Car running lean, any suggestions?

MATTKNIGHT · 06-11-2003, 08:11 AM

Alright, just to make sure it wasnt my fuel press I checked it w/ vaccuum discon. I read 39 psi at idle. Seems to me this should be good. I am getting fed up with the car so last night I started working on it. I took the top end of the motor off, including the heads. I saw no problems, even replaced all the gaskets to be sure no probs would occur. There is a crossover tub on the back of the heads, I plugged the heads instead of reinstalling the tube. During reassembly I decided to ditch all the emissions **** on the pass side of the eng. (down by the headers) I left the smog pump on and didnt plug it. The EGR is just flowing free. I plugged the vaccuum lines running to all the valves associated with the emissions stuff. After finishing everything I take the car for a drive. It fell flat on its face, stumbling like a maniac anywhere above 2800 RPM at wot. I am pissed. I cant get this thing to run right. PLEASE any more advice?? I am on the verge of selling this POS and buying an 03 Cobra.

strokedandchoked · 02-13-2009, 07:04 PM

ok, i have a 95 gt, 437 stroker, msd ignition, bbk CAI, the whole nine yards. I ran into the same issue you are and I went through all the ins and outs of changing my plugs, fuel pump, filter, lines, injectors, everything! Then i finally took it to a shop and had them run a comptression test and found out that i was running 15.1.... with that they re-mapped the ecu which was already chipped and programmed. if you have chipped it, the 94 and 95 5.0's tend to become retarted, in a timing sense once you think you have completed tuning. Reseting your computer doesnt keep the ecu from acting up once its already being dumb. Try finding a professional tuning shop, preferably a race performance/ racing shop and have them re-write your fuel curve. IF your car still runs lean, replace the ecu with non OEM one and see what that does. Everyone who owns or has owned a 94 or 95 has run into this same problem time and time again. Good luck and let me know how it turns out.

USMC302 · 02-25-2009, 10:48 AM

This is a pretty old post, glad you worked your issue out though.

lees gt · 03-08-2009, 03:52 PM

Matt,what was the problem in the end? I'm running a bone stock 94gt in the UK with the same problem..i've tried everything except the ECU.
Regards Lee

06-11-2003, 08:11 AM	#1
MATTKNIGHT Registered Member Join Date: Jun 2003 Location: MOUNTAINHOME, IDAHO Posts: 20	More info yet.... Alright, just to make sure it wasnt my fuel press I checked it w/ vaccuum discon. I read 39 psi at idle. Seems to me this should be good. I am getting fed up with the car so last night I started working on it. I took the top end of the motor off, including the heads. I saw no problems, even replaced all the gaskets to be sure no probs would occur. There is a crossover tub on the back of the heads, I plugged the heads instead of reinstalling the tube. During reassembly I decided to ditch all the emissions **** on the pass side of the eng. (down by the headers) I left the smog pump on and didnt plug it. The EGR is just flowing free. I plugged the vaccuum lines running to all the valves associated with the emissions stuff. After finishing everything I take the car for a drive. It fell flat on its face, stumbling like a maniac anywhere above 2800 RPM at wot. I am pissed. I cant get this thing to run right. PLEASE any more advice?? I am on the verge of selling this POS and buying an 03 Cobra. __________________ MATT KNIGHT 1995 5.0, msd 6al, msd coil, bbk longtubes, bbk offroad, 2 chamber flows, power tower shift, 98 gt wheels

02-13-2009, 07:04 PM	#2
strokedandchoked Registered Member Join Date: Feb 2009 Posts: 1	Re: Car running lean, any suggestions? ok, i have a 95 gt, 437 stroker, msd ignition, bbk CAI, the whole nine yards. I ran into the same issue you are and I went through all the ins and outs of changing my plugs, fuel pump, filter, lines, injectors, everything! Then i finally took it to a shop and had them run a comptression test and found out that i was running 15.1.... with that they re-mapped the ecu which was already chipped and programmed. if you have chipped it, the 94 and 95 5.0's tend to become retarted, in a timing sense once you think you have completed tuning. Reseting your computer doesnt keep the ecu from acting up once its already being dumb. Try finding a professional tuning shop, preferably a race performance/ racing shop and have them re-write your fuel curve. IF your car still runs lean, replace the ecu with non OEM one and see what that does. Everyone who owns or has owned a 94 or 95 has run into this same problem time and time again. Good luck and let me know how it turns out.

02-25-2009, 10:48 AM	#3
USMC302 Registered Member Join Date: Apr 2001 Location: Gallatin, Tn Posts: 1,326	Re: Car running lean, any suggestions? This is a pretty old post, glad you worked your issue out though. __________________

03-08-2009, 03:52 PM	#4
lees gt Registered Member Join Date: Mar 2009 Posts: 1	Re: Car running lean, any suggestions? Matt,what was the problem in the end? I'm running a bone stock 94gt in the UK with the same problem..i've tried everything except the ECU. Regards Lee

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