune up. Very strange.

iroczrockz

You guys aren't running Champion spark plugs are you? Don't know why but I had a similar problem after I put in some Champion plugs. I changed them out and put in some good ole fashion AC Delco plugs and the krap went away.

Darth Cypher

Don't know what plugs are in my car as I recently bought it. It very could have the original plugs in it as it only has 76,000 miles on it and since it is an '89 it has obviously been garaged for periods of time.

firebirdpl

sounds like its time for a good tune up, plug wires cap rotor etc

Darth Cypher

Ok, my car is still at the shop but I called to get updated on what they are doing. They did a tune up, the spark plugs were fine, they cleaned them up and regapped them.

They said that they found that the ignition timing was off four degrees. Forgot to ask if it was advanced or retarded by four degrees. Anyhow, they still wanted to keep it for a while to see if it will start up fine or start to give them problems like it did me.

Anyhow, does anyone think that the ignition timing could cause the problem I have been having? I ask people and it gets mixed views on it.

tanager11

"Cleaned and re-gapped your old plugs"???

I would say given the amount of effort to pull/"clean" and re-gap the plugs you might as well replace them. If they are charging you for this tell them to take a hike.....they should have just replaced them, the $20 bucks for them will be well worth it.

Darth Cypher

Yeah, I know. I told them to do a tune up wether it was the cause or not. I was in the process of doing the tune up when the car died and I decided to take it to the shop when it decided to run again. Saved me from paying to have it towed.

I have a set of MSD wires that just shipped out so I will be doing that when I get my car again. I just didn't want the car to run for a while, die for a while, lather, rinse and repeat. It's kind of annoying to keep getting rides from work (I don't like to inconvenience other people) so I wanted to have it troubleshot in case it is something that is beyond my very limited knowledge. And I have no idea (much less a timing light) to tell if the timing is off and to fix it.

tanager11

...as for the timing....I suggest grabbing yourself a Hanes or chiltons manual, open it to the page where they go into setting/checking timing and just try it out. Dude, its the only way you are going to learn.....I always say its a car man if you screw something up (which you wont with checking your timing) you can always pay someone to fix it.

Darth Cypher

Already got the Chilton's. I don't have the tools though and I can't get the tools without a car.

Ancel Zero

Geeze! I am having the same frickin' problem. The car takes forever to start when it's cold and then when it does start it sputters for a whlie then it runs good. When it is warm it dosent have any trouble. I've already replaced the wires cap rotor plugs and even the fuel pump. Still dosent want to start cold. When I get more money I will take it someone and tell them to fix it! and put me a new engine in there too!

Ancel Zero

Oh, BTW, my car is a 350TPI though.

Darth Cypher

Ok, car died again but when it did I tried to start it with the gas pedal all the way down as some people have told me about after my car was in the shop. Well, it started without any problems. Next two days when I made the first engine start of the day it started up fine. I don't get it but oh well. If the gas pedal trick works then I'll take it unless something else is wrong.

Note: When I made those two engine starts it was without doing the gas pedal trick. It started up completely normal.

iroczrockz

You think maybe your throttle is sticking shut when it is cold? Don't know how tpi works but sounds like maybe it isn't getting gas or air.

Darth Cypher

Well it is getting gas because when this first happened and I popped the hood, I did smell gas (no leaks). If it is getting enough however is beyond me.

iroczrockz

That makes sense if it isn't getting enough air. Does tpi have a butterfly in the throttlebody?

Darth Cypher

I think so. Besides, my engine is a TBI.

iroczrockz

Oh ok sorry I thought it was tpi. Well do you think your butterflies are getting stuck closed? Have you tried spraying carb cleaner in there?

Darth Cypher

No but I'll remember it in case it is a problem or contributing factor.

iroczrockz

Hey didn't you say you tried putting the pedal to the floor and starting it? I wonder if you tried putting it to the floor then letting off of it then try starting it, if that would do the same thing?

Darth Cypher

Someone at work said something about doing that in the cold weather. I haven't tried it though but I'll remember the next time it dies when I try to start it.

firebirdpl

try pumping the pedal a few timnes when cold may help in extreeme cold dos on my car when it is below 20

Darth Cypher

Cool, well anyhow, I feel a lot better knowing that I can get my car to start at least. Sounds like there was no problem in the first place other than my ignorance on these engines (always had the "new stuff"). Well, anyhow, thanks for the feedback.

84Z28_5.7ltr_V8

try putting in a manual choke? i have to use mine all the time when i havent driven it for a while.

NJ SPEEDER

TBI uses a IAC stepper motor to regulate air on start up, not a choke.


later
tim

84Z28_5.7ltr_V8

i see