1994 GT Hood closes engine dies

50GTMach1 · Jun 20, 2011

I think i have an electrical problem. Car intermittently stutters when getting into the throttle and about 40% of the time when I close the hood and the engine is idling the engine immediately dies. no stuttering or struggling to stay running. hood closes, engine instantly dies. I just replaced rotor, distributor cap, and msd ignition coil. I have an msd 6 box installed. Anyone know if there are any wires around the engine that, if loose, could cause the engine to instantly die if the wires are jostled by vibration? the three ground wire connections to the body are secure (two by the battery, one by the passenger headlight)

the cel light is on and the codes are 334(334 - DPFE or EVP circuit above the closed limit of 0.67 volts) and 998. I think these have to do with the egr but i have the egr capped off at the header and where the egr tube connects to the egr valve. So I may have an issue with stuttering during acceleration because of the egr but it could all be electrical.

Thanks in advance.

beuchaw94gt · Jun 20, 2011

Just a guess but check and see if you ccrm is loose. Could be getting wiggled back and forth while driving too

Paul · Jun 20, 2011

Repair your EGR.

mustangshane · Jun 20, 2011

Check your CCRM. Also check the connector to the distributor. I found mine didn't snap together and could pull apart very easy. Unless because of the MSD yours is wired differently. Then check all of your box wiring and make sure everything is tight. Your EGR will not cause the engine to die when you shut the hood.

rideman · Jun 20, 2011

try tapping on the Mass air flow sensor while the car is running and see if you get the stalling. I had one go bad and every time I tapped it the car stalled.

rz5.0 · Jun 20, 2011

is your hood metal? is your battery tied down.
?

50GTMach1 · Jun 21, 2011

Thank you all for the help. I tightened every electrical connection I could find. only the electric fan connector was noticeably loose. the car did not cut off when i test drove however it still sputters and bucks during light acceleration from 2k through 3500 rpms. ive been adjusting fuel pressure but havent figured out a fuel pressure that does not induce or contribute to the uneven accerleration. i will try to reconnect my egr tube, clean the maf sensor, and go over basic tune up processes to see if i missed anything. i will keep you posted. i asked my tuner to turn off the egr function when i had the car tuned but that was over a year ago and i have no way to tell if the function was turned off in the computer.

thanks again.

hopefully my next post will have a solution and a good running stang!

50GTMach1 · Jun 21, 2011

another thought....ive been adjusting the fuel pressure between 28psi and 36 psi {with the vacuum hose off} and trying to find the right balance of fuel to air by test driving the car and smelling the exhaust to see if it is running rich. could i still be running the pressure too low and thus creating a lean condition so the car bucks from not enough fuel during acceleration. i have upgraded the engine with a e303 cam, 1.6 rockers, ported gt40 heads, and a cobra upper lower intake combo and had this combo dyno tuned. i was using haynes as a base guide for fuel pressure (between 30-45 psi) could the stuttering be from too low a fuel pressure. is 36 psi still too low even if I smell gas from the exhaust. (no cats on exhast setup (shorty headers, o/r prochamber, mac cat back.).

thanks again.

Paul · Jun 21, 2011

Fuel pressure should be set at 39 psi with the vacuum disconnected. Repairing your EGR will likely help with some of the drivability issues.

Paul.

50GTMach1 · Jun 24, 2011

removed, cleaned, tested valve with a vacuum pump (valve closed when i applied vacuum) and re-installed egr valve. car ran great without issues for 30 minutes. then cut off without warning when i came to a stop at a light, engine surged from 750 - 1500 rpm for a few seconds then on the trip home car would buck when cruising. engage the throttle and car would buck a little then accelerate. So im hoping that the old egr is failing. im picking up both a used (for free) egr and then a new egr (as back up) tonight.

I will post results.

thanks again for all your help.

50GTMach1 · Jun 24, 2011

update. and before i begin please note that my egr system was capped at the header and egr tube opening on the egr valve and that when i had the car tuned in 2009 i asked my tuner to turn off the egr in the ecu (which it seems wasnt done).

I installed the used egr valve and kept the header capped and capped off this used egr valve. car exhibited the same symptoms as the original egr valve...died suddenly, idle surge, bucking during accerleration under 3000 rpm. I pulled the same codes (511 and 334) after the test drive. the cel is on. Unhooked the battery +/- terminals to clear codes. Next i uncapped the original egr valve and header and reconnected the original egr valve and reinstalled the egr pipe from the header to the valve. going back to a stock egr set up. car exhibited same symptoms. same cel codes. tomorrow i plan on installing the new egr valve...I hope that the $80 for the new valve was worth it.

stay tuned.

50GTMach1 · Jun 26, 2011

Resolved...hopefully: 1994 GT Hood closes engine dies

installed new egr valve and since i was having some difficulty with exhaust leaking from the egr tube-header bung i decided to cap off the bung hole on the header and the valve. so far the car is running well without any abrupt stalls or bucking during acceleration. i vacuum tested both of my used old egr valves and they both closed at about 3 hg vacuum. the new one didnt close until i hit 5-7 hg of vacuum. only did one 15min test drive though. but so far so good. so thanks for all the help. :thumbsup:

ps. ac compressor went bad so removed it....now the passenger side window wont close.....sure is hot in my car....and the hits just keep comin!