4.6L "Modified Poor man's" stroker

[wjtom]

One of the other 2 wires should be the ground wire but one of them should have read between .5 and 1.0 volt.You are checking it plugged into the tps and backprobing the wires right?Try this with the key on and engine off go from closed to wide open throttle and see if you get a reading on either of the other two wires.The signal wire should read from about .5 closed to 5 volts open throttle.If the tps is bad it may start showing a reading when the throttle is opened.

[Radioactivexj]

Well the IAC and TPS tested within spec. i'm starting to think it's a misfire issue because when you try to accelerate it stumbles. I checked plug wires, spark plugs, distributor is set perfectly. I'm almost tempted to install the stock injectors and see if that fixes my issue. I'm just really needing to get this thing going so I can start daily driving and wheeling it. Can anyone help? The idle varies from 800-1100 back and forth and it just sounds rough. Any ideas?

[akadeutsch]

If you are looking at a misfire you have one of three problems.
Bad compression
Bad spark
or
Bad fuel.
I think you are on the right track checking the injectors. Putting the stockers back in should not take too long and I have heard that they work fine in our strokers until about 4,000 revs anyways. Good Luck

[akadeutsch]

Any word on the cause of the mis?

[Radioactivexj]

I've got a guy checking on it for me. I haven't heard anything from him yet but its supposed to be done by this week so as soon as he lets me know what it is i'll be sure to let you all know.

[irontom]

Hi!

I had to register to post this. I don't have a stroker yet, but I am reading up on it for the past year, preparing myself to finally pull the trigger. Just a suggestion, but I did not see any mention of the MAP sensor in any of your posts. Did you check it? I read that you need to adjust the MAP sensor voltage in some cases to make a stroker run and idle correctly. Just my 2c.

[Radioactivexj]

Well my thoughts are that its either misfiring or possibly a timing issue. A map adjuster will not help if it doesnt run right in the first place. Maybe eventually when I get her running smoothly and have a wideband O2 sensor I may add a map adjuster for fuel adjustment in closed loop.

[irontom]

MAP sensor errors cause misfire and rough idle in general. Might be a cheap thing to test vefore throwing money at it.

Your problem might not even be stroker related. I saw similar problems in Jeeps that were standing around for a longer time.

- TPS malfunction
- MAP malfunction
- IAC malfunction
- rotten vacuum cables
- almost dead battery

All those cause poor idle, misfire in some cases, and general drivability issues.

Those are easy to check before throwing money at it.

[SilverXJ]

Maybe eventually when I get her running smoothly and have a wideband O2 sensor I may add a map adjuster for fuel adjustment in closed loop.

MAP adjuster won't alter the AFR in closed loop.

What injectors are you running BTW?

[Radioactivexj]

I must have gotten confused when reading about the adjuster in obdII vehichles. I'm running the neon 703 injectors. I've also researched and seen similar symptoms from clogged injectors. I soaked them in seafoam for a few days before I installed them because I was recommended to do so to keep them clean so i'm not sure.

[SilverXJ]

Where did the injector come from?

[Radioactivexj]

I got them with replaced pintle caps, micro filters, and o-rings. They were supposed to be cleaned also. I bought them from XJwonders on Jeep cherokee forum.

[Radioactivexj]

Well somewhat of an update. I talked to the mechanic I had looking at the jeep and just as I had guessed the timing was off so it had either been set wrong by our guy at the machine shop or the timing jumped. So he's ordering a new timing set and chain to install and he would let us know when he got her running smooth.

[beiwulf]

ouch… more cost of doing it a second time. That is a bummer and can relate. Best of luck and hope that is what solves the issue for you. One of the other things I read about is the crank position sensor sometimes causing some issues. It's been awhile since i have read your whole thread so not sure if that applies here brother.

Brian

[Radioactivexj]

Yeah very true. We did replace the crank position sensor with a new one so it should be alright. But I hope it solves the issue too. I guess we'll see after he replaces the timing set.