82knightrider

iTrader: (1)

I went to turn my car on and I heard the fuel pump prime,but when I turned on the car stayed on for like 1 minute and then died.
So I turn the key off and back on and now I dont here my fuel pump priming.So I turned it off and waited like 5 minutes and then I turn the ignition back on and now I here my fuel pump for a few seconds then the sound dies out.......
Do I have a bad fuel pump?

82knightrider

iTrader: (1)

Before I change my pump I want to replace relays and fuses.How many relay(s) and fuse(s) operate this fuel pump and where are they located.?
Im gonna replace my opsu for the hell of it too.

82knightrider

iTrader: (1)

bump

da BEAST

I am in the same boat as you. I cannot get my fuel pump to fire. I thought I replaced it over a year ago but not too sure...This is a project car and I haven't been working on it lately. But now i really need to get the ball rolling. How do you test the fuel pump relay, fuseable links and the fuel pump it self? I also would like to know if there is an easier way to get to the fuel pump besides dropping the tank. I did a search on it but no answers.

82knightrider

iTrader: (1)

The only way to get to the fuel pump w/o a hack job is to lower the tank.

DF'sCamaro

I think that I may have the same problem a dead or dieing fuel pump. My car lately had been running rough and ever so often dieing when running at idle like in the driveway(for like 4min or longer). So now it wont start and it all happen when I was going to pull out onto a major intersection right before waiting for traffic to clear idling it died. So I went to try to start it back up and it wont, makes a fuel/bad egg smell after cranking on the starter. I can also hear my fuel pump prime, just wondering why it just died and why it won’t run. Any ideas on where to start or if my fuel pump dead? Need to get it fixed for its a daily driver.

sqzbox

To test your fuel pump, apply 12v to the G terminal (lower left corner) on your ALDL connection port under the dash. If your pump is good, it should run. When you turn the key on your pump will prime and then shut down when it reaches the correct pressure. After you turn the key off, it will take a few sec. for the pressure to bleed off before it will run again when you turn the key back on.
If your pump is going bad you should get a code 54.
you should have a fuse in the fuse block, a fuel pump relay mounted in a bracket on the firewall next to the brake booster, and a fuel pump switch mounted just above the oil filter. The switch only comes into play when the relay goes bad.It see's oil pressure and tells the computer that the engine is trying to start and activates the fuel pump.

da BEAST

sqzbox those are very good instructions.But please give our slower people that rides the short bus how to do what you decribed in a 101 course. i.e ALDL connection port location and where to hook up. I also have an OBDI but I do not get any codes except an O2 sensor problem, but thats another Jerry Springer show. Pics would be a plus. I Know I might be asking alot.. but hey you got to start from somwhere.

Thanks da BEAST

82knightrider

iTrader: (1)

sqzbox

Hope this helps! My resorces are limited and I've never attached on this site before. I rode the long bus, so eventually, I'm going to learn!

sqzbox

wow! that's really big! He won't need no glasses!!!

astrosteve

Mmmm ive just read this thread and its striking alot of bells in my brain!
I too have a fueling problem, so im goiong to watch this thread with interest.
It was interesting to read that the pump when pressurised shuts down, but surely isnt that what the fuel return pipes are for?
As for the oil pressure switch, is it in the same location for a V6?
Imhaving trouble tracking it down.

astrosteve

Oh and by the way i did start a similar thread in Dec,

if anyones remotely interested........???..... no?

82knightrider

iTrader: (1)

So I run A wire from my battery to the connection you mentioned in the ALDL?What gauge?

da BEAST

Thanks sqzbox. That was very good info. Love to see others willing to help the Thirdgen community. I did as you explained and narrowed it down to my fuel pump. Dropped tank(that was a job) and now I am trying to figure how to get the pump off without tearing up the retaining ring. Any Suggestions?

82knightrider

iTrader: (1)

Wow your making some good progress beast.Ive just barely narrowed it down.Im gonna start taking the tank out tomorrow

Steve86TA

iTrader: (57)

Make sure you check the fuse near the battery BEFORE you pull the tank out.

da BEAST

My pump was defintely the problem. Question.... Which is the fuel pump relay. I found the fuel pump relay mounted in a bracket on the firewall next to the brake booster but I has an identical relay next to it. I think its the A?C relay. So facing the car which side is it, the left or right?

82knightrider good luck with the tank. You are going to need it. Some little advice, if you have a lift that will be great. But like most of us we are not as fortunate so I suggest four jackstands to make sure car is high enough. Unbolt the exhaust at the cat . Remove muffler. Remove two bolts holding the panhard bar in place; remove bar. Remove gas door & plastic funnel. Remove two bolts holding tank in place. Remove hose clamps & flare fittings on fuel lines. And wiggle, jiggle,shake your azz off. You may need help but I did it alone. Wish I had help. Once you get tank off make sure you use a round chisel and not a flat(cutting) chisel to knock off the retaining ring. Spin it counterclockwise and boom you got it.
Put it back to together and gather up all the spare parts that you can't figure where the heck they go and drink some beer.

da BEAST

sqzbox

The relay switch will be the one with 5 wires. org, blk&wht, red, gray, and grn & wht. Orange should be hot, it goes to the inline fuse. Red goes to the pump and blk&wht is the ground. If you can get someone to turn the key on while your under the hood, you can hear the relay click and feel it with a finger on top of it.

DF'sCamaro

OK my pump was not the problem I getting fuel but it still won’t start. I’ve checked for spark (not getting any) and even replaced my old ignition coil. The ignition coil reads like 1.5volts or less with a multi-meter and we checked all the plugs. Is it possible that I fried part/all of my ecu, even though everything else works like fuel primes and starter cranks?

sqzbox

Only thing left other than the ECM is the ignition module in the dist. and the control module next to the vacuum brake booster. It's about 4in by 5 in square box about a half in thick mounted in the same area as the fuel pump relay and AC relay.

v8unleashed

iTrader: (3)

Has anyone suggested just WATCHING the fuel AT the carb/TBI to see if it stops flowing right before the car dies???

Seems to me that's the easiest way to figure out if your pump is stopping and the car is dying because of it.

DarkKnight33

I am having a very similar problem right now. However, it's wierd because the car will start fine when it's hot. Anyway, I got a fuel pressure gauge and have it hooked to the schreader valve on the fuel rail. When I turn the key on after leaving the car overnight, the fuel pump will come on and prime as expected. The gauge reads something like 42 PSI. I attempt to start the car, and it starts the fuel pressure bleeds off then the car immediatly dies. I put 12v to the G Terminal on the ALDL connector, and I use a remote start switch to either apply the +12v or not. When I pull the trigger, I hear the relay click. I thought the G terminal went direct to the fuel pump?

Anyway, even when I put 12V to the G terminal, the fuel doesn't always come on. If I pull and release the trigger rapidly for a min, eventually the pump will come back on, and as long as I hold the trigger, then start the car, the pump continues to work, and will work while the car is hot. Once the car cools off again (and it's cold as hell out here) the problems start up again.

Any ideas?

sqzbox

First, I think your fuel pump is on the way out. Most fuel pumps on 3rd gen's don't just quit all at once, they go bad over a period of time untill they just can't provide enough pressure anymore to supply the injector's with enough to run the engine.
For example, when you first turn the key on, your pump will prime the system with 34-47 lbs even if it's going bad but it will take longer to prime than it would if it's good. Then, after it starts, if it can't maintain the pressure while it's running then you start having problems.
You mentioned that after it starts that your pressure is bleeding off and the engine dies. Sounds like it's having a problem maintaining the fuel pressure after start up especially when cold because the engine requires more fuel.
Your problem with the pump coming on intermitantly when you keep triggering 12v to the G term. is after the pump reaches 34-47lbs of pressure (without the engine running) it's primed and won't come back on again untill either the engine starts or the pressure bleeds off after a minute or two.
With your fuel pressure droping after start up and the engine dieing, sounds like the classic worn out fuel pump!

DarkKnight33

Well the pressure doesn't bleed off with the pump running, the pump never comes back on. Secondly, the pump doesn't know anything about how much pressure is in the fuel rail.

The prime cylce seems to be misunderstood in this thread. The ECM triggers a 2 second prime from the pump when you first put the key in RUN, then it's supposed to trigger the pump again during cranking. There is no sensing of the fuel pressure done by any part on the car. Actually, it's a huge oversight, as a code set indicating low fuel pressure would help in identifing the inital problem extremly easily.

Anyway, the point is it doesn't matter what the pressure is in the rail. When the G terminal is given +12v, the pump is supposed to come on no matter what.

I'll take a close look at the relay tomorrow. I'm *really* hoping it's the relay. I have like 4 extras, and I'd hate to have to drop the tank.

sqzbox

Doesn't your engine have the oil pressure switch that's supposed to send a signal to start the fuel pump when it see's oil pressure when the relay goes bad? In that case, your engine should still start and run but just take longer because oil pressure has to build during cranking. I don't know about the 5.7 but my 88 LO3 has one and that would eliminate the bad relay in your case if you do. Now it sounds like an electrical connection problem given the temprature variation in which it will start and run, or an ECM problem between open and closed loop.

DarkKnight33

Well, consider the age of the car. The oil pressure on the car has never, as long as I have owned it, registered correctly. Unless by some miraculas process the engine can maintain 60psi when at 0 rpms. I realise that it's a different sensor that is supposed to activate the fuel pump, but that might be malfunctioning too, or complety non functional. I'm not even sure if the L98 on my GTA is equipped with one in the first place.

sqzbox

If you do, it should be just above where the oil filter screws on.
Mine looks like an old style electric oil pressure sending unit.
At least, your gauge reads something . Mine starts cold at 30psi and drops to 0 after warm up . The first time I noticed it doing that I freaked . I went straight to AZ and got a cheapo direct pressure for like 10 bucks and slapped er on there.
I found it runs 40 lbs constant execpt under 1,000 rpm and almost 50 at 5,000. I've only had it to the end of the orange (5,500) one time and that was an accident I've got 145K on it and I don't want to stress it too much being the engine hasn't ever been apart. Right now it's sitting in the garage collecting dust. That thing you were talking about, the EGR and Bocsh O2's, is freaking me out I've got an AZ replacement EGR valve and a Bocsh O2, and a control solinoid I bought there too.
I have come to the conclusion that for some reason, the ECM isn't grounding the solinoid during open loop and as soon as it goes to closed loop it tries to ground it twice for 2 sec. and lights the SES light throwing a code 32, (SOMETIMES) SOMETIMES it will go 100 miles with no problem. Sorta like a nagging wife

Gumby

not my car but this may help

sqzbox

And your probably glad it isn't too! That has got to be the hack job everyone claims is crap and I have to agree. Looks like someone just started cutting away with no forthought at all!
I've got an acess hole too but it's covered nicely and doesn't go past the bend in the floor pan weakening the structual integrity.
If you go to the TBI forum and read the post "for those who did fuel pump access door" you'll see some pic's of some access door's done right!

Gumby

funny how GM didn't get to making an access hole until 99 then canced the line in 00.

Gumby

will it start with either?

see

https://www.thirdgen.org/techbb2/sho...hreadid=348900

sqzbox

Either it will or it won't. You mean ether right?

D's89IROCZ

See I woulda figured that your no start condition is cat related. The rotten egg smell ..... anyhow if its shot/clogged it will cut out the motor . But I also seen you had a low voltage at the coil . So maybe you have a couple issues .

As far as the relay clicking on sometimes and not on others . I am thinking the relay is bad .... maybe the pump is too , but I would replace the relay first before diveing into a pump

Gumby

will it start with ether, startin fluid???

Side note 4 rest


The fuel pump fuse is not near the battery. Its on the other side.
Looks like a weather pack conection but just has a fuse inside.
good size red n orange wire run to it.

zrated57

I think batteries are on different sides in Firebirds than they are on Camaros! So that would make it next to the battery on one and not next to it on the other! Correct me if I'm wrong.

sqzbox

Ok, which ever side the battery is on, so will be the main hot wire feed for the ECM. Follow that to the fuse and WALA!