ive got a 91 b4c 350 tpi camaro and i have been having some issues with it. So far i have currently changed a couple injectors, distibutor, fuel pump, computer and map sensor. What the car is doing is it idles perfectly and runs good but when you put the gas to the floor it just stalls out and will barely run. If you turn the car off and restart it; it runs fine until you put it to the floor. have checked wiring and it has been tuned up as well as rebuilt fuel regulator. now all this work was not done to repair this problem but this is the newest issue and i dont want to just start throwin anything at it i dont have to. Thanks

 

im having a very similar issue with my 91 z28 5.0 tpi i know i have a bas vss(unrelated issue) and a bad cts as well as o2 sensors...i will be replacing cts(coolant tempp sensor) and 02 this weekend if this helps me ill post an update here...good luck!

 

I have had the similar problem happen to me. But I fixed it, So... (in situation) It will start up, run fine. You can drive it but only while pressing the gas down slowly and gradually. Then right when you start to put more gas on it... It starts to like "hic-up" if you will. It starts to like boggel out and seems like it wants to stall, sometimes it does, sometimes it just runs REALLY REALLY sluggish if you hold the gas then right when you let it go... it runs perfect. Add a "little" gas it runs smooth. And I mean a little. Add anything more than that and on it runs like ****...

Sound like your problem?

But yes, If I am right. That is deffinitely the fu

 

yes that is very similar to what i am experiencing. almost like the fuel pump is weak but it is new, or a fuel loss problem if you will. hoping to get this thing goin soon so i can quit driving my truck, thanks for replies

 

Try attaching a fuel pressure gauge and monitoring pressure while you drive. Recreate the failure and look for pressure fluctuations. Also, use an old ignition wire to attach a flash bulb type spark tester where you can see it while driving and watch for spark drop out when the problem is occurring.

If you can get access to one, use a scan tool to monitor datastream while driving and recreating the failure. Watch for injector pulse to drop off or freeze.

 

i replaced my cts sensor and put new o-rings on my fuel filter fittings and rebuilt fuel psi regulator...running better now the stalling has been resolved maybe one of these things will help you?...my fuel filter was brand new and i kept smellin gas,thought it was rich until on a rainy day saw the rainbow on the ground by the filter..hence orings

 

thanks guys ill try those things and see if anything helps

 

well iforgot that i had already changed the coolant temp sensor a while back and there seams to be no sign of leaking around the fuel pump, any other ideas before i just scrap this car!

 

egr possibly?

 

Get it looked a by a Very Experienced Master Mechanic. If you've gone all the way to the point to where you've done everything that you could by yourself and just got sucked into replacing and repairing parts... Take it to a Hot Rod Shop. Because that is the exact thing that happened to me but worse. I had your problem and then a few months down the road... Just stopped all together. I took it too "8 referred too good Auto Shops... Either they didn't put much effort into it... or they just didn't wanna get into it.

So finally... I took mines to this Hot Rod Shop that I've seen tons and tons of Fast and Old Muslce cars at all the time for the past 6 years... Just never thought anything of it.

Go it towed there, put 200 down for inspection and diagnos of wiring "Crank, no start condition" Few days later... He told me some things... Very informational things to why my car wasn't starting or it was boggling down" Then an extra $750 to fix everything. It is in the process of being fixed right now...

And TRUST ME! I WAS SO MAD BEFORE ALL OF THIS! I Built the Trans Up, the Motor, The Tires, Ignition system and all worth over 10 grand...

Put it on Craigslist for $900 Got like over 200 calls on it same day... (That was a wake up call) So I said... Fine, I try one more time... and instead of me doing the work... I let a very well known and good Mechanic look at it... "Who actually was interested in working on my car, and WANTED to get it running for me" He must have a love for muscle cars or something... It's in the process right now. Meaning It had been sitting and not starting for 1 year now... So... Don't lose hope man...

Get that BABY RUNNING!

Oh yeah, and I didn't even have the money... I had to barrow it (that wasn't easy either, I had to literally convince someone for like a week straight why they should give me $600) So don't lose hope!

 

have u changed the fuel filter? that would be the first thing id do. maybe cleaning the throttle body too could help they can get gunked up and cause that. u should deffenintly get a fuel pressure gauge and hook it up. also does it feel like it misses at high rpm or does it just stall out and die? it doesnt sound like u have a serious problem just a matter of finding the problem lol ive seen cases before when i worked in a garage that the fuel filter was so cloged that the vehicle wouldnt even start

 

i just had the fuel pressure gauge hooked up to it tonight and it was reading around 45 with the key on. it has now decided it doesnt want to start, it will hit and almost start but doesnt. it did start first thing tonight and had a terrible miss to it and was really slugish with throttle responce, it eventually died and then wouldnt start back. it deosnt seem to miss when it was running before, but you could start it and it would run for a couple minutes and die then start right back up. The guy that had it before me replaced two injectors and replaced the fpr diaphram, he also changed the fuel filter as well. it also just goes into a nose dive and doesnt die but it wont hardly move if you give it any kind of throttle. thanks guys , tryin to keep good faith but dang ive never had a car to fight me so hard.

 

was the car running like this before u bought it? if so u said the guy replaced the fuel filter...dont laugh at me but check to make sure it was installed right. a buddy of mine awhile back had an old honda that wouldnt stay running after he changed the fuel filter, turned out he hooked it up backwards. do u kno if its throws a check engine light or SES light? if it does u could check ur TPS (throttle position sensor) or IAC (Idle air Controll valve) both should be on ur throttle body. if u have a multimeter u could hook it up to the TPS and with the car off u can test it, WOT it should be 4.5 to 5 volts. check what it is at closed, mid open, and WOT. i cant remember what the IAC is supposed to be tho. and if it wont start and u cant figure nothing out it couldnt hurt to test for spark either. Also when u tested the fuel pressure did it stay in the 40's when u had the car running before it died?

 

i own an 87 iroc now with a carb'd 350 but i use to own a 85 camaro v6 tpi. It had a MAF sensor (Mass air Flow) which can mess stuff up too if goes bad. but when i had the car it had a SES or check engine light that autozone couldnt check because it wasnt 96 or newer but its cause there scan tool they use is junk, u can buy a cheap one that will test it. but theres an obd conecter under the dash, im not sure about 91 but theres a good chance its OBD 1 and not OBD 2 but u can get a paper clip and bend it where it will touch 2 of the pins at the same time, if u get a haynes manual and look thru it, it will tell u which 2 pins to connect. when u do turn the key to the on position and the check engine light will begin to flash at u a few times then it will pause for a second and flash a couple more times. say if flashes 2 times then pauses then flashes 5 times the code would be 25, let it run a few times cause it could flash multiple codes. ur car u said is a 91, which most likely would be an OBD 1 just like my 85.

 

i will check that fuel filter out when i get off work to see if it is on correctly, i have seen that one before to. Never thought about it much just new it had the filter changed.i will check the tps and the iac as well. Ihave a code reader that does obd1 as well, and it kept throwin a knock sensor code up last time i checked it but it might have changed now.

 

That means, hook up your FP gauge, and duct-tape it to the windshield, and watch what the fuel pressure does AT THE TIME IT FAILS. What the FP does while sitting in the driveway idling is IRRELEVANT; what matters is WHAT IT IS DOING AT THE MOMENT OF FAILURE.

I seriously doubt it has anything to do with the ignition. Nothing that the ignition does really changes much at WOT. Fuel delivery, OTOH, .... yeah.

Not the "EGR". Something wrong with the EGR might cause a run-weird problem; won't cause stalling or a no-start. Also not the "timing". Leave those 2 n00b buzzwords out of your troubleshooting.

Similarly, the ECM won't tell you anything, because it has no way of knowing about any of that, unless it's SO lean for SO long before it finally dies, that it sets a "lean O2" code and lights the light. If the light isn't on, there's no info there to be had.

Go straight to the source of the problem: FUEL DELIVERY.

 

My car is doing the EXACT same thing. Just happened suddenly yesterday. My fuel pump and filter are fine. Both me and the mechanic I brought it to today are stumped. Will be taking a look at the injectors tomorrow, but it ran perfectly until yesterday, which is why we are so confused.

 

well i got it running again last night, changed the throttle body out with another one i had but it still dies after you reach a certain amount of throttle. i also changed the fuel filter with another new one since i didnt originally do it as well as changed out the regulator with an extra one i had. I also noticed when i shut it off i can hear vaccum leaking off for a minute or so. Dont know i am stumped!