F5GTS331

ok so here's the mods 306 gt40 heads exp intake tfs stage 1 cam cobra 1.72 rr's u/d pullies cai shorties o/r x flo cat back msd ignition 190 lph fuel pump fp regulator timing 13*

car runs real rough at startup and take off and i mean like a start and go take off when the engine is cooled doesn't matter tem outside then after a min or so it'll give me a ***** to the wall run and then it start acting up again when i shirt fast as if i were racing it studders for like a second but if i shift slowly it seems to be ok. the only codes it's given me is a code for the ect and tps and egr but i did swap the ect wires around cuz i had to replace the connector and i thot they might be backwards and it seemed to help just a littl but not a lot and i've noticed it runs cooler since i did that but not a good cooler a to cool temp. i also suspect a computer failure cuz someone at sometime has spliced two wires with ground wires but i have no clue why. my radio also doesn't play sound when thecar is running it does when the car is just on or in the acc position and the speakers pop a little when i turn the key on

i'm at my wits end with this guys so please help!!!!

mjr46

well number one a faulty ect sensor and or tps can cause your problem and the egr and ect connectors are simialr and you need to identify the wiring color code for those circuits and compare to where you have them plugged in so as to have not crossed any wiring..anyway you need to resolve these codes and once they are resolved.... retest...... and on your vehicle you should have no cooler than a 180 stat since it is efi

1990NOS!

sounds like connections, and not a tuning issue (with those mods you wouldn't need one, it'd run smoother but no gain at the track). and +1 with the 180thermo'-- 5.0's makes their peak hp around 175-185 degrees.... You didn't say anything about bucking you around, or sputtering--- but what about your fuel ratios? have you checked it?
Stills sounds like wiring/connector issue though... just need to PAD (pay att'n to detail). Someone did take shortcuts though, and now you gotta fix'em... GL

F5GTS331

it has the stock thermo in it. it does buck if i understand what you mean. i don't have any way to check the a/f ratio the fuel pressureis set at 39lbs with vaccum off and plugged. i think my next step will be to undo the grounds spliced into the computers harness and see how it runs and see if i get any diff codes and try to replace those sensors i guess i haven't checked codes since i swapped the ect wires around so......... i might do that now

F5GTS331

ok i got these same codes still 118 121 and 122 same as before i swapped ect sensor wires around 118=ect voltage too high 121=tp sensor voltage hihger or lower than expected or signal voltage inconsistent with intake air flow that one kinda concerns me a bit so what would cause that? the 122= tp sensor voltage to low so that's what i got so far i still have to unhook the spliced ground into the computer that may open up a whole other bag of worms

F5GTS331

so any more suggestions?

94StinkinLincoln

i have 1.32v at idle, i have gotten 2 sensors for it, both read the same thing. not sure how to get the voltage down, if i start oblonging the hole, it might crack. i 2 think mine is slower than it should be, but its not crappy, 0-60 in 6sec is slow for a "built" 331 imo(thats what mine is btw)

F5GTS331

that does seem kinda slow for that my buddy has a 331 in his fox and it was quick seem like it'd be a lot quicker than 6 sec 0-60 let you know if i find a way to fix it