Somebody please help me out here. My neighbor's 88 GTA 350 will not start. The problem started a few days ago and we replaced the fuel pump and replaced the MAF (both needed to be done), but the car will still not start. The car fires up initially, but then dies. It seems like anytime you try to hit the gas, the car wants to die as well, but no gas or flooding happens. Also, to makes things even stranger, if I stick my hand in front of the throttle body and completely choke it off, the car will idle until I take my hand off the front of the throttle body. Please give me some help here. It seems to me that the car is not getting enough fuel. I am basing this upon the fact that the car runs when extremely choked, but dies when I remove my hand. The fuel pump was replaced, what can be the problem? We have not changed the fuel filter, can this be the problem? How about a relay? Any help would be greatly appreciated, because we need to get this car back on the road.

 

Cousin,

There are a couple of things that glare out at me in your post.

You stated that you changed the MAF, but the car runs when you choke it by holding your hand over the TB. The intake ductwork MUST be installed so that all intake air is measured by the MAF sensor.

Reinstall the ductwork, clear the error codes, and try it again.

Second. you should always replace the fuel filter before or in conjunction with a new fuel pump. Test teh pressure at the right fuel rail:



You should be getting at 37 PSIG +/- 3 PSIG with the engine running, or 44 PSIG +/- 3 with the pump running, engine off.

You obviously have ignition and some fuel pulses, or the engine wouldn't run at all.

You may have a major vacuum leak, which is indicated by your choking the engine to get ot to run. In essence, you are eliminating all IAC air by doing that, and that intake air must be coming from somewhere. Check the PCV, brake booster, and EGR valve for leakage. You can temporarily disconnect and cap those vacuum line fittings to test the system.

Let us know...

 

Thanks for the help vader. We tried to get the car to run with all the ducting in place and it wouldn't, but, when I pull off the ducting and place my hand over the TB, it will idle fine. Also, the fuel filter has now been replaced and the problem is still there. The car ran perfectly until the other day, so it hasn't been sitting at all or anything. Now, we tried the car with all the ducting in place, a new pump and filter and checked all fuses that I know of and the problem is still there. The vacuum leak makes alot of sense, so I will search around under the hood and see what I can find. Other than a vacuum leak, can you think of anything else that would create this problem?

 

well not saying that this is it, but when i had that problem, it was my computer...that was it...i was replacing everything fuel pump fuel filter maf fuel pressure reg. and all it was was a fualty chip...you never know take the chip to a dealer and have them test it...

 

sounds like a vacuum leak to me too. I don't see how you can create one doing the work you did though. Was it running this bad before you put the new fuel pump and MAF in? With the air ducting on, do you hear any hissing? Try disconnecting the battery to reset the ECM maybe.