88' manual
1st off cruiser tips done.

2nd off newer:
IAC(rockauto)
Distributor Cap(napa)
Plugs and wires (Napa wires NTK plugs)
upgraded and clean injectors(less than a year old)
Cleaned throttle body/butterfly valve
Newer o2 sensor(not bosch) and catalytic converter(you suck CA emissions)

Other than that everything looks or tests good sensor wise and is stock.

Symptoms:
low rpms have a misfire and and occasional high idle upon start but goes down within 10 seconds and misifre goes away and runs ok when rpms go above maybe 1700(no tach)
moving slow in 1st gear with as little gas as possible misfires as well but goes away when rpms go up with gas

Any ideas or help appreciated.

 

Here's Cruiser's link. > https://www.cherokeeforum.com/f51/cru...x-tips-153657/

It's my bet you want to start with doing 1-5. (maybe #27).

That link and some misk info is in the link in my sig. Btw. My "pesky" idle trouble seems to have been the connector right in the IAC...took me a while to figure that one out!

 

ill check the connector to iac but first thing i said was ALL of Cruisers tips are done. thanks though

 

Please describe the "misfire". Is it a vibration at low RPM? If you put your finger to the throttle just enough to raise RPM, does the vibration go away?

 

Did you clean the c101 or bypass it?

Have you checked your fuel pressure?

 

The engine drops power for less than a second then when it regains it on the next cylinder it shakes the car like at startup kind of. Hard to explain exactly. It is very exact the timing as if from one cylinder on each pass.


And I bypassed the c101 about a year ago. Cut and soldered each wire carefully(some previous background electrical work).


I have not checked fuel pressure yet.


It seems like a distributer thing because when it gets a higher rpm it goes away but I know many things affect or control the speed of the distributor.


I will try to get my hands on a fuel pressure gauge today or tomorrow.

 

Have you wiggled the distributor shaft side to side?

 

i have not touched the distributor in any way lately. should i? or should it move? sorry im super busy right now with school so im having hard time finding time to work on it.

ugh, i swear i can plan on this thing breaking in some way during the 1st week of school every time. its right when im most busy right after i sat around with tons of free time for a month.

 

Take the cap off and see if the shaft the rotor sits on wiggles from side to side.

 

So the grey part that just sits on top with the blade has a microscopic amount of play. I would guess the amount of play is the same as the thickness of a second hand on an analog watch.

The brown plate(slight surface rust?) moves a little rotationally but not side to side. I grabbed it and was able to spin a tiny bit but not move side to side.

I tried to wiggle side to side the entire distributor as well as each piece I could touch. It all seemed very secure and would not move except for forementioned parts.

 

That's all good then.

 

any other ideas? I have some free time tomorrow so I will be double and triple checking some stuff and sensors and hopefully can get my hands on a vacuum gauge too.

 

You did Tip 13,right?

 

Yeah I did it a while back and I checked to make sure the rotor didn't move a couple days ago.

 

Time to do the wiggle test on injector plugs and plug wires. With it running.