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NAISSO
NAISSO Admin
723 Posts |
 Posted - 07/15/2010 : 21:38:12
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Hi, trying to assist our local chevy dealership.
They have both a 95 and 96 SS in the shop with the same issue and asked us for some feedback.. The cars will start and run for about 30 mins to full operating temp and then quit with no spark. Let them cool for about 15 mins and they will start and run for about the same time and then quit. The 96 had a brief spell where it took a trip for about 900 miles and then came back locally and started doing the same thing. They have replaced Optispark units, Opti wiring harnesses, coils, ignition modules, etc. No luck.
Have any of you had any similar symptoms with successful fixes  What did you find?? |
Troy
Palm Coast, FL |
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96ssBBB
level 5
USA
5779 Posts |
Posted - 07/16/2010 : 00:21:15
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Hey Troy
It is very odd that both cars a exhibiting the same malfunction at the same time. But I had the exact same problem when I bought my Roadmaster. I know you said the Opti had been replaced, I also replaced mine twice with aftermarket units (being cheap trying to save $ ). But I still had those symptoms until I replaced the Opti with a GM unit from Summit. Part number 1104032
http://www.summitracing.com/parts/ACF-1104032/
Word on the street was that there was a bad batch of the aftermarket Opti’s going around. About the same time I was having my dilemma with the Opti so were quite a few others. The GM Performance Opti from Summit solved my problems immediately
The only other suggestion I would have would be to ask them to check the Opti vent harness. While it would be odd, again for both cars to have the same problem at the same time these cars are getting older and these parts do need to be changed.
Harness GM part number 12555323
http://www.rmsautoparts.com/proddetail.php?prod=12555323
Allan
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RIP -SStropper
RIP - Wayne Beaman http://www.vimeo.com/6728716
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Edited by - 96ssBBB on 07/16/2010 02:49:03 |
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NAISSO
NAISSO Admin
723 Posts |
Posted - 07/16/2010 : 07:23:37
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Thanks Allan, yes they were replaced with oem opti's. Not sure over what period of time.. i'll check.
the vent harness would only be a moisture build up thing correct? T |
Troy
Palm Coast, FL |
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Bloodvane
level 5
Somalia Southern Region
3479 Posts |
Posted - 07/16/2010 : 10:41:11
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I laud them for their candor in reaching out to the community. All too often dealerships act somewhat aloof/arrogant when they can't pin something down. Even a Chevy dealership could learn quite a bit from this thread:
http://www.impalasuperstore.com/naisso/Forum2009/topic.asp?TOPIC_ID=47010
and yes, I agree w/ Allan that it does appear to be opti related even after having replaced them w/ new. If both cars had replacements and are now exhibiting similar issues, that's more of an affirmation that the replacement units may indeed have been faulty. make sure they read the part about the Mitsubishi optical sensor and loc-tite on the rotor hold down screws. Those 2 items respectively account for the vast majority of post-opti replacement failures. Original equipment opti failures are invariably cap/rotor and water/oil infiltration related failures.
Other possibilities:
- ICM - Yes, thye replaced them, but did they clear the heat sink of all crud/grease? It's actually better to remount them off the block using a couple of washers behind as spacers.
- Crank position sensor for the 96.
- Check the auxiliary positive terminals. If OEM, replace.
- Did they service the seals while the opti(s) were off? An oil leak behind the opti will ruin it in fairly short order. See:http://www.impalasuperstore.com/naisso/Forum2009/topic.asp?TOPIC_ID=30984
- Check the air pump check valves. When they fail, it isn't until operating temp is achieved that they'll manifest their problems.
- EGR. Not very likely, but test them for ***s and giggles.
- Partially or almost completely clogged cat. Passenger side in particular.
- I'm reaching now. Time to stop.
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96ssBBB
level 5
USA
5779 Posts |
Posted - 07/16/2010 : 14:18:59
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quote:
Originally posted by NAISSO
the vent harness would only be a moisture build up thing correct? T
That’s kind of how I looked at it as well Troy. But somewhere some dork found an article that described how Ozone gas was created inside the opti and would cause premature corroding of the terminals.
I’m not sure I put a whole lot of faith in that theory, but it is a "vent harness" so it would release gas if any were to build up. But IMO the harness should be changed on higher mileage cars just because of the risk of clogged check valve and deteriorating materials.
Bloodvane brings up a good point about the seals; leaking seals would be a knockout punch to an opti GM or aftermarket. So when they pull the Opti tell them to open it up, possibly going to be crapped up with oil.
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NAISSO
NAISSO Admin
723 Posts |
Posted - 07/16/2010 : 19:25:23
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thank you all great feedback.. I will pass along and will post any results.
thanks, Troy |
Troy
Palm Coast, FL |
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NAISSO
NAISSO Admin
723 Posts |
Posted - 07/17/2010 : 10:04:45
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Have any of you had the described operating temp problems where the car quits running after 30 mins? I can see longer term opti problems with moisture but what do you think would quit inside the opti once it reaches operating temp and then runs again when it cools? maybe a bad oem connection within the unit?? just thinking out loud.
Also, i like the secondary battery post meltdown mention. Allan, I haven't been in that fuse box in a while.. are there ignition related or pcm fuses in there?
oh, i forgot to mention in my first post that these cars are not throwing any trouble codes.
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Troy
Palm Coast, FL |
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96ssBBB
level 5
USA
5779 Posts |
Posted - 07/17/2010 : 10:52:40
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quote:
Originally posted by NAISSO
what do you think would quit inside the opti once it reaches operating temp and then runs again when it cools?
That would be this little gem, aka the optical reader.
When disassembling the opti have them look for the Mitsubishi logo, no Mitsu logo, it’ll be an aftermarket unit.
quote:
Originally posted by NAISSO
Allan, I haven't been in that fuse box in a while... are there ignition related or pcm fuses in there?
Errr, I want to say yes, but off the top of my head I can’t remember which one it is. I'll get back to ya on that one.
edit:
There is a fuse, it's a 10 amp in the middle of the underhood fuse block.
quote:
Originally posted by NAISSO
oh, i forgot to mention in my first post that these cars are not throwing any trouble codes.
Mine never threw any code either.
Allan |
Edited by - 96ssBBB on 07/17/2010 22:03:15 |
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Bloodvane
level 5
Somalia Southern Region
3479 Posts |
Posted - 07/17/2010 : 12:52:47
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"Have any of you had the described operating temp problems where the car quits running after 30 mins? I can see longer term opti problems with moisture but what do you think would quit inside the opti once it reaches operating temp and then runs again when it cools?"
Just to shed personal insight into the former question, I'll rehash my experience. Cheaped out on an EBay opti (complete unit) figuring to save some dollars and give it a try. After as many tear downs to the opti as I've done by now, it's a piece of cake for me at this point although for the 1st timer, it can be a nightmare. If I had to go back in, I wasn't too concerned. Opti ran perfectly for a couple weeks. The optical sensor failure occured suddenly and I can pinpoint it to one wot launch onto an I-95 ramp near Pompano. The car started hesitating badly and would cut into and out of converter lockup inconsistently. Got it back home and experienced bouts from then on virtually everyday when the car wouldn't start at all or would take several attempts. Cut to the chase, the aftermarket Chinese optical sensor simply can't tolerate high RPM's. Once you push it above a certain point, the OS fails. The failure can be total (car won't turn over at all) or intermittent (some days it's fine, still others it won't turn over). What the dynamic inside the unit is that allows for such intermittent results, I can't say. Still had my OEM opti and switched that OS into the EBay housing. This was when I studied all the parts and realized the Misubishi/aftermarket difference. Reinstalled and problem resolved ever since.
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NAISSO
NAISSO Admin
723 Posts |
Posted - 07/17/2010 : 16:28:59
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| perfect.. thanks. |
Troy
Palm Coast, FL |
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impalasspeed96
level 5
3358 Posts |
Posted - 07/25/2010 : 05:48:21
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| I had the same issue. Don't ask me how or why, but it was the coil.... |
-96 SS DCM
-12.74@103, 1.74 60' out of fuel again.... When will I learn.
-06 AWD TBSS
-12.58@106, 1.76 60'
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The Fooser Guy
level 2
442 Posts |
Posted - 08/02/2010 : 12:50:38
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I'd be looking for a heat related issue ('runs for 30 minutes then shuts off') where something was heating/expanding and losing contact. +1 for un-bolting and checking the coil, ICM and ECM gound at the front of the driver's side head. Not saying it's not an opti related issue - it could even be a bad/cracked opti-connector (the small wire-clip-connector at about 10 o'clock on the opti, get a loose pin in there and things don't read right either.
$0.01 |
The Fooser Guy
"Diagonally parked in a parallel universe."
For the details and a few un-expressed opinions: http://i368.photobucket.com/albums/oo124/TheFooserGuy/TheFooserGuy.jpg
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SOB 9C1
level 4
1391 Posts |
Posted - 08/30/2010 : 20:01:26
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dont know if y'all got this fixed up yet but...
i had the exact same thing with my L99 and it was so simple it was difficult! i felt like a re-re. the 94 would run great for bout 30 min then die. my buddy looked it over for a day and found it was the ICM. the heat made it break down. he ran it for awhile in his shop to show me, it got warm and died, shot some air at it to cool the ICM and it fired right up and ran great. we threw another ICM on he had layin around and never had the problem again. |
UPPER MIDDLE CLASS WHITE TRASH!!!
"HUCKLEBERRY" 1987 3/4 ton Custom Deluxe 4X4
"BLACK WIDOW" '96 9C1 UNDER CONSTRUCTION
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The Fooser Guy
level 2
442 Posts |
Posted - 08/31/2010 : 16:53:50
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And this one just happed to me on a road trip (but it's probably a bit of a stretch unless you are running a similar intake):
History: I normally run a 'Home Depot Ram Air' intake system (110 sq. in intake that replaces the entire center section of my front air dam), with an (insulated) 6" diameter vertical 'stack' coming up between the radiator and water pump, that feeds thru a K&N and into the MAF/TB/intake. The theory is that when the PCM sees 'more air' it squeezes in 'more fuel' and makes 'more power'. But seeing as I was going to make a 1800 mile road trip, I opted to remove the lower 'intake' portion and let it just draw air up the tube ('less air' = 'less gas' = 'more mileage'). I also run a digital ($10) air-inlet temp probe that shares the space with the OEM unit. And I have hand-fab'd alumimum fuel-rail covers.
Story: So after 12+ hours of near-constant highway 'cruising', I'm motoring down the highway in the heat of the day and my inlet air temp is climbing to nearly 140F (this is the 'down side' of getting your intake air from 5" above the hot road surface - hence the new intake design I'm playing with)... and the car decides it 'does not want to take any fuel' (acting like a vapor-locked carb'd car).
Cutting to the chase; I believe that the combination of the high heat of the day, the high inlet air temp (heating the intake manifold and fuel rails) and the aluminum fuel rail covers keeping all that heat near the fuel rails - I was nearly 'boiling' the fuel in the fuel rails and failing to get good fuel delivery to the injectors. Since I was already at the side of the road, I took off the vertical stack (etc.), filter shroud and the fuel rail covers - and the car went back to running just fine (inlet temp dropped to 110F or so (still 'high' due to underhood temps - but it ran fine).
Dunno if this applies to your issues, but it might?
(Sidebar: I've never had this issue come up with the 'lower unit' attached, presumabley the 'cooler air' (that has not been thru the radiators) coming up the 'stack' keeps this heat soaking from happening)
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The Fooser Guy
"Diagonally parked in a parallel universe."
For the details and a few un-expressed opinions: http://i368.photobucket.com/albums/oo124/TheFooserGuy/TheFooserGuy.jpg
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Edited by - The Fooser Guy on 08/31/2010 16:59:52 |
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Driveability issue 95 and 96 both same symptom
