musclecar70sfan

iTrader: (1)

Hey guys, well I've recently had this problem with the car (description in profile <<<<<) and I'll try to keep the story as short as possible:

Last Saturday, I decided to take it for a ride around my neighborhood, and when going up a fairly steep hill, the engine started sputtering and bogging (as if out of gas) and finally conked out. It refused to start on the hill, so I poured about 3 gallons of gas since the gauge said empty, but still nothing. Maybe a pop or two while cranking, but it never started. So I begged the neighbors to help me push it up the hill and into my driveway (30 ft away). Still, on level ground it refused to start. I sprayed a little starting fluid into it, and it sprang to life. It wouldn't restart on its own for a few minutes (without the fluid that is), but later it would. So assuming a gunky fuel filter, I backed it onto some ramps and then decided to rev the engine a few times (with the rear lifted about 8 inches), and then it started doing the same thing it did on the hill and eventually died and wouldn't start, even WITH starting fluid (it would burp for a second then nothing).

I replaced the fuel filter, and the line going from the tank to the filter at the same time since it was so rusted that it sprung a leak while I was changing the filter. I finished that today, and the car still wouldn't start on its own (was still on ramps). I poured in 5 gallons of premium gas and still nothing. I tried the starting fluid, and it fired up. It would also restart on its own without the fluid. However I tried revving it, and it started dying past about 2500 rpm, same symptoms as before. It stopped doing that after a while, so I felt confident enough to take it for a quick spin on the hill in front of my house. Sure enough, when I hit the gas to go up the hill, the engine started sputtering/surging... and died... again. Fortunately I got it to start (barely) again and got it into my driveway with it dying while I pulled in, fortunately I was able to coast the car down. Now it won't start with or without starting fluid.

I'm thinking weak fuel pump, since the pump primes every time I turn the key (it usually stops after a couple tries when there's enough pressure in the system, at least that's my guess why it usually stops).

Some backup on my diagnosis would be great before I order a new pump on ebay. And here's another thing:

http://motors.shop.ebay.com/Car-Truc...l=Trans%2520Am

Why are some pumps $20 and some $65? That's a BIG difference!

camaronewbie

PLEASE do yourself a favor - if you are dropping the tank to redo the pump, do not get an ebay pump - you don't want to do this again anytime soon. Get a CarQuest pump - it's a GM DElco pump, but cheaper than the stealership.

Have you checked the fuse beside the battery in the fenderwell?
Have you checked the fuel pressure?
Have you checked the Oil Pressure Sending Unit? (it also feeds power to the fuel pump)
Have you checked the fuses in the fuse box?
Have you checked the fuel pump relay?

I'd at least do all of these things BEFORE I went through the trouble of dropping the tank.

musclecar70sfan

iTrader: (1)

Well if a fuse was the culprit, wouldn't the thing not run at all? Since I do hear the thing buzz when I turn the key.

And you're gonna have to explain to me all of those points you have except for the first and fourth ones. Sorry but I'm kinda new to this. Thanks!

musclecar70sfan

iTrader: (1)

And trust me, replacing the pump will be a LAST resort for me. I REALLY don't look forward to doing that.

And I forgot to add, I bought this car about a week and a half ago and it's been sitting for a year before that. There was very little fuel in the tank so maybe the exposed pump got corroded a bit?

five7kid

iTrader: (14)

Gummy, decomposed gasoline is more likely than corrosion, although corrosion is a possibility.

My ISP is blocking your eBay link. Do you have item #s? I can usually pick it out of a blocked eBay URL, but you must have linked a list or something.

A fuel pressure gauge is a good investment. Although I don't have an EFI 3rd gen (yet), it has been very useful for diagnosing my other EFI cars.

The start relay is timed, not pressure operated. The run relay is energized by the ECM. You need to verify the pump is powered beyond the start timer, which is what camaronewbie was getting at.

musclecar70sfan

iTrader: (1)

five7kid... I'm kinda getting what you're saying, but it's still kinda greek-ish for me. LOL

And here's an update, I tried firing the car up today and it will by no means start without fluid (a few pops but won't start). It barely starts with fluid but it'll only idle. When the tach hits 2000 rpm the thing just quits. And I do hear the pump going for a couple seconds after the car dies if that makes a difference.

musclecar70sfan

iTrader: (1)

Oh and I can't find a part number, but here is a direct link to one of the listings if that helps:
http://cgi.ebay.com/ebaymotors/PONTI...=p4506.c0.m245

musclecar70sfan

iTrader: (1)

And here's a thought, maybe the ECU isn't sending enough juice to the pump? Does the pump operate at a constant speed or does it work harder as the revs go up?

transam85dudeman

get an ac delco pump. it could be the pulsator slipping off the pump. its in the tank connected t o pump. try this . prime the pump with key, then go under hood and press the schrader valve on the fuel rail passenger side. if it sqruits out fuel about a lot, then your pump is good. if it dribbles then its bad or the check valve on the fuel pump. also if you replace the pump ditch the pulsator and use a neoprene hose with stainless steel clamps. its included witht eh ac delco pump. that is an oem pump, the dealership would hook you up with. stock. and report backs. are you getting spark. somtimes the dizzy clamp bolt can get loose and it would physically advance the dizzy.

musclecar70sfan

iTrader: (1)

Yup I'm definitely getting spark since whenever I spray in starting fluid the engine burps. OK I'll take a look into that, thanks for the tips. Any more?

musclecar70sfan

iTrader: (1)

Update: I put in a new battery today since the trans am needed one anyway. I decided to try to start it and see what happens. And it fired up instantly. It ran beautifully for a few minutes. It revved just fine; bringing it up to red line didn't choke it one bit. I let it idle on the driveway to see what happens but about 10 minutes later when I went to rev it, it started doing the same thing as before (cutting out as if out of gas). It died and won't start. It wouldn't even pop or burp. But I hear the pump going. I'll check the fuel pressure with a gauge (some how-tos would be great since I never did this before) tomorrow.

Here's a thought, initially with the engine running and the new battery, the voltage gauge was reading about 14.5 volts. It dropped to 13.5/13 while it was idling. Maybe the alternator is bad and was struggling to supply juice to the injectors?

Again, I'll probably check the pressure in the fuel rail tomorrow. Some advice would be great and what kind of numbers I should be seeing.

And is there a chance something is wrong with the "spark" side of the equation? Rotor going bad perhaps?

transam85dudeman

it maybe the coil failing on ya, sure it works when cold, but when heated it fails, happend to me. i replaced the plugs, wires, ignition module, pickup coil, condenser, and after ten minutes it would die, and wouldnt restart ..only after a day would it resart for 10 mins and die and not restart...i finally replaced the coil. and it didnt die on me anymore, especially considering my tow bill hit 80 bucks.

for psi numbers you should hit 38psi-43psi. the regulator controls the amount of pressure to injector via engine vacuum.

musclecar70sfan

iTrader: (1)

Hmmm, my car seems to be having similar symptoms to yours. I feel stupid for asking, but what is a coil, how much does it cost, and is it a DIY job?

musclecar70sfan

iTrader: (1)

Oh and did it sound like it was running out of gas before yours died?

transam85dudeman

you have an external coil, its on your firewall- under the hood, its has a spark plug wire going to it, and the other end goes on the distributor in the center. Youve got an external coil. mines a coil thats located in the distributor cap. it is diy, but beware of 36,000 volts if you touch the connector when the engine runs. its ok when its off though, you can pick one up at autozone, tell them your car info. they go for about 20 bucks. made in mexico, unless you go to napa then theyre made either in the usa or china.

Btw to answer that dudes question about gas. Yes it sounded like no gas. but the pump would prime. i was at a stop when it happend and as soon as i idled to accelerate, it stalled, then started for a second -surged but when i shifted into drive it died. it took two days b4 it started again. same thing happend. i was pi$$ed. so when i went replaced my coil, it ran... and viola, the neighbors were all cheering and the kids were doing wheelies on their bikes cheering, cars on the street were honking, airplanes were flying over and parachuting, fireworks were in the air, cats and dogs were singing, and global warming stopped, peace on earth nah nah just kidding but i felt that way inside after getting her running again.

musclecar70sfan

iTrader: (1)

HAHAHAHAHA I love the happy ending. BTW the dude asking about gas was me too lol. Thanks for the tips man, hopefully I'll be able to do this tomorrow!

entrig00

iTrader: (1)

Hey hows it going. First of all I'm having the same problem so I'm hoping that it has to do with the coil....I also am not to familar with coils. I'm hoping it is something like coils, I scheduled to change out the fuel pump this coming Tuesday or Wednesday and not looking foward to it.

Let me know if you find anthing out, I like you am hoping that it is not the fuel pump.

musclecar70sfan

iTrader: (1)

Well I'll probably be doing this tomorrow so I'll let you guys know what happens right away.

musclecar70sfan

iTrader: (1)

Update:
Well I just checked to see if the engine is getting spark and it seems to be getting it. I removed the main wire off of the cap and cranked the engine to see if it's doing anything. There is a spark, but it's not consistent at times. Maybe the coil is going bad?

transam85dudeman

its cheaper to get a fuel pressure gauge at autozone than to replace the pump. thats how i eliminated the fuel pump issue. i figured it wasnt the coil since i was getting spark, but it turnd out the coil would fail on me after 10 minutes. could be as small as your pickup coil (different coils) it tells the computer when to fire. besides that one time i described above, i actually had another time when my car would run and after 1 hour after turning it off, it wouldnt start, upon inspection i found out the pickup coil's permenant magnet was broken in 5 different spots. i replaced it and bam. workd. but the dizzy has to be removed in order to replace. sometimes it be nice to open a shop only for third gens.

entrig00

iTrader: (1)

Thanks for your info...I'm going to try to change out teh coils and see if thats the problem. Whats the dizzy and do you know if theres a way to check the fuel presure rather then using a fuel gauge?

Thanks for your info and help transam85dudeman

how do you check the coil and is it called the pick-up Coil, $11.99 ?

transam85dudeman

theres the ignition coil and a pickup coil, youre ignition coil should be mounted on the firewall and have spark plug wire connected to it going to the center of the distributor cap. the dizzy is called the distributor. the distributor is called the dizzy, its short abberv. to check the fuel pressure without spending the bucks, there should be like a bicycle valve on the fuel rail connected to the injectors. (dont press the a/c valve or youll have an earlier christmas. press the fuel rail down and see if fuel squirts everywhere and makes a mess, after you turn the key to on position and her the fuel pump buzz

musclecar70sfan

iTrader: (1)

I'll try that, thanks for the tip. And when you said your coil was failing after 10 minutes, did you check to see if it was making spark by disconnecting the wire and cranking it?

transam85dudeman

no i freaked out and cursed, my car. then after getting wasted i "walked to get new plugs and wires" curse more when that didnt work. i beat the tow man in a race on my bike. and waited for two days b4 it started. it worked ten minutes, then after testing everything nothing seemed wrong with it, worked again for ten minutes. then stalled. so i just ended up rebuilding the distributor.(except the coil) it work, ha for ten mintues replaced the ignition coil finally and bam workd. i read up that it fails after 7000 discharges, thus heating up that day to a point where one loses his GF

musclecar70sfan

iTrader: (1)

hahaha I love the story. How many miles did the car have on it when this happened? Mine's got about 98,000. If it fails after 7,000 discharges, then mine seems to have died right on time. LOL

OK I got the coil and I'm gonna install it soon, assuming the weather holds up today.

transam85dudeman

its fails after 7,000 discharge, that when it heats up during a typically warm up. but a coil can charge and discharge a tens of million times+. but when it fails when hot, then 7,000. i have 117,000miles. ive had everyproblem electrical you can think of. when i bought the car it stalled every stop. hehe. i got that beast beating mustangs and so fast that it takes takes 30 seconds to register on the speedo (85mph) after topspeed after letting off throttle.

musclecar70sfan

iTrader: (1)

lol nice. Thanks for the tips, and I'll be replacing the coil now and I'll let you guys know what happens.

transam85dudeman

make sure the spring in side the cap under the coil bottoms out with the rotor

musclecar70sfan

iTrader: (1)

Well I put in a new coil and it fired up right away, but it died when I turned the steering wheel. It started up right away again after and would idle, but it would start cutting out when I hit the gas. It wouldn't go much past 2300 rpm. It started idling roughly after and when I went to turn it off and restart it, it wouldn't start again.

And I checked the fuel pressure by pressing that little bicycle valve, and I got a decent squirt. It shot up a few inches until it hit the engine and lasted for just a tad less than a second. Is that what I want to see?

musclecar70sfan

iTrader: (1)

And here's another question... does the pump operate at the same speed continuously or does it work harder with higher RPMs?

transam85dudeman

your pump pumps over a 100psi but the fuel pressure regulator only allows 42psi in the rail. when the engine increases rpms the regulator's vacuum link allows more pressure. but usually the pressure drops to 38psi. thats great it started up, suck it didnt stay idling. pickup coil could be shot.

musclecar70sfan

iTrader: (1)

Ugh.... I guess I outta start diagnosing. I'd still much prefer a bad pickup coil over a bad pump. I have a Haynes service manual and they showed how to test one with an ohm-meter so I'll have to get my hands on one of those and give it a shot.

entrig00

iTrader: (1)

Any world if he got it running?

nomad350Z

Its a LB9 TPI.....does it have stock fuel injectors? I've heard nothng but trouble from the Multec's......Get an Ohm meter and measure the resistance on each injector, should be around 14 ohms. If one shorts out, it'll boggle your computer.

Went through the same problem with my TPI,so its worth looking into.

entrig00

iTrader: (1)

Hey never thought of checking that...


I'll try that out and see what happens...

ninetyone

iTrader: (2)

Hey man, definately check those fuel injectors! I had the same problem on my 91 TPI and it is VERY common on our cars. Plus, you will not see any codes if you have a bad injector. Get an ohmeter or a mulitmeter and check them. They should all be around the same. Set your meter to test ohms at the 2K setting. Injectors should be around 0.013 to 0.018 or so. If you find one at 0.003 for example, it is dead. Also , i would look into checking out your ignition control module. It is under your distributor cap. Most Autozones or auto parts stores now test it for free. Just make sure you use thermal glue underneath of it when reinstalling it. If it is bad , then it will usually act up when the engine warms up due to heat. Let me know how it goes.

entrig00

iTrader: (1)

That makes sense. Now did your camaro do the same thing that its doing with mine? At first it starts very good and revs but when it warms up it acts up. Now was it your injectors or coil that went out. If it was your injectors wouldnt it act up when trying to start or does it take time for it to act up?

As for the coil I had it tested at autozone and they said that its fine, now is it known to go out within time, like after five minutes or so? Meaning they tested it but they can only test the begging or the start. is it possible that they test fine then withing five or ten minutes they take a dump?

ploegi

Injectors can test fine when cold, but, when the warm up.... they start failing. Always ohm check injectors when the engine is at operating temp. (if you can get it there.....)

transam85dudeman

when i tested my bad coil, it passes. however. it does take a dump after 10 minutes. perfect coil for the greedy mechanic that wants his customers back, muahh.

musclecar70sfan

iTrader: (1)

Thanks for the responses guys, but I got the car fixed at a shop back in September. Turns out it was bad injectors, I got em all replaced with brand new Bosch 3 injectors. Runs like a charm now. It set me back over $500 but at least I have my baby running fine.

Sorry about not posting that up sooner.