LT1 might be LTjunk

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Oct 5, 2007 | 07:15 PM

#61

jester1614

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From: west phx

also if you have a laptop get an aldl cable and download datamaster and tunercat. the programs are free trials. and the cable is 50 or 60 bucks and is worth its weight in gold. you can log and then email them to someone to diagnose.

Oct 7, 2007 | 03:57 PM

#62

7901 WS6

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Quote:

Originally Posted by jester1614

I might just have to do that. Because I did replace the Collant temp sensor as another post mentioned to try. Only 10 dollars and it didnt correct the problem. On my return from my test drive I tried to see if any codes were stored by jumping the ground and test pin from the OBD1 connector. So I key on and I hear my FAN come one and my SES light did not even Flash

??? I think my computer might be the problem....So I spoke to a tech from a GM dealer ship and he said it might be the cat...Now to determine he said take off your 02's and do the test drive again. if the cat is clogged then at least exhaust can escape through the sensor holes and see if I get any improvement. Well did that and the car was still bogging after temps get passed 160 and my SES light came on(for the 02's) . BUT I pulled over Disconnected the MAF Sensor and the car shut off(oops) Plugged it back in started it up and finished my drive home. and The car was NOT bogging any more for the rest of the ride home......and the SES light was off.

Car is cooling down now going to put o2's back on and go for a spin again.

I am close now I think THANKS TO ALL that got me this far.

Oct 7, 2007 | 04:27 PM

#63

Scrapin'4.8

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From: Liberty SC

Well look at it this way, by the time all this is over ur gonna have all new stuff!! It's just like one big *** tune up.

Oct 7, 2007 | 05:47 PM

#64

7901 WS6

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Quote:

Originally Posted by Scrapin'4.8

Well look at it this way, by the time all this is over ur gonna have all new stuff!! It's just like one big *** tune up.

I know right!!

So o2's are back went for the drive with MAF unplugged Problem remained and SES light came on. Make a stop-Car off- Plug MAF back in-Start Car. SES light off and Drive home and Problem still remains. Get home check for codes and I get nothing no codes flashing at all not even code 12. It has to be the PCM right?? Cause it not storing codes and from closed loop to open loop its a night a day difference. The engine shut off when I pulled the MAF connector. It runs smooth at low RPM's as soon as it down shifts it runs like crap...

Oct 7, 2007 | 08:10 PM

#65

NXSLT1

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From: Clarksville,Tn

The fans coming on as soon as you turn the key might be an indication of a screwed ecm. A couple years ago mine died at the track, thought it was the fuel pump so I pulled it home. It would start and idle but I couldn't give it any gas at all or it would die. Started it up and was poking around under the hood and I just happen to bump the ecm and the fans went off so I reached over and nailed the throttle and she revved fine. Tapped on the ecm again with a screwdriver and the fans came on the car died.

What happened was I took the ecm apart a few months before that and unsoldered the chips from the boards and put sockets on the boards then put the chips in the sockets. This was so if something screwed up while tuning at the track (like loss of communication or power, I was having trouble with that at the time) I could just pop the chips out and put another set in and be on my way instead of having to send the ecm off to restore the chips. Anyway, one of my solder joints broke loose and that was the prob. Soldered it back together and was on my way, til a year or so later and it did it again and I got a new ecm. Might wanna check that out. Turn the key on and if the fans are on then tap on the ecm and see what happens. Might even fool with all the connectors going into it. Doesn't cost a dime to try it and if it works I won't charge you a thing.

Oct 12, 2007 | 02:04 AM

#66

Boodyrider

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From: Baltimore, Maryland

Quote:

Originally Posted by 7901 WS6

Fuel Filter wouldnt hurt to do again, I will do a leak down test first before anything.

Opti was replaced with a MSD, 515.00 was a better price to pay than 674.00 that GM wanted for their P.O.S.

Um. GM opti can be had for 325 brand new.

Oct 12, 2007 | 02:15 AM

#67

Boodyrider

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And may I suggest:
Unbolt the two bolts that hold ECM in place. Pull it up out of the hole. Unplug all 4 connectors, and plug them back in. Do this 3 times.

If no change:
Borrow a functional ECM, plug and see if issue resolved.

If no change:
Replace fuel filter again; you shook all the gunk loose when you dropped the tank.

If no change:
Take the opti off and replace with a new one under warranty... MSD DOES offer a warranty with their overprice POS, right? If not, contact me by PM and I'll tell you how to buy a GM opti for 325 new.