Well I am working of fixing up a 89 Jeep Cherokee.

I am having some long crank issues with starting the Jeep. I timed my start times and it takes around 2.5 seconds on average to start Jeep, 4.0L I6. Now I know many will say fuel pump and the valve but I have just replaced mine as I had a fuel pressure issue.

The starting has gotten much better but still has a bit of a long start, as before the fuel pump was replaced it would crank on average 4.7 seconds I actually used a stop watch.

Now my Jeep run even better but I want to clear up this starting issue. Someone that is a mechanic that I kind of know thinks it could be the IAC but he has not checked it, he was at a store just getting out of his car when I was starting the Jeep he works at the shop I take my cars to occasionally anyway he thought that is what it was as he has had Jeeps with those issues in the shop before.

Now the IAC was something I was planning to replace anyway as my idle is all over the place, though I am working on some vacuum issues now and will fix those before replacing my IAC.

Now I have replaced my negative battery cable and a ground wire but could my positive battery cable be shot? I had a problem with the cable and planned to replace but parts store gave me the wrong cable so I just replaced the connector to the battery.

Also, before I forget I have also done a complete tune up also along with replacing the fuel pump, fuel filter, and negative battery cable.

Thank you for everyones help in advance.

 

You may need to Check/replace your CPS http://go.jeep-xj.info/HowtoCPSchange.htm There is a way to test the CPS but I forget the way to do it...Tj

 

Thanks for the posts...I have a similar issue...was considering replacing the fuel pump. But I only have the problem from a cold start. Usually, it takes 4-6 seconds to start on the first crank, but will start right up on the seconds crank.

 

Thank you for the responses. I just really want to get this thing figured out. Once I am done taking care of all things related to the vacuum I will move on to the idle and see if the IAC needs to be fixed.

By idleing all over the place I mean that while warm there are times it will idle at 750 RPM in gear as I have been told it should do but other times it will not. I could be driving it and come to some stop lights if there are 4 different stop lights it will idle at 4 different speeds once I come to a stop and wait at the light. The same hold true if I stop somewhere and put into park I could stop it and it may just idle at 4 different speeds for everytime I park the vehicle and leave it idleing.

 

OK I must have misunderstood your first post. It cant be the CPS if just the idle is not correct I would clen the IAC and throttle body out and check for vacuum leaks first...Tj

 

Ok thank you for your update. I've done the throttle body cleaning and now I'm on to fixing the vacuum leak problems. The vacuum would be fixed if I was sent the CORRECT parts.

I do have a long crank problem also so that mechanic guy I kind of know is right with the IAC giving me problems?

 

Around 2.5 seconds is actually pretty quick for a renix motor.
Its not made to start right up, like a chrysler injected engine.
A renix engine must find #1 TDC and hit 300 rpm before it will send fuel and spark.
Mine usually takes about 5 seconds to start.

 

Hmmm that is good to know. So I fix the vacuum problems and replace the IAC and I should be good to go.

 

Yeah, Ill take a video later, just to reassure you and because I like making videos...

lol

 

The 300 RPM thing is interesting because I was going to mention that when I turn the igntion to on I never hear the fuel pump buzzing or making any kind of noise. So I guess these Renix engines are just a different breed. I love my Jeep though and literally find any reason to drive around. I have only had it about a month though.

 

The fastest its started in a while...

 

I found that mine was taking awhile to start when raining or humid. I found the problem while replacing motor mounts. The wires to the sensor in the dist. were rubbing on my pass. side motor mount and grounding out...... worth a look.

 

They always take awhile to start. Its just the way they are. If you dont have any running/driving issues I would not worry, if it starts to take longer than 4.5 seconds than I would look into the battery first, then start looking at clogged injectors, dirty TB , then look at sensors. Always start cheap first. General rule of thumb.
1. Free stuff.
2. Cheap stuff
3. expensive stuff.
I hate step three.

 

Thanks everyone for the help looks like my "problem" is not a problem at all. Well I will check the vacuum lines and once I finally get the correct vacuum reservoir in I will replace that then the IAC and should be good to go for awhile.

 

yeah, 3 seconds for me hot or cold. no problems I could find, I finally said its normal, and got used to it.