Does a 97 JGC have a TCU?

sputtered home, parked

while, I ran the tank out, and looked

Woodsy did pass the time by typing:

Yep

Bad #1 injector possible or bad ground. An engine analyzer hooked to the injectors will tell for certain. Find a better shop that can do an injector leak-down test ($65 or so). That will tell you for certain if those injectors are stuck. You could also get them to run a motorvac on it.

(expect that to cost about $120) themotorvac runs high strength cleaner through the rail and cleans the wholesystem (runs for about 20-30 min).

I would tend to believe the dealership mechanic your dealing with is a moron.

And we all know replacing $bigbuck parts are cheaper than tracking wires even if the wire remains broken. ;)

Went through this once with a "new" mechanic. Went all over the ABS system and couldn't find the fault. Till the greybeard came by and muttered that we should clean the connector and stop f--king around and taking up garage space. :) I couldn't get angry since I was out there trying to figure it out myself even though the obvious was glaring right into my face.

You got a tank of crapoline that might have clogged your filter and plugged the injector. Have you poured out any gas into a container?

If it is crapoline you should contact the gas station. Some times they will pay the damages. (A local Sinclair paid for a friends BMW after he let the tanks get so low they sucked muck) ..long story, happy ending..

sputtered home, parked

while, I ran the tank out, and looked

Thank you, Bill. This short reply will be followed up, later today. Off to the dealer.

Prior to dropping it off, I jumpered block to chassis, block to battery, chassis to battery with jumper cables, it made no difference. I had also pulled and reinstalled all the connectors that I could find.

confirmed by the statement "its opening day, the experianced tech went hunting"

no on the gas, I had let it run out,with can in back, hoping it would kill it or fix it. did neither. The injector cleaner "treats 32 gallons" in 2 gallons of gas did make it run great the next day, for about 40 miles, till I filled it up again.

Cheap gas, not a lot of hope on this note, from the reservation.

Then again, if it runs great, and has not had the #1 injector replaces, it was in the wiring. (can injectors be cleaned after they have failed?)

Thanks again, off to work and the dealership.

Frank

Woodsy did pass the time by typing:

Depends on the failure. But usually when you disconnect one injector and nothing changes that indicates it's clogged. It is possible for a clog to dissolve.

good luck.

My guess is you either got a water mix or a diesel mix instead of gasoline. Someone could have poured some diesel into the station's big tank or a flood/rain with the top loose or off the tank.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Woodsy proclaimed:

Yes, but I'm trying to think how it could cause rough idle unless it locked up everything.

Crank position sensor, dirty throttle body in that order?

Can't imagine why a general diagnosis of the modules are not communicating with each other and a mechanic with a pulse would be all that difficult to troubleshoot.

sputtered home, parked

while, I ran the tank out, and looked

sputtered home, parked

while, I ran the tank out, and looked

Well, I still have no Jeep, they did not get it fixed yesterday, but they did get it to run. Last words where... Found the bad wire, now they are talking to each other, and we can now fix it. We cleaned the throttle body, the fuel rail and checked all the connectors. quote-"he does not think it will be done by 5, and we dont work tomoro, he is trying to get the fuel rail clean,so it will be friday" "we are still under $500" "there is some question with the O2 sensors" my reply-"replace them" (about 120k on odometer)

Walking away yesterday, I was pleased, they seem to have it under control.

Looking forward to looking under the hood friday, there had better be lots of dielectric on the connectors! At some point I requested the ground strap and CPS be replaced, they do not think they are needed.

Thinking back, I drowned the engine last winter, had to make a round trip to Buffalo (90m there) on a lake effect morning, The snow in the drive was drifted to 4' and I "its a Jeep" floored it and went thru them, hundreds of feet of them, stopped in the lee of the shack at the road, removed the snow (a drift in itself blocking all forward view) and on I went. As she warmed up, she ran worse, leaving me sitting about

14 miles into the trip. Got up under the hood, and mechanically removed the rest of the snow/ice that was packed up and under the hood. Thankfully restarted, just sort of run like c()p Looked under while at lunch in Buffalo, stuck the O2 sensor wire back on , and forgot all about it (nice sunny day in Buffalo) This may account for the broken wire, or just massive water in the connectors that has now bit me. Then again that was a year ago, and neither rain nor snow seems to have affected operation. Fun part is , the drifts and driveway are a normal thing, done ?once a week? for years. (clean out drive after work,in prep for the next "dump")

Looking forward to Jeep'n again, as I am down to 3 beers and 1 pack of smokes!

Happy Thanksgiving!

Frank

sputtered home, parked

while, I ran the tank out, and looked

tell you that there is no comm.between

module scan. demand some money bac

Picked my beloved Jeep yesterday afternoon. most of the below verbatim, may be one or two typo's from me.

Job 1- customer states: check engine light is on runs really rough very low on gas ck and rep. (customer stated "I think I got a load of bad gas, ran it out, stuck some fuel injector cleaner in,worked great till I filled it up again, and now #1 and #4 dont seem to affect idle when pulled off) Correction: ckd for engine light on has several different codes stored inj circ open cyl 1p0201 idle cent syst eff p0505 tps cir high ect sensor circ high iat circ high input inj 4 open b 1/1 o2 sensor circ high o2 heaer malfunction bank

1 cyl 1 misfire attempt to scan for all the dtc codes scanner unable to communicate performed diag no results called star for further assistance ckd ohms and voltages on sci receiver and transmit wires cck and and compared with specs advised to hot wire sci receiver and transmit wires to bypas ecu to datalink wiring harness this showed ecu is ok and wir sci tp datalink ok ckd and started tracing for broken wires cdk wiring harness cdk supercard version to assure update ok advised to eliminate all 5 ref based sensors ckd cam cran tps map bypass cab module to assure its ok it is compared datalink pin 6&7 voltage reading with or without drb plug in share reading with start aslo noted ecu pins 27 and 29 cdk traced wiring harnesses and found ground at pin 4 of datalin traced ground from below rf headlamp repaired wire and reass and recheck system able to communicate now and reset codes rechecked with drb able to read now and communicate with 7$ for sleeves (presumed O-rings on injectors/fuel rail) 3.2$ for cleaner 96.37$ for O2 sensor (what the hay, throw one on there!!!) 780$ labor Job 2- Customer states: ck tune up (sure, Im sure it could need it, it only gets 22mpg,well,21.5 unless the Ol'lady drives it then more like 19) Correction: cdk tune up cap rotor wires look original and found rotor causing it to arc removed and replaced cap rotor and wires ck ok now 41.7$ cable pkg 11.7$ cap distr 15.99$ rotor dis 60$ labor

Job 3- Customer requests a 6cyl spark plug replacement and service platinum plugs require and additional charge

16.2$ worth of sparkplugs 63.25$ labor

Recommendations: recheck all codes and erased codes still had code for o2 sensor fai removed and replaced o2 sensor cleaned throttle body with special cleaner and reomved and cleaned injectors and fuel rail installed orings and recheck system again runs starts and no more light on

Total labor 903$ total parts 189$ tax 79$ JHMFCOAC-1171.97$

The tune up and O2 sensor were approved by me. I have put off looking under the hood. (wondering if DOC has any sample "happy pills" before I do!!!!!) If the ground points have been scraped clean and repainted/greased and the connectors are "lubed and clean" with no holes poked in wires I may be very forgiving. If the tank was dropped...................................... This jeep is slated for the junk pile some time in the year 2020. Unless they no longer sell hard axle jeeps, then I will be forced to keep on driving "her".

Thank you for your time!

sputtered home, parked

while, I ran the tank out, and looked

Wow!

So there is a main harness ground below the headlight that caused all that crap?

I for one wouldn't have guessed that in a hundred years....

Sure took the fools a long time to figure out what the computer was telling them though.....

Thanks for the follow up.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Woodsy wrote:

tell you that there is no comm.between

module scan. demand some money bac

part of the pcm

injector cleaner in,worked great till I

circ open cyl 1p0201 idle cent syst eff p0505

sensor circ high o2 heaer malfunction bank

communicate performed diag no results called

wires cck and and compared with specs

wiring harness this showed ecu is ok and

harness cdk supercard version to assure

bypass cab module to assure its ok it is

reading with start aslo noted ecu pins 27

ground from below rf headlamp repaired

rechecked with drb able to read now and

22mpg,well,21.5 unless the Ol'lady drives it

it to arc removed and replaced cap rotor

require and additional charge

and replaced o2 sensor cleaned throttle body

orings and recheck system again runs

dropped......................................

sputtered home, parked

while, I ran the tank out, and looked

chicken'd out.

Mike Romain did pass the time by typing:

Indeed. Think I will now go out to the ZJ and look at that location.

Woodsy did pass the time by typing:

IIRC, those go over the injectors to add some insulation and prevent a "rough idle after heat soak" problem.