I just bought an 89 firebird formula 350 ws6, it has some issues. The biggest problems are the manifold exhaust gasket on the passengers side is leaking due to the last owner losening it to get to the starter. The other problem is I can start my car and it will run pretty descent while its idling. It can run idling for an hour fine but when I drive it , it starts to die out and actually craps out on the road. It putters and if I give it gas it goes to shut off. Then after that all happens it gets worsr fast. A minute later it totally shuts off. If I wait 5 seconds it will start right up and I can get it to rev up to 3k rpms while in drive but it goes to cut off even faster then before. I cant figure it out. I have a half tank of fresh gas and replaced the air filter so far. The car was sitting for 7 years but it was staryed and ran . The last owner put a new fuel pump in by accessing it thru a hole he cut in the floor. And he put in a new starter also. Could the leaking exhaust gasket have effect with this problem or is it a fuel problem? Would a fuel filter be a possibilty? Cuz it wasnt driven for so long? Could it be a fuel pressure regulator? Please help .... Any insight would help me..... Thanks in advance

 

If you haven't replaced your fuel filter yet, do so ASAP. Then ohm out your injectors to make sure they are within spec. Do all the tune up items, spark plugs, wires, cap, rotor, etc. since you'll need to do them anyway if the car was sitting that long. Reset IAC for minumum air and reset the TPS. Change out all your fluids. Verify correct base timing. I'd also check out your cats, see if they are clogged.

In short, do the tune up to make sure all those wear items are good since bad parts of those can cause your problems then begin diagnosis.

 

Would the exhaust manifold gasket leaking have anything to do with the car dying after 15 minutes of driving? You dont think it's vapor lock? Do you? It's just odd that I can have the car idling for upto an hour and it doesnt do it ( the hood is usually open when its idling cuz im trying to figure out the problem ) is it getting so hot from the exhaust leaking on the passenger side when the hoods closed that it makes the fuel boil after 15 minutes of driving? It foesnt have the cCEL on, but the last time I drove the car it turned on for half a second when it sputtered and was right about to die , but the CEL went right off . after that all happened, I cranked it and turned over with no problem, then when I tried to drive i couldnt get it to go over 3000 rpms, if I tried it would go to shut down( like when I push the gas pedal it feels like it shut off fora second, then if I take my foot off it , it comes back on but I cant give it any gas or it happens again)then I can only give it so much gas before the rpms start to drop and it dies again. The more I do this the less time it runs. But it starts ok in between this happening. It feels goverened when it starts happening, and just gets worse. Sometimes I hear a pop in the exhaust under the hood or under the car....

 

Same car as you, only had it a couple months, but the PO spent 6 years chasing problems until he basically did what Jekyll says above. The finishing touch was 3 injectors ohmed out bad (remember cold and hot test). Car is stock runs like a champ with 99K miles.

 

Its not bad, it was just sitting for awhile. I just have the one issue with it dying out. I dont think its* the injectors cuz it doesn't run rough. And it drives fine for 15 minutes and then it starts to not let me give it gas , it slowly goes from letting me give it gas till 3000rpms till I can't touch the pedal, then it dies. I can start it back up and then it slowly starts again. Dont know why. Its driving me crazy.

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testing your injs is quick and easy. do it and shut us up!
also check your fuel psi, ign mod, pickup coil and the coil.
if all that checks out put a scanner on thee ole gal.
good luck!

 

Like I said. Do a tune up and make sure everything is within factory spec first. Do a search on the technical articles on the main page - there should be a tune-up guide. Better yet, pick up a shop manual and follow the procedures. The idea is to make sure everything is up to factory spec before you test out hard components.

Also, if your injectots are stock (grey plastic casing) there is a good chance they are bad. My GTA has 51k miles on it when the stock injectors went bad. These Multec injectors are an incredibly bad design. An injector may fire off fine when idling since the pulsewidth being sent to them is low, but as the computer demands more pulse from the injectors (ie when you hit the gas) and the car is under load (you are moving) the injector may be failing. So ohm them out.

Also, if your car is throwing codes, pull them to see what else is causing a problem. The method to pull codes should be in the techincal articles section as well.

 

I understand what your all talking about with the injectors. I'm just trying to see all the possible problems it could be so I can check them all. The reason I dont think its injectors is because I can drive for 15 minutes flooring it and it runs normal. It picks up quick and accelerates with no problem, but then out of no where it starts dropping in the amount of gas I can give it. And slowly drops till the car bogs out and I hit the gas and the car has no response( if I keep it floored it will pop in the exhaust and die) but after it shuts off I can start it and it moves but slowly dies faster. Im not doubting u guys I just want to see what else it could be. I appreciate all the help. Im trying to give the best description on my car problem. Could it be the cats are shot or have to do with the exhaust leaking from the manifold? Or vacumm line leakibg? what do I need to check the injectors? How do I go about checking them?

 

How do you test the injectors? What tools do I need? Whats the process? I'm also going to attempt to fix my exhaust manifold gasket. Is there any short cuts? I need to only replace tge passenger side. And how do you test tge fuel pressure? What size gauge do I need? 100psi? I need some guidance...thanks all

 

To test your injectors, go to youtube and type in the search field "how to ohm check a fuel injector." Google and the search button are your friends.

As for the fuel pressure, there's a schrader valve that looks like a bicyle valve towards the back of the TPI on the passenger's side fuel rail. Any fuel pressure gauge that has a GM adapter fitting will crew into this valve. Turn the key to on but DO NOT turn on the car, the fuel pump will prime for 2 seconds then shut off but this should be enough to give you a fuel pressure reading. Pressure should be in the 42-44psi range while the pump is running.

As for your exhaust manifold gasket, just take off the manifold and replace the gasket. Be sure to use a lot of penetrating oil like Kroil on the bolts before you start though. Breaking off a bolt head there sucks big time.

 

I just noticed my fuel pump makes a loud noise while my car is running (whining noise) what is that? Its a new fuel pump too. You can hear it inside and outside the car. It's louder outside. What would cause it to whine?

 

If it's new, it may just be a loud fuel pump... though I have a Walbro 255 and I can hardly hear it... but my exhaust is pretty loud too.

Fill up your tank. Most times, the sound is audible when the gas gauge reads quarter tank or less. The pump needs to be submerged in fuel to stay cool anyway.

 

I have 3/4 of a tank of gas. I just replaced the fuel filter and theirs no change in the fuel pump noise or the cutting out after a few minutes of driving. The car won't let me go past 3000rpms, as soon as it goes to 3k rpms it drops down if I hold the gas like its a rev limiter or governer. Could pressure in the gas tank cause it to act this way? I saw the white valve that sucks air in to depressure the tank and it looked old and had some kind of oil or something on half of it.could vacumm lines cause this problem? Oriac valve or fuel pressure regulator? Im lost , im gonna see if I can do the test for fuel pressure and test the injectors. Any other causes you might think it is? O and my car pulls violently to the right when I brake , if I dont hold the wheel ill crash into something. I replaced the calipers and pads in front and bled them . Whats that about?

 

It sounds like you have a whole host of problems. Have you tried doing anything we've told you yet?

You seem new to cars so I will give you some advice. Before you buy anything else, beg, borrow, or do whatever to save up and get yourself one of these:

Service Manual for 1989 Pontiac Firebird

Start reading and this book will have all the answers, procedures, and even pictures to every single problem that you run into. It was the best $150 I ever spent on my car.

As far as what else can cause your problems, could be clogged cats, timing, fuel related, may even be electrical because of failing computer, but who knows? I don't think you have done any of what we've told you yet so you can't eliminate the fuel problem, or the timing problem or any problem.

Good luck.

 

I'm trying to do everything I was told on here. Im just seeing what else it could be while I'm doing all the tests. I'm not new to cars its just nerve racking when I can't figure it out and figured if someone else had similar problems as I do then it would be easier to determine what the problem is then just checking random systems. The fuel pressure is 40psi. Now I need to check the spark &air systems. Ive noticed that my battery isnt the correct cca its 570 and its too small. Would that mess up the rpm range? I appreciate all you help , directions & quick replies.

 

I checked my injectors and there all good. Cold test was between 16.7 - 16.8. Hot test was between 17.7 - 17.8 . I noticed some vacuum lines were split so I replaced them. I also changed the wires and cap and rotor. The distributer inside looked rusty (maybe carbon build up) also had a white line painted on it(looked like someone put it on there) but the rotor want lined up with it. I tried cleaning the top of the distributor off with throttle body cleaner. It also has a code 44( lean echaust) I do have ab echaust leak arty the exhaust manifold on the passenger side.as I started the car after I did these repairs the car ran even WORSE then before I did them. Also now the oil gauge is acting up (before I start the engine it jumps up all the way and then shoots back down) then I start the engine but it is low but goes up when I press the gas. And now it sounds like a bearing is bad in one of the pulleys in front of the motor. When I press the gas it makes a squeel(just the 1st second when I press the gas after that it doesn't make the noise) . Its just feels like the car is stuck and has no ***** to go.

 

Any updates?? I have a 86 Z28 with the exact same symptons...

 

I havent tried anything else to fix it yet. Hopefully I can get it in the shop soon. Ill let you know what happens. If you figure out anything please let me know.

 

"And now it sounds like a bearing is bad in one of the pulleys in front of the motor."

Did you check to make sure one of the belts isnt just coming loose? My camry did that for a while, its usually just a belt. simple fix too. Also watch the pullys themselves, ive seen where they start shaking and cause a squealing noise.

You say it has a code for lean exhaust, to me this is kind of what it sounds like: The fuel pressure is supposed to be 42-44psi, yours is 40. Honestly, im not sure if that would make a big enough difference in performance to cause the problems your having, but if it is, I wouldnt be surprised. We are talking about 2-4 whole pounds of pressure you DONT have, that could absolutely be the problem. The comp is telling you that its running lean,and your fuel pressure isnt as high as its supposed to be. To me, id be seeing red flags all over the place. I think id be looking at that fuel pump, and heres why:

When the car is cold it runs richer, allowing it to run right, or close to it. Once its up to operating temp its no longer running a little richer to keep running and warm up, now its running too lean. Thats why the car goes from running fine and pulling great, to having no ***** and stalling. See what im saying? You also said the injectors are ok, so again, that would kinda make me lean more to a fuel delivery problem. Have you pulled any plugs and checked their condition? Are they white? That means the cars running lean. Very fast and easy way to help figure out if thats the problem or not. Dont just go and buy a pump and have it installed without making 100% sure that IS or ISNT the problem, because im not saying that it IS, only that thats what I think it is. There could be a blockage, pinch/kink in a line, it could be anything. You could also try seafoam, TB cleaner, MAF cleaner,ect to see if that helps. Put seafoam in the tank too! It definetly wouldnt hurt. But i do strongly believe its a fuel, most likely fuel pressure related problem.

You said theres an exhaust leak at the manifold, is it a crack in the manifold? Do you hear a ticking or slight puffing from the manifold? Because you do you probably just found your problem. (it wouldnt hurt to check the rest of the exhaust for leaks as well.)

I dont think i would consider timing to be the problem, but it could be. the balancer cover could have slipped, so until you have checked it to be sure - DONT rule it out. Its very easy to check/set timing, and you can loan a timing gun from most auto parts stores.

I dont think the battry CCA would affect it, besides you said it revvs fine and has power when its cold/warming up, so I dont think thats it.

I dont think its a vac leak either, if it was the engine would idle rougher than it should, it would make whistling noise where the leak is, wouldnt have as much power, and it would just affect it when its warmed up.

I know this is alot lol, im just trying to help as much as I can. Check all these things, and let us know what you find. Good luck!

 

The fuel pump is new , I checked the fuel filter after this problem started and it clear, nothing at all in it. The pump itself is loud outside the car. Im wondering if its a return line or pressure building up . The weird thing is I changed the cap & rotor and it runs worse and I sprayed tb cleaner on the distrubutor cuz it was rusty or had carbon build up and after I did that it runs worse and has a sqweek . It also sounds like a spark knock( inconsident tapping or knocking coming from the back of the motor by the distruboter) after spraying tb and changing the cap & rotor. I dont have pressure test so im gonna try to bring it to good mechanic that I know soon. Im just afraid of driving or running it and screw the motor upmore or worse , blow it up. Could it be junk on the gas tanl or clogged return lone? The fuel pressure regulator seems to be working because the vacuum line doesnt smell like gas. The thing is, I can run the car parked and it runs fine (I can run for 2hours) but as soon as I drive it, it starts to not go over 5k rpms afyer a few minutes then if you try to give it more gas it goes to shut down or back fire into the intake or front of exhaust, and it slowly gets lower and lower in rpms until it dies and then I can start it back ip after 10 seconds and then it starts having the problem at 3500 rpms and drops down till you cant touch the gas without it cutting off or bogging down. Its so frustrating I cant figure it out and I know its something dumb. Its not tge fuel pump thats new. So what elsr? I did tge sea foam in the tank and motor and intake and no change. Any suggestions would be awesome....

 

You may need a new tank... Read this thread https://www.thirdgen.org/forums/tpi/...ml#post5135941
Have a shop look inside the tank thru the filler tube with video. While fixing the car we had a used tank sent to us and it looked great on the outside but varnish looking sludge on the inside. Later...

 

Id also look into the distributor itself, you say the base was rusty so u sprayed it with cleaner, maybe should not have sprayed it, any moisture inside of the cap will cause spark to jump around everywhere inside of the cap, and well you know thats never a good thing, dont worry about that white line someone put on there, thats more then likely someone pulled the distributor and just lined up where the rotor was pointing instead of doing the whole # 1 cylinder TDC thing, I have seen cases that gave the same symptons of ur car, and it ended being the distributor itself that was faulty, it was the gear that rotates from the cam shaft was worn, had play it in, and was screwing up the fireing order big time

 

Have you tried the simple stuff; rotor, and ignition module?

See my signature for a helpful mental guide to keep you pointed straight.

Keep in mind also, it's VERY EASY to troubleshoot for a fuel delivery problem; all you have to do is re-create the dying scenario, and have somebody squuirt gas into the TB with a detergent bottle or something WHILE IT'S DYING. If it still dies when doing that, QUIT WORKING ON THE FUEL SYSTEM, because supplying more fuel doesn't solve it.

 

Oh... and it's NOT the "timing". "Timing" doesn't work fine for 15 seconds then screw up. LEAVE THAT ALONE and stay oriented TOWARD the problem, do not stop to gawk at shiny things beside the path.