Jayraud

I recently installed a different engine (1986) Gt block, gt40 heads, bored .030 over with stage 1 trick flow cam a9p ecu. The difference is, I put this into my 1989 f-150 4x4. Now I can't get it to idle smooth at all. Also, once I put it in drive and hold the brake, it surges forward with the idle. I can't find anything wrong. Any ideas would help me out. Thanks

mjr46

was your truck mass air equipped before?? and if not and a proper mass air conversion was not done that may be the issue, you can't just plug a mass air ecm into a Speed density harness and expect it to work.....or is the truck speed density currently and you figured plugging a mass air ecm would work??...........you have by far have not provided enough info for anyone here to properly guess what your issue could be since you are doing a swap/conversion between different models

Jayraud

Sorry for the lack of info. It's been quite a project to undertake. I did do the maf conversion. When I first start up the truck cold. It cranks over and revs about 3000 rpm (no rpm tach), then it dies. I have to keep cranking it over 3-4 times giving it gas for it to actually idle. Once it idles (not great), I put the truck into drive, while holding the brake, the truck wants to surge forward and the idle slightly revs with the surging. Any ideas?

mjr46

check for vaccum leaks and make sure that your map sensor is no still plugged into a vaccum source....it becomes a BAP on maf vehicles

Jayraud

Map sensor has been changed. I ran a code reader on it and it says my throttle position sensor signal is out of range. I've been watching several videos on setting a TPS and understand the voltage on the green wire should be from .75-.95 volts. I am getting 60-70 volts...brand new tps bad??? something is WAY wrong...

bluebeastsrt

Check for vacuum leaks before anything else. Elimanate the likely stuff before you start chasing electrical gremlins.

mjr46

up to 1.0 vdc is acceptable

Jayraud

I have checked vacuum leaks multiple times. I had to plug the majority of the ports in the intake.