cherokee77

The same way you check at the wire. Just stick a screwdriver in the coil wire and ground against motor or pull a plug and put it in coil wire and ground.

The injectors will pulse as you are turning it over, you need a noid light or a volt meter to check at the plug. If you dont have pulse that would point at CPS. I doubt that is your problem though.

I would start with coil if you checked all grounds. , there about 50 bucks new. Also go through all the connector plugs and clean them.

Shade133

well i honestly cant think of anything else that could be wrong.

let us know if that fixes it!

bubbajohn95

i have a 89, mine would crank and no start, found if i unplugged the MAP sensor and plugged it back in it would start, don't know if you have the same problem but worth a shot.

Mr. Clean

#1, I am getting fuel at the injector rail, not sure if they are pulsing.
#2, Checking it at the spark plug, not a very strong looking spark.
#3, The CPS has 237.7 ohms at the plug, did not remove it from the car.
#4, the grounds behind the oil dip. where very greasy and loose, I took care of that. The ground at the back of the head is tight.

Shade133

did it fix the issue?

Mr. Clean

Where do you get a NOID light???? Or, what is the best way to check with a multi meter?

Mr. Clean

Where is the MAP sensor???

Shade133

directly center of the engine compartment on the firewall behind the engine. has a vacuum hose going to it and a plug.

map sensor is a possibility.

Mr. Clean

What does the MAP sensor do??

Shade133

The MAP sensor (MANIFOLD ABSOLUTE PRESSURE) changes voltage or frequency as intake manifold pressure changes (air flow increases or decreases). The engine's computer uses the reading to advance or retard engine timing. On older, non-fuel injected engines the vacuum advance on the distributor did basically the same thing.

The MAP sensor also works with other sensors on the Jeep engine, specifically the Throttle Position Sensor (on the throttle body) and Crank Position Sensor (on the transmission bell housing) to control other fuel flow and ignition timing functions.

If you're having problems with the MAP sensor, or are getting a Check Engine light and code for the MAP sensor keep in mind that other problems may cause that error code.

Bad vacuum hoses, vacuum leaks, bad EGR valves, intake manifold leaks, clogged air filter can all affect the MAP. sensor.

Also, if you have done any mods to the engine, especially intake, exhaust and ignition mods you may get an error code for the MAP or incorrect reading and a resulting loss in power or increased fuel usage.

The link below is a good write-up specific to the Cherokee MAP and how to make an adjustable MAP.
Source(s):

http://go.jeep-xj.info/HowtoMAPsensor.ht…

cherokee77

You get a Noid light at autoparts store for about 5 bucks.
To use a multi meter you really need a analog multi meter because the pulse you will see at injector is minimal. You can also try putting a screwdriver on injector then putting your ear on screwdriver . You should hear a click.

But like I said I dont think this is your problem because you have some spark.

bubbajohn95

i ended up spraying some electrical contact cleaner in the plug and haven't had an issue sense

Mr. Clean

We will be changing it out tomorrow, will post up after the change out.

Shade133

corrosion is the devil but its the most common problem.

bubbajohn95

either corrosion or loose contact either way its not a good thing!