hello, i have a 1986 sierra cosworth that will start, idle, but just wont rev, its recently had a full engine rebuild with forged pistons, everything is new including ecu, loom, injectors, sensors etc.. and has had many master mechanics pickled and would like opinions from people who know about fords so ive decided to try here oh and i was wondering if anyone else has come across this problem, cheers.

Liam.

P,S car is god damn curse

 

Is it running rich?

It's most likely a sensor issue.

Martin

 

not too sure, it isnt smoking and probably is a sensor issue but finding the right one lol but ive got a new crank sensor to fit so will try that

 

is your throttle body ok ,is the butterfly opening and closing .

have you got correct fuel pressure?

 

hmm havent checked fuel pressure will give that ago, and stale fuel may be partly to blame

 

Map sensor is by far the most likely option.
Another possibility is you have piped up the FPR backwards.

Regardless, 30mins at a specialist would probably sort it no problem.

 

at a guess cos aint seen what your car is doing but has it got the correct chip in the ecu for the spec your running?? and as above take it to a pro if all fails

 

when you say it won't rev, do you mean to say it won't do anything when you press the throttle or that it coughs and splutters when you try to rev it?

2 different things

 

TPS connected? That could be it.

Check the plug that's on the throttle body

 

it just dies when throttled, and has a new chip

 

Was it ok before the chip?

It's DEFINATELY not the TPS, that won't cause this.

 

its funny because when we brought it into the garage i work in, im only 19 but i did the engine re-build my self and i know its perfect, but once the car was back together, it started and was running lovely, and then a guy who was helping out who i work for accidentally crossed a spanner from the number one injector to the chassis, and it started running crap so we switched it off and it would never start again, but what we didn't realise is that it fried the ECU, but we didn't know this at the time, at closer inspection we found that number 1 injector was stuck open while cranking it, so we changed the injector and checked the others all squirting perfectly in order(this was after we changed the ECU, chip and rewired the loom that was melted together lol), still wouldn't start, so we checked the spark and it wasn't sparking, changed the spark plugs and still no spark, changed the distributor and the coil i think it was and got spark from it, did compression test also was fine and it started but now it wont rev, it just dies when you press the throttle, i really believe this car is cursed haha

 

set fire to mine like that with a wiring short leaving an injector open

my advice would be to not mess about and take it to a professional to sort

 

As said, look toward the MAP sensor AND you have the hoses plumbed properly, as well as checking all the connections, it's also not uncommon for things to be misconnected, i.e. phase and CPS connectors etc.

Martin