Jeep Strokers

It runs OK until it goes from warmup to eh? Is your distributor correctly installed? You also should check the O2 with multi-meter.

You're not mentioning in this thread like you did on another forum that you made the distributor adjustable............

Do you have a wideband O2 sensor installed?

Being that it happens at idle it might be the IAC valve. If you keep your foot on it to keep the idle up how does it run then?

Should still start and run with all input sensers unplugged( except for m.a.p.) Big vacuum leak?

Ok I broke in the cam...now it just wants to idle high. Also during the break in I,noticed the fuel/air mix gauge read rich then slowly ideal then slowly into,lean after about 10 minutes in @ 15-2000 rpms

Here's my rough draft on indexing the distributor, taken from the FSM.




Remove the distributor cap and cut a "window" into the side of the distributor cap at the #1 spark plug wire post . The "window" should be large enough to allow easy visual inspection of the position of the distributor rotor at the #1 spark plug wire post. Reinstall the distributor cap.

Install a ¾” wrench or socket onto the vibration damper retaining bolt . Rotate the engine in a clockwise direction until the #1 cylinder is at top dead center. Align the timing mark on the vibration damper with the "0" degree mark on the front cover timing scale. The tip of the distributor rotor should be near the #1 spark plug wire post.

Disconnect the distributor electrical connection. Remove the distributor holddown clamp, holddown bolt and distributor. Remove the distributor cap and rotor.

Place the distributor housing upside down in a soft jaw vise. Scribe a line 1/2 inch from the end of the distributor locating tab. Cut the distributor locating tab at the scribed line with a saw.

Remove any burrs and metal filings from the distributor. Reinstall rotor.

If necessary, using a flat blade screwdriver, turn the oil pump gear drive shaft until the slot is slightly past the 11 o'clock position. The oil pump gear drive shaft is accessible through the distributor mounting bore in the engine block.

Visually align the modified locating tab area of the distributor housing with the holddown clamp bolt hole.

Turn the rotor to the 4 o'clock position.
Lower the distributor into the engine block until it seats. The rotor should now be very close to the 5 o'clock position.

Reinstall the distributor cap with the cutout "window". Rotate the distributor housing until the trailing edge of the distributor rotor tip is just departing from the #1 spark plug wire post terminal .

Reinstall the distributor holddown clamp and bolt.. Reinspect the position of the rotor to the #1 spark plug wire post to insure that it has not moved.

Install the new, distributor cap, reconnect the distributor electrical connections.

Revised 07/03/2012

Merged topics!

Huh?

grainofsalt wrote:It runs OK until it goes from warmup to eh? Is your distributor correctly installed? You also should check the O2 with multi-meter.

t
he o2 sensor WAS checked with a multimeter. And yes the distributor is correctly installed.

cruiser54 wrote:You're not mentioning in this thread like you did on another forum that you made the distributor adjustable............

in both this and the jeep forum I posted that the ears were cut off the distributor to make it "adjustable" due to the aftermarket cam installed....i think my phone screwed up and posted 2 threads on this forum which seems to have been joined together now by our friends in high places. Thank you!

SilverXJ wrote:Do you have a wideband O2 sensor installed?
Being that it happens at idle it might be the IAC valve. If you keep your foot on it to keep the idle up how does it run then?

The IAC ran great b4 I did the swap and I put the pintle on it to match the HO throttle body. Is there a way yo test it? Yes it runs with throttle but at idle stays high after I performed the cam break in. my thoughts might be,IAC as well at this point.

racing89 wrote:Should still start and run with all input sensers unplugged( except for m.a.p.) Big vacuum leak?

All vacuums are plugged or connected. The only huge vac leak I have is I giant hole about 62mm in the throttle body

You might wanna check your IAC (idle air control valve). The idle symptoms you describe are pretty common for one that is bad. Sometimes just a good cleaning will work.

Also you said your map sensor is plugged into the throttle body? I do not have a vacuum port on my throttle body (think it is a 96) but it is possible a vacuum port on a throttle body could be metered. MAP sensor line should be connected directly to manifold vacuum IMO.

I have a stroker in an 89 and have had no tuning issues at all except a recent bad IAC valve that made the idle unstable and caused the rig to die intermittently, particularly when coming to a stop from just off idle.

I agree with the person that said to unplug your MAP adjuster for diagnostic purposes.

What are you running for a fuel pump? The reason I ask is that later model Jeeps did not have a vacuum pull off on the fuel rail to return fuel to the tank it was done internaly in the tank. You make no mention of what was done for the fuel return.

gmakra wrote:What are you running for a fuel pump? The reason I ask is that later model Jeeps did not have a vacuum pull off on the fuel rail to return fuel to the tank it was done internaly in the tank. You make no mention of what was done for the fuel return.

Alrighty im back i apologize for the delay...been goin thru rough times with the misses lol.....so the fuel pump is the same one that was in the truck when i bought it. The fuel rail was exchanged with a uh 92 93? jeep cherokee's. The original fuel rail on the 89 had 2 ports on the fuel rail: one in the rear and one up front. The one up front had a vacuum line and regualtor and the one in the rear had just a line....The fuel rail i installed also had 2 lines both up front of the fuel rail and a vacuum pressure regualtor as well. Fuel deliver is good since i installed a clear filter inline i could see the fuel pump into the filter as i cycled the key a few times before its initial startup. The setup is as follows: The fuel input is from a 3/8 fuel line into the 3/8 port on the fuel rail and the return is through a 5/16 fuel line on the regualted port on the fuel rail.....i thought this may be odd but then convinced myself that if the return was restricted then it WOULD actually maintain fuel pressure in the regulator. So i left it at that...im goin to research a little more into this. I also added a new IAC a couple days ago. Removed the pintle and spacer and put on the wider pintle matching the HO throttle body. No change, minus the quicker response of the new IAC.

I seriously doubt that not breaking in the cam is causing the problems but you'll need to go through the break-in anyway.
Indexing the distributor will get the injector firing properly synched with the spark. I know you've tried it already but check it again using the procedure in http://www.angelfire.com/my/fan/dist_index.html (you can omit step 3).
As others have suggested, disconnect the MAP adjuster and leave the MAP sensor with the normal 5v input for now. Tap into the middle wire from the MAP sensor and monitor the voltage while the engine's idling. If you have good vacuum it should stay somewhere around 1.5-2.0v. If you have a gauge, check the idle vacuum in the intake manifold. With the Crane 753901 cam it should be near 17inHg.
An IAC issue will only cause problems at idle but won't affect overall engine performance. You could try disconnecting the IAC wiring harness, disconnect the battery for 10 minutes to reset the PCM, and see how well the engine idles without the IAC attached.

Cheromaniac wrote:I seriously doubt that not breaking in the cam is causing the problems but you'll need to go through the break-in anyway.
Indexing the distributor will get the injector firing properly synched with the spark. I know you've tried it already but check it again using the procedure in http://www.angelfire.com/my/fan/dist_index.html (you can omit step 3).
As others have suggested, disconnect the MAP adjuster and leave the MAP sensor with the normal 5v input for now. Tap into the middle wire from the MAP sensor and monitor the voltage while the engine's idling. If you have good vacuum it should stay somewhere around 1.5-2.0v. If you have a gauge, check the idle vacuum in the intake manifold. With the Crane 753901 cam it should be near 17inHg.
An IAC issue will only cause problems at idle but won't affect overall engine performance. You could try disconnecting the IAC wiring harness, disconnect the battery for 10 minutes to reset the PCM, and see how well the engine idles without the IAC attached.

Well the cam break-in has been performed...it did take me a little while to do so since the motor would shut off constantly but i did do it. The distributor.....yes sir....i WILL perform this step again today. Ya'll are being so helpful and it would be foolish of me to ignore. MAP adjuster.....i have not disconnected it but have adjusted the voltage back down to 5.0 volts and checked it while running to see if there is any fluctuation....there is none....do you whole heartedly reccommend me to ffully disconnect it and wire it back factory? I will also check that middle wire to ensure it has 1.5-2.0 volts at idle today. I do not have a vacuum gauge and i tried looking for one yesterday as well as a fuel pressure gauge but the autoparts store "did not have any". The IAC was replaced the other day and I have disconnected the harness in the past to see how it would operate....but i never reset the PCM as you have described. I will attempt that test today as well. I've also noticed an odd thing yesterday....i took a male spade connector and placed the metal side in between the throttle lever and the throttle stop on the throttle body, and started the vehicle....just to bring up the rpms a bit so i could have it run a little while....well the rpms stayed up, the IAC closed the hole(loud sucking noise disappeared) and the rpms stayed up around 1500....then after about 15 seconds the rpms dropped down to a rough idle and stayed there for 5 seconds and then abruptly stopped...so i cant even keep the rpms up at this point. Hmmmm.