New Comanche Owner, rough idle.

[morgib]

A few weeks ago I purchased a 1987, Auto, 4x2, 4.0L. It was located about 2 hours from where I live, so I drove it back and didn't really noticed any engine issues on the drive home. The only thing I noticed was a lot more play in the steering wheel when going left compared to going right. Last week I went and did a tune up on it.

 

While doing the tune up, I found out that the PO had replaced the engine with a 1990 engine and it looks like he had bypassed some of the emissions for the vehicle since he lived out in the country. Now that everything is connected back (as far as I can tell it's correct), there is a very rough idle, sometimes it almost seems like it's going to stall.

 

Now one of the things could be the vacuum tubes hooked up properly and I think I have them set up properly (but not 100% sure). One of the other things that was brought up, by a friend, was the ECU. Not exactly sure if the previous owner changed out the ECU or not. Would I need the 1990 ECU for an engine swap?

 

One of the other issues that I'm having is the wiring. Which I'll have to work at later, but the guy did some of his own splicing and didn't exactly do it in the best possible way. I did buy another wiring harness, so hopefully I can get that solved.

 

Tune Up:

Distributor Cap/Rotor

Spark Plugs

Ignition Wires

Injectors

Air filter

Exhaust manifold (old one cracked)

Serpentine Belt

Valve cover gasket

Battery

Thermostat

EGR valve

Oxygen sensor

Replaced various hoses

 

Any help on this would be greatly appreciated!

 

Morgan

[btm24]

try the idle air control valve :thumbsup:

 

Brandon