Rough Idle

The other day i put some new 5.0L Mustang Injectors in the comanche hoping to improve the performance. After i installed the injectors and put everything back together i started it up. It immediately started running rough as if i had just put a cam in. I ran it for a while like this thinking it would solve the problem but it didn't. The whole time the truck ran really rich and would stall at stop lights/ signs. Since it didn't solve itself i switched back to the stock injectors thinking that would work, but it once again didn't work. It runs a little better but the idle is still rough and it feels/ sounds like its running on 5 out of 6 cylinders. I check the connections on the injectors, the spark plugs, wires, cap, rotor, and distributor and there didn't seem to be any problem with any of them. I have a 1987 Comanche with the 4.0L I6. Any ideas?

check the vacuum line going from the fpr to that module on the firewall and make sure its plugged in good and no leaks

Sounds like a bad o-2 sensor.

What Ford injectors?

Did you knock the vacuum line off the throttle body/MAP sensor?

joe_peters said:

What Ford injectors?

Did you knock the vacuum line off the throttle body/MAP sensor?

Click to expand...

this^^^ is what i meant

Damn you guys are good. I went over everything again this afternoon and it ended up being the vacuum line from the MAP sensor to the TB. It wasnt in the right hole on the TB end. Thanks for the help though. Im glad it wasn't something huge.

Glad you got it.

I've heard of people using the Ford injectors as well as LT1 injectors. Any advantage one way or the other? How many pounds are your 5.0 injectors?

There is a terrific post floating around here somewhere with facts/figures and a lot of work in. It also mentions using Neon injectors as a possible better performing alternative to the Ford injectors. See Rainman's posts here: http://www.naxja.org/forum/showthread.php?t=1027854&highlight=neon+injectors