mustfan

So my 89 fox lx has been sitting for a while now, and i just cant seem to find the problem, heres a checklist of what ive put on new
- distributor
- rotor
- tfi module
- coil pack
- iac
- solenoid

I thinks thats all ive done so far, well it does have spark, it does get good fuel pressure 36 psi i checked that out with the tester, it does get spark because i put a shirt with fuel on throttle body and it starts for a bit, im thinkin the ecm??? But not sure thats my best guess, any ideas why injectors arent spraying fuel to spark plugs? Plz help any help would really b appreciated thanks for checking this thread out btw

dawson1112

I know its going to sound silly, but check the return voltage of your throttle position sensor. If the ecm thinks your throttle is in the WOT position it will cut the injectors off during cranking. You can test this between the black and green wires of tps harness, key on engine off. You are only supposed to see some where between .7-.9 volts at idle position. This voltage increases as the throttle is opened. If you probe the green and black wires and you get any thing above 4-5 volts then either the tps is faulty or there is a short some where in that circuit.


Also inspect the salt and pepper connectors on the rear of the engine, the 2 big plugs one is white and one is black/or grey. Make sure there is no corrosion and that they are making good contact.

88 orangepeel notch

Here's a good read and something you should bookmark

http://sbftech.com/index.php?topic=588.0

It's helped me more than once...

mjr46

have you put a noid light on the inj harness and see if they are pulsing?

mustfan

If i had found this earlier it wouldve helped me alot im saving this link just in case in the future thanks for the link

mustfan

I actually found the problem, it was the ecm the whole time, i replaced the old with the new and it turns on now the ecm came from mexico i was like wow wtf awesome, but now the problem is that its idling low wanting turn off so i have to keep pressing on the gas 😕 but at least it starts right, im one step closer

dawson1112

Whats your base timing set at with spout out? If thats good , look at performing a base idle reset. http://www.muscularmustangs.com/idlereset.php