Hey guys i am brand new to this site and this is my first 305 motor so bare with me...

To start car is a 1991 Pontiac firebird bandit II

I found the car in a storage shed and it was in amazing condition on the outside! Paint was redone about 3 years ago and you can't find a scratch,

anyways i bought the car and it was running great and never gave me a problem for over two weeks, then we were out on a car cruise and the car just dies... I pull over and i turn the key and it runs for about 2 to 3 seconds then dies... I have read multiple post on this problem but wanted to start my own.

So far i have checked compression spark to all plugs and installed new plugs since i took them out for the compression test, The wires are new and so is the distributor cap, So i am getting good spark to each cylinder so i can rule that out (for now) I also watch the injectors and they seem to cone just fine and right before the car dies they seem to spray a little more fuel to keep it running but still dies. If i disconnect the battery for a few minutes and re connect it the car runs for about 20 seconds before it dies,
However i found out that if i straight pump the gas pedal it was stay running but runs like complete crap. I have not done a pressure test yet but thought i would ask around first, Thanks

 

Welcome to TGO

Classic fuel pump symptoms - confirm with pressure check.

//RF

 

where do you connect a fuel pressure gauge? I do not see a fitting anywhere on my lines, or are you suppose to remove the fuel filter and go from that port?
I do see two lines right by my alt. is one a return line and one a fuel line? if so can i tap into these? thanks

 

I just bought the guage and I havent gottin around to doin it yet myself...but u can get the guage and TBI adaptor in a package at autozone for about 55 bucks.. I was told to hook it up next to the altinator...check some of my old posts someone put a pic up for me... the directions say to do it before the fuel filter...but that will be a mess waiting to happen...and u probly get a better reading in the engine bay..

**U gotta make sure U got the T adapter.. these cars dont have test ports for the fuel pressure

 

hopefully i have time to work on it before i leave for hunting this weekend, if not ill post my results when i get back to keep people informed.

 

did a fuel pressure tested and i ended up with 11 or 12 psi right around there... any ideas what else it may be?

 

I worked on a 91 Firebird 305 TBI that did the same thing and it was the ignition control module under the distributor cap. Went to a salvage yard got a whole distributor for $35 and it was good.

 

If it was spark wouldn't it not even start at all? it seems to have good spark when i have it running and pull a plug wire to look for that few seconds

 

thats what I thought too, but thats what it was. I could start this guys car and it would run for a little bit then just die, and if I gave it throttle it would even move but it ran like crap. Like I said I replaced the distributor and it was fine. Before I changed the distributor I changed the throttle body and it didnt fix anything.

 

well might as well give it a try, cant hurt to replace old stuff anyways

 

I re-read your original post. Here are couple thoughts regarding your problem. When you pump gas paddle this commands ECM to deliver more fuel, which would appears that you fuel pump is able to deliver. Before you dive into replacing all sensors perform basic diagnostics by shorting pins A&B in ALDL test connector with a paper clip. (See a section in technical articles how to do that). This is will allow you pull all (if any) stored DTC. Since the car sat in storage for a long time moisture condensation may have damaged MAP sensor. Try temporarily disconnecting MAP (mounted on the fire wall) and see if engine will idle. Disconnecting MAP will set DTC (SES light may turn on) but if engine is idling steadily (roughly more likely) MAP sensor probably needs replacement.

//RF

 

could be the fuel pump but normally it wont die while driving

 

So I replaced the ignition control module, no changes however I tried the map sensor and it will run longer now... But still dies so new map sensor and... Nothing, so I burrowed a computer scanner and my tps reacts super slow to any pedal the volts are very slow so I am trying that tomm,

 

sorry man, it worked for me. It really sucks chasing this kind of thing around.

 

new tps and same problem, any ideas are appreciated

 

Did you perform ECM self diagnostic check by shorting pins A&B on ALDL connector???? Post #11.
If there are no set faults replacing sensors might be a waist of money! If you have a scanner do you see any DTC's set???

//RF

 

when he checked it on the computer i had no codes that he found, The only one i would have was if i messed with the map sensor, It was showing 4.75 volts so he wanted me to unplug and then re plug it in to make sure that was correct

 

That's correct - unplugging MAP sensor would set Code 33 (MAP sensor reads high voltage, low vacuum at idle).

Another possible culprit is a stuck open EGR (especially at idle)

From the symptoms that you are describing it still looks (to me) like you are loosing fuel pressure. Yes, I know you verified the fuel pressure, but did you monitor fuel pressure while engine was running - stalling? It is possible that you have a bad fuel pump relay and oil pressure switch. The two provide DC power to in tank fuel pump. However, oil pressure switch (especially high millage) might be intermittent and it is common for relays to fail (I have several in my collection). On a third gen fuel pump relay is mounted on the firewall next to PB booster and oil pressure switch is screwed into oil passage just above oil filter. If fuel pump relay is fully operational you can temporarily disconnect oil pressure switch connector. Connector should have orange, gray (and sometimes third wire - brown). Orange and gray are 14 AWG and brown is smaller. The gray wire is connected to the circuit that feeds DC power to the in tank fuel pump. Orange is +BAT - so be careful! You can set up DVM to measure DC voltage between Gray wire and ground - this way you can verify that in tank FP is getting DC power. ECM monitors DRP pulses from dizzy and actuates FP relay control circuit (green/white ECM Pin A1) - oil pressure switch acts as fail safe device if FP relay fails. If both are flaky - well, you have a problem. By disconnecting oil pressure switch connector you'll be checking integrity of the FP relay circuit.
Do you think you can do it?? Questions??

/?RF

 

sorry for the long way away but i was working on a few other things, Anyways i finally got a fuel pressure gauge and adapter...and 2-3 psi...so i cut the trunk hole and replaced...now at around 13-14. Car runs great! ah it feels good to be back up and running thanks for all the help