REULv3

My 99 Cherokee ran fine last night but when i woke up this morning it wouldn't start. It'll just keep trying to turn over. I replaced the CPS about 30 minutes ago with no luck of getting it started... Any help?

belvedere

Is it missing spark or fuel?

Daniel89

I sought of have same issue plz help ..

Parsnip

Ok. Time for the beat---lessons to begin.
First off, pull a plug and have a friend crank the motor while you hold the RUBBER BOOT of the spark plug, unless your a manly man and like that stuff...anyways ground it to something, the head for exapmle.

Do you have spark? If yes, carry on to make sure that a) when you turn the key the pump primes and b) you have proper fuel pressure, mwaured via a mechanical gauge.

Report back after both of these have been verified

REULv3

Well i just replaced the coil that runs to the distributor. Wouldn't turn over. It would just crank and crank again. Took the spark plug out to test if i have a spark and i got nothing. Not even a weak spark... So far I've replaced the CPS and the Coil pack. I took the cap off of the distributor to see if it was spinning on the inside and it was slowly, I don't know how fast it should be spinning. I've heard from one person that the O2 sensor could be the cause. It is throwing a code for the O2 but its been on since Sunday and it died on Wednesday morning. I plan on replacing the O2 sensor tomorrow.

Radi

It isn't the O2.

See if you have spark coming from the coil. Moving a plug wire over to the coil output terminal is one way to check.
Since you just replaced the coil and have the same symptoms, we'll assume the coil itself is OK for now...

If no spark at coil terminal, check for power to the coil connector with key 'on'.
If no power trace back through the ASD relay.

If you have power, check the other coil connector terminal with a test light. One end of test light on coil terminal, other end on ground. Light should flash while cranking. If light stays on steady there is no trigger pulse from the PCM. If light does not come on at all the coil winding is open or there is no power to it.

REULv3

Well just an update i checked one of my O2 sensors and one of he wire's before the plug that leads to the O2 sensor was broke in half. I fixed that wire and did an ecu reset. Now when the jeep cranks she actually stutters. She wants to start so bad! The battery is pretty drained from me cranking it for 4 days and not charging so in gonna see if i cant get it jumped and see if that works.

REULv3

Well now I have spark. Found out I have no pressure in the fuel line. Now im guessing its the fuel pump. Im gonna check and double check all of the grounds. Hopefully I can get it on the road soon.

phishermanjohn

Try turning the key to on and letting the pump run. Could be the check valve in the fuel pump and needs to regain prime. If that is it then just splice a check valve in line.

cherokeeyed

Check fuses and relays. If that 02 wire ground out it could have blown a fuse or relay.

DFlintstone

Parden me for jacking one or two posts REULv3. Chuck. Does that mean on a Renix one could put a light off where the "second yellow" Connected, and to ground and get a flash? Is the 99 that different? I'd think with the 5v wire from the puter' off it would not have a signal. Now the wire from the computer...

We just have the 4, power, puter', tack, n' ground. IIRC

Again pardon me Reulv3......Sounds like you are getten there!

Daniel89

jeep still not starting
I have a 1999 jeep Cherokee sport , recently it died , I sent too auto elecs it was cranking but no start , they said it might be a immobilizer problem and there was a fault ,I got it back not cranking , key symbol on dash , bus showing on odometer , and electric locking not working , I changed computer , immobilizer , and key barrel , symbol and no bus gone and doors work , but yet still not starting , I Also changed crank sensor on gear box , someone plz help its doing my head in .... :?:
hey ive got it cranking now ,we changed the neutral safety sensor ,it was stuffed we are getting spark to coil but not from coil onwards,it gets power or spark at coil at the start of trying too crank but doesnt stay .., any ideas on what could be stopping it continuing from coil,.any ideas.,

REULv3

I've tried to turn the key on and i don't even hear the fuel pump prime. I thought it was the relay so i just swapped it with a different one and still nothing. I tried to jump the fuel pump relay and only got a little click noise, still no noise of it priming. I've check every fuse and relay in the damn jeep and there fine. I'm gonna go back over every ground, fuse, possible problem the jeep could have and rent a fuel pressure gauge to test the fuel pump.

DFlintstone

I'm not your guy. Just learning my Renix. If I was looking at a 99 I might depress the deal there there on the schrader valve on the fuel rail, (like a tire stem), and see if it spurts fuel into the rag I'm holding there. No pump sound and no spurt ....doubt the gauge will help there.

Anyway not my business, that 99. You can have the codes read free at the auto parts. Writing them down and posting them might help someone figure it out.