1987 cherokee issuse
Thread Starter
Junior Member
Joined: Sep 2011
Posts: 36
Likes: 0
Year: 1987
Model: Cherokee
Engine: 4.0
thank you sir!!!! you have helped me out a s*** ton!!!! i know what a MAP sensor is and does i just wanted a 2nd oppinion. this is my first jeep iv owned. im use to DSMs lol
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Thread Starter
Junior Member
Joined: Sep 2011
Posts: 36
Likes: 0
Year: 1987
Model: Cherokee
Engine: 4.0
so i finally got over being sick and had time to fix the MAP sensor. it does run a bit better.
1- still runs rich and i think the gas is mixing with the oil....
i cant really tell but the oils is thinning bad smells a litlle bit like gas.
2-it still stalls out from time to time...
3-just today it started to not want to start... it cranks over tried to fire but wont. let it sit a bit then itll fire and start... starter is fine, the fuel line does get pressure so maybe fuel filter???? or fuelp pump starting to go out?
1- still runs rich and i think the gas is mixing with the oil....
i cant really tell but the oils is thinning bad smells a litlle bit like gas.
2-it still stalls out from time to time...
3-just today it started to not want to start... it cranks over tried to fire but wont. let it sit a bit then itll fire and start... starter is fine, the fuel line does get pressure so maybe fuel filter???? or fuelp pump starting to go out?
Ronnie, Did you ever get a stock air box? That CAI could be causing some problems if the valve cover breathers are not hooked up. On my F150 the PCV valve was stuck closed, and it would idle low and surge. And it would also smoke when I started it.
Just one more thing to look at.
Just one more thing to look at.
Thread Starter
Junior Member
Joined: Sep 2011
Posts: 36
Likes: 0
Year: 1987
Model: Cherokee
Engine: 4.0
i havent yet. i was actully talking about that to a friend right after you called me but i figured away around the stock air box... im orderin two new gromets tonight then cutting the one stock brocken hose i have for both valve cover breathers and hooking them up to the intake i have now... and yes i have figured out thats why it smokes.....
and yes i do have a meter.
im looking on rockauto.com right now for the CPS were do i look under???
and dale what your explaining with your f150 is pretty much what its been doing... LOW idle, surges a little bit, and you know the rest of the BS
and yes i do have a meter.
im looking on rockauto.com right now for the CPS were do i look under???
and dale what your explaining with your f150 is pretty much what its been doing... LOW idle, surges a little bit, and you know the rest of the BS
http://www.rockauto.com/catalog/raframecatalog.php
Not sure if that works with rockauto. But it's in the Ignition section.
Not sure if that works with rockauto. But it's in the Ignition section.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
There is a test cruiser has for the cps. Un-plug it and probe the two wires to the sensor with the meter on the AC scale and have someone crank it. .5 volts he says is good. I guess .4 could be OK, but .35 and lower is likely gonna be a problem. Furthermore there is a process to drill and get the coil closer which ups the output that I need to see better.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
There is a test cruiser has for the cps. Un-plug it and probe the two wires to the sensor with the meter on the AC scale and have someone crank it. .5 volts he says is good. I guess .4 could be OK, but .35 and lower is likely gonna be a problem. Furthermore there is a process to drill and get the coil closer which ups the output that I need to see better.
While tightening the attaching bolts, push down on the cPS.
And yes, .35 or lower volts from the CPS is an area that can cause intermittent no-starts.
Keep in mind that if you have an 87 or 88 Cherokee or Comanche with the C101 connector, you can have good CPS voltage but there may be too much resistance in the C101. Clean your C101 connectors as a matter of course. Almost every important signal between your sensors and ECU travel through the C101!!!
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
I just put "c101 connector" in Bing. 3rd one down shows a big mess/plugs of wires directly above the brake vac booster.
....Ah...Cruiser, now I get it. Wallowing the holes lets you move it DOWN to be closer. Couldn't figure how larger holes would make it closer IN. So the downward pressure there is crucial. THANKS!(again).
....Ah...Cruiser, now I get it. Wallowing the holes lets you move it DOWN to be closer. Couldn't figure how larger holes would make it closer IN. So the downward pressure there is crucial. THANKS!(again).
Last edited by DFlintstone; Oct 21, 2011 at 01:56 PM.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
It's mounted on the firewall above the brake booster. It's a junction of the engine fuel injection harness with the chassis ECU harness. There is a bolt in the center holding the halves together.
Unbolt the halves. Pick out all the black tar crap with a pocket screwdriver or the like. After that spray out both halves with a good electronics cleaner or even brake cleaner. After it's real clean, take a small pick and tweak the female connectors in the harness so they'll grasp the pins more tightly. Apply dielectric grease to the two halves and bolt back together.
Unbolt the halves. Pick out all the black tar crap with a pocket screwdriver or the like. After that spray out both halves with a good electronics cleaner or even brake cleaner. After it's real clean, take a small pick and tweak the female connectors in the harness so they'll grasp the pins more tightly. Apply dielectric grease to the two halves and bolt back together.


