Tech Support banner

Status
Not open for further replies.
1 - 2 of 2 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter #1
94 dodge caravan, 3.0 L engine idles rough, pull plug wire # 3 makes NO changes. switched injectors, can hear them snap when plugged in , not when unplugged. good compression, no blow-by from crankcase. valves have full travel. good spark and runs great at 65 up a steep hill. starts very hard when cold, then idles rough even warmed up, but unplugging #3 wire /or/ injector wire makes no difference at all ? all other wires make it bog severely when unplugged. its as though #3 cylinder is possibly firing wayyyy late. firing order is right, plug looks like its been firing a decent not too rich or lean burn. when idling pulling plug wire or injector wire makes no difference at all? driving me crazy trying to figure it out, no error codes and has new throttle resistor sensor, and o2 sensor. help!!!! why? [email protected]
 

·
Registered
Joined
·
2,290 Posts
If the problem is with a single cylinder, my guesses would be:

A vacuum leak near this cylinder, from the intake manifold or a vacuum hose. Try spraying some carb cleaner around the intake manifold junction and see what happens, if the engine RPM picks up and smooths out, then you are heading in the correct direction. The cold hard start also spells of vacuum leak, IMHO!

Possibly a plug wire or ignition coil, but I do not know the exact ignition configuration of this engine. Does this vehicle have 3 seperate ignition coils? You might be able to swap some things around to rule this out? This would be more unlikely as you indicate the problem is more at starting and idle.

You seem to rule out an engine machanical problem claiming the valves have full travel and the compression is good.

JamesO
 
1 - 2 of 2 Posts
Status
Not open for further replies.
Top