98 jimmy 4.3/auto SLS 4x4 4 door in california(smog crap)
$5500
march 06-mechanic diagnosed bad fuel pump but ran GM FI cleaner and we drove 100 miles back home no problem. replaced anyway.
$950
by summer it was doing the same thing. warmed up-come to light or sign, dies and wont restart until under 100 degrees on temp gauge.
took it back to FP mechanic, they said its fine,-cant/wont fix it, try cam/crank sensors-(never going back) took it to pep boys to do.
$500+
same driveability problems except now wife gets driven by me almost everywhere longer than 2 miles as shes scared to drive it.
new alt
$$$$

drove to sac to get empty car trailer in hot weather. driving warmed up, come to stop, (heat soak) =dead. wont start until either cooled off or about 1 gallon of water slowly poured on intake. finally killed battery and nervous as heck to take it the 100 miles home. had to recruit friend and jumper cables and drag teh POS up onto trailer i just bought to drag teh 98 home.

took it to chevy dealer-they cant figure it out but i told them about poppit valve and its GMC so they send me to GMC dealer.
5-7 times in shop over 4 weeks at 2-3 days/time...
$150 diagnostic=ZIP/ZERO/ZILCH
they left it running in 100' weather and then tried to make it die=nope. they say new fuel pump for $1500=broke so no.

new FP regulator.
$50

now wife has to have surgery in march 08 and so the only car we have she can take teh trip to UCSF is her POS car.
does "great" getting a whopping 14mpg on teh 175+ freeway miles trip to SF.
drive it around town a few days while shes in hospital.
night before need to take her home i shut the car off and FP wont turn off.
finalyl get it to stop by pulling relay.
back at hospital it wont start and i crank so long i kill battery.
AAA comes to jump me-nothing. crank and crank and no fire.
in the morning i ride teh bus all around SF to buy new battery and FP relay.
$130

get it to fire and run
sooo scared to shut it off-left it running the whole rest of the day on teh way home -food/rest stops.. etc.
it died once. BARELY chugged to a start after a lot of hard cranking and swearing.

175 miles home, slow down to turn into driveway=DEAD. push it teh rest of the way off road.

buy wife 91 CRX for a MPG car to drive and 48 chevy truck to go to work in.
$4000

took it to the dealer-different one with supposedly rave reviews.
they say ign module is bad-maybe. they claim bad batt cable is causing problem. they want to replace ign and cable and re-flash for $500. i say NOT ECM if water cooling intake area makes it run.
there it sits.(cant be cable otherwise it wouldnt even crank after dying)

anyone want a $11,130 POS car? make you a hecka deal. less than 120k miles. power everything.
530-892-2242

i swear its the poppet valve and/or one of the plastic lines inside manifold leaking as well as intake gasket.
ideas?

DAMN COMPUTERS!
BTW-no codes EVER and computer light works fine. it tended to eat water so i replaced rad cap-seemed to help. followed up on threads and found leaking intake issues. might try that next-want the POS GONE!
mark

 

I understand your frustration, however not every problem is cut and dry. Not following the recommendations of the experts doesn't help the situation usually. you have to understand that the dealers have to follow procedures.

Have you had the ICM tested?
If it wont start while over 100 degrees temp it could be the Ignition control module, or it could be your fuel is vapor locking and the trouble just might lay in the fuel deleivery/ return system. typicaly no codes indicates a fuel problem. GM doesn't monitor fuel, it assumes you have enough pressure.

Regardless, where do you live? If its in the midwest, I'll but it for $50.

 

i am very mechanical and feel quite strongly that it is a fuel problem. somthing like either vapor loc, the poppit failing under high temp, or maybe the manifold lines are cracked and split open under pressure at a threshold temp.
it acts exactly like vapor lock.

the fact that dumping a gallon of water on top of engine under this condition is the ONLY thing that will allow it to start confrims it in my mind.
i have never dumped cooling water in ign module or ECU... so kinda rules that out in my mind-i have been wrong before-hence the cry for help.
i am taking any suggestion.
however-i have been offered 2500 and obviously wont take less than that.
thank in advance.

i live in chico,ca and we regret strongly selling out 85 2d jimmy. if it was a 4dr never would have sold.

 

i was having the same problem with my oldsmobile and thought it was a fuel problem too, but if you already replaced the fuel pump i would go with the ignition control module. thats wat was wrong with mine, it would drive fine then once i pulled up to a light or backed out of throttle it would die and not start. after replacing the icm never had the problem again.

 

The ICM is bolted to a heat sink that is bolted to teh intake/valve cover. Pouring water on the intake will cool the ICM as well. Doesn't take much to take it off and take it to a autoparts store and have them test it. Make sure hey test it like 10 times in a row, you want that sucker hot. the early sign of ICM failure is they quit workering when hot, once cool they work again.

Only way your going to get vapor lock is if you ahve a plug in the return line. Verify your fuel is returning to the gas tank. If its not, then the excess fuel will sit at teh FPR cooking until it gets used.

 

i did not realize where teh ICM was-i thought it was the whole brain on the fender... hence my doubt it was ICM...
if its that thing on the valve cover-then YEAH-i put water all over that and it made it work...

 

update-
replaced lower manifold gaskets, my year has external steel fuel line so no worries tehre.
fuel line was missing o-ring-replaced.
replaced all gaskets in upper manifold.
did water pump...
hooked FP gauge to line, turn key=51# for 2 sec till FP turns off normally. then FP dies to 10# in a milisecond tehn to zero in about 1 full second.

drove it last night. ran not perfect. with fpg hooked up it idles at 51 and then when you step on it under load it goes to 56/7. as soon as load goes away(lift foot or bring RPM up) it goes to 51.
its a kragen 40$ gauge so accuracy might not be perfect but...

pulled into garage and FP futtered/dropped to 42-6 and it almost died. then it recoverd after throttle stomp and was not fun...

FP dead or other issue?

does teh ICM when changed need to be flashed?

 

Not to the flash of hte ICM.
Teh brian on the fender is your engine puter.

Sounds like you have a fuel pressure problem. Search the forum, tons of info on how to diagnose it and what the proper fix is. Pressure sound maintain for a long time, unless you have a vacuum leak. Your fuel system is a closed loop system, it maintains pressure, hence the sucking noise when you take the gas cap off. You do have a gas cap correct?[8D]

 

So-I do NOT need the computer programmed if i change the ICM(ignition control module?

I have a good gas cap.

It is probable I have a bad vaccum hose somwhere as the rats or abrasion killed the 4x4 with PO and it was a LONG section missing off half the vac line running to pot under battery.

After getting a full cart at rockauto.com i found an article they posted(PDF) from Carter fuel pumps shwoing the HORRIBLE GM fault of melted connectors.
I am willing to bet my fuel pump is fine and there are bad wiring or vac lines all over that car.
I downloaded a PDF from carter showing how to load test thh FP cause just doing continuity wont show fault.

So after my test this weekend and I get my 2 vacancies in teh apartments filled iw ill be trying to make space in the garage and pulling the fuel tank to get at wiring and FP to do load test and inspection. I suspect D$%%&^ shop who swapped FP under 5,000 miles ago did NOT replace wiring connecter as recommended by all.

Thanks-keep the good info coming.

No flash for ICM right?

 

NO, you do not need to do anything with the PCM when you replace the ICM.

As far as the wiring, I have seen wiring splice jobs cause excessive resistance and a no start condition. It is possible that the shop that did the replacement just didn't seal up the wiring properly. I find that the 3M shrink wrap butt connectors work great in applications such as these. They have a heat activated glue inside that completely seals the connection as well as strain relieves the splice.

Hope this helps!