PeterPerez1982

So I have a 1990 Cherokee and I have had nothing but starting problems- this is probably a common issue, so I've heard, but I have replaced the battery, as well as the battery terminals (they were rusted and acid build-up), and now I just replaced the starter because a couple of mornings ago, the car would not turn over.
It would crank, but not turn. I googled it and figured it may be the starter- so I hammered the starter just to see if the google findings were correct and indeed, the starter was stuck and once I banged it I was able to start her up!
Here's teh thing... I have a rebuilt starter and I still hear the crank, but it takes a while for it to fire up and start, maybe after a few seconds (5-10 seconds) after cranking it.
is it possible it could be the ignition switch?

Please advise.

scottmphoto

It could be your fuel pump. Also, there's a check valve that is known to go out. Try the "poor man's prime." Basically, turn you key from "off" to "on" 3-4 time without actually starting it. This lets the fuel pump build up pressure. Then after "priming" it, try to crank it. You should also get a fuel pressure gauge and test the fuel pressure. Most auto parts stores will have one in their "load a tool." Your fuel filter could be clogged as well. Always start with the simple and cheap things first before you start throwing money at it.
Also, it might be the dreaded CPS issue. Get a multi-meter and test the CPS.

Parsnip

As in while cranking it takes 5-10 seconds to fire? That's common on renix models. Cruiser will probably be by soon to correct me, but I believe it has to do with the Cps generating signal to the coil to actually fire the plugs, just takes a few seconds for the flywheel speed to allow ot to fire

PeterPerez1982

Thanks guys, it seems you may be right and I will have the fuel pump checked out- also about that common CPS issue.

I appreciate your advice.

JackJare9455

i have heard of a blown diaphragm in the fuel pressure regulator causing long start issues... usually pulling the vacuum hose going into the top and looking for fuel can diagnose that pretty quick..

freegdr

Renix ecms require a certain rpm to be reached b4 a signal is sent to apply spark to start...

cruiser54

Correct.

That said, if it were my newly acquired 1990 Renix Jeep, I would click on the pink link in my signature below and perform the procedures outlined in posts 1, 3, 4, 5, and 7 before doing anything else.

Peter, have you replaced the plugs, wires, rotor and cap? They're due every 30,000 miles.

A good throttle body cleaning (post 11) is good along with checking the intake manifold bolts for tightness and making sure all the vacuum lines are in good shape.