Adrian95XJ

I have a 95 Cherokee Sport with the 4.0 automatic and 4x4. I recently replaced the coolant temp sensor, CPS, Cam position sensor, temp gauge sender, dist cap, rotor, spark plugs and has other new sensors for about a year now like the TPS and plug wires. It starts rough then dies unless I step on the gas until it runs fine when warm.

I realized that the check engine light doesn't come on when I put the key into the ignition position before starting. But it is intermittently. The pump doesn't kick in if the check engine light is off.

I have ran out of ideas. Could it be a bad PCM??

Idunno

Idle Air Controller. It's that small device on the intake adjacent to the TPS. Mine did the same thing and it turned out to be a failed IAC. It acts like the "choke" used to in the days prior to all things computer controlled. It's supposed to allow a richer mixture to keep the engine running when cold and then reposition when warm. Chances are cleaning it won't do anything except waste time. I replaced it and got back my normal cold idle.

Adrian95XJ

It could be that since I didn't replace it and I tested the resistance which they are within the range. But she sputters as if the ignition was turning on and off even when I rev the engine to 2k rpms. Each time it sputters the engine light comes on. It's if it was losing power to the PCM since I replaced everything ignition related.

Roler

Could be a few things.
have you checked for codes yet though?

What do you mean with "the pump doesn't kick in when the check engine light is off"?

Adrian95XJ

The only codes I get is 12 and 13. 12 being the battery being disconnected and 13 is the MAP sensor since I messed with the vacuum line and hooked it back up since it made a change with the AFR. I meant that when I switch the key into ignition before cranking the engine, the light doesn't come on. If I try to start it, she doesn't fire and I keep trying until eventually it lights up and the fuel pump kicks in.

I gotta wait for s few seconds as if I had a diesel waiting for the glow plugs which it doesn't make sense. This only happens when I try to start the engine when cold in the morning and when I park somewhere and a couple of hours pass.

agreen

Have you cleaned the ground points on this?

Adrian95XJ

After I cleaned the grounds and disconnected the plug for the PCM with the battery disconnected it started the issue. Before that it only used to run rich on startup. Now she just starts whenever it feels like it.

Roler

And did you replace all the parts mentioned in post #1 after this issue occured or before?

Adrian95XJ

I replaced them before it occurred. The spark plugs were looking nasty and most sensors the connectors broke off.

Dave51

Test (check resistance) and clean the fuel injectors. Could be leaking down.

agreen

Put the old TPS back on and try it.

RocketMouse

yeah those things are notoriously hit or miss right out of the box..... unfortunately.

Adrian95XJ

Unfortunately, I returned the old CPS to the auto parts store and that part number was discontinued.

RocketMouse

yeah the CPS and TPS sensors are just not that well made for some reason. Some will work right out of the box... others fail a few months later...