flexyxj
'92 4.0 misses thoughout rpm range.I installed plugs,cap,rotor,wires,and a new fuel filter.The local stealership told me to try 2 bottles of Gumout fuel injector cleaner and top off the tank.It does not throw a code.By process of elimination,how can I figure out which injector is the culprit?
mrtazwrench
pre obd 2, around 96 will not set misfire codes. if you can find someone that has a motor vac injector cleaner machine, that is much better than the in the tank stuff. :t: trying to locate the missing cyl, you can either pull plug wires one at a time with a good insulated plug wire plyers or, pull injector wires one at a time.
flexyxj
I tried the plug wire deal and still couldn't figure out which one was misfiring.After getting juiced a couple of times I decided that wasn't a good plan.This motovac deal ...how spendy of a deal is that?
mrtazwrench
i'm not sure what my boss charges, will vary place to place ofcourse, but since i have one at work i get to use it for the cost of the cleaning solution, the other thing that has been helping on the g.m. injectors is techron cleaner, that goes in the tank, as far as the motor vac, just check to see if any shops in your area have one, it hooks into the fuel rail, bypassing the fuel in the tank, the rail gets flushed with the vehicle off for about 10 minutes, i usually use some of the solution to clean the throtle body while it flushes, then the engine is run on the machine for 30 minutes, and i usually back the pressure onthe machine off as much as i can and still have the engine run, this causes more injector on time alowing more cleaner to flow through everything.
flexyxj
I'll keep you posted.I'm not sure what I'm going to do at this point.I've got some noisy lifters too.I'm begining to wonder, if one is collapsed.I'm not getting any backfiring or popping out the exhaust like you would if there was a burnt valve or a valve not seating.I just don't know. :(:Thanks for taking the time to reply.Pat
BREK
one of my tech's here at the stealership told me to have you put an ohm meter on each injector and they should be between 13-15 ohms
youdidwhat
Try 2 cans of "Sea Foam" system cleaner.. it works as opposed to that other Cr%p
it works slowly. I.E. it will get worse the first day and the longer it is in there doingits thing the better your rig will run.
Just my $.02
flexyxj
Thanks for all the input guys.It turns out I've got 2 dead cyls. with 45-50 psi compression.Cyls #2 and #3,so probably a bad headgasket.I'm not sure how much more time and $$ I care to put into this '92xj. :smile:
mrtazwrench
that was the place to start, making sure the state of your basic mechanical issues, i was under the asumption that this had already been done. :-|
flexyxj
I don't have a compression tester and assumed that wasn't the issue.I didn't think that it would come up lame the way it did.It ran good going to work and started missing on the way home.When I changed the plugs,and found the electrodes down even with the insulators,I thought it was an ignition issue for sure.I appreciate you taking the time to give me some input.
mrtazwrench
kind of a bummer that it will need a tear down to fix it. #-o
flexyxj
:(: :(:
youdidwhat
flexyxj
'88 is the Renix 4.0 and wouldn't be compatible with my '92 4.0HO,unless,it came with the complete wiring harness,computer,and etc.I appreciate the thought.I may decide to part it out.I'm sitting on the fence and will decide in the next week or so. 111!!!
