Make sure that you have the wires correctly connected to the Optispark.Thanks Sinister! I'm picking it up tomorrow, I could tell the guy was clueless after speaking to him. He couldn't get a reading on the obd1 so now he THINKS I have a wiring problem!
You need a new vacuum hose & restricter assembly that runs from the opti-spark to the intake plenum. See pictureI have a 94 SS and so far I've changed the plugs, wires, fuel pump, fuel filter, MAF, optispark, and injectors but the car still backfires and sputters under load! Any advice you could give me would be much appreciated!
Unfortunately finding folks who can and have the tools to scan 94/95's right is very rare.Thanks Sinister! I'm picking it up tomorrow, I could tell the guy was clueless after speaking to him. He couldn't get a reading on the obd1 so now he THINKS I have a wiring problem!
Thanks a lot, I'll try it!You need a new vacuum hose & restricter assembly that runs from the opti-spark to the intake plenum. See picture
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That's very true, unfortunately!Unfortunately finding folks who can and have the tools to scan 94/95's right is very rare.
-Brian
Thank you!!A common request by reply-ers ends up being to ask what exactly prompted the flurry of throwing parts at it in the first place. The same "backfires and sputters under load", or something else?
To madamorr's point I claim a perfect record of getting EXACTLY 2 wires wrong every time I replace them.
I take "I've changed" as meaning you did all the work up til now yourself. If so, the perfect way to spend your time and $$$ the best is to invest in the Fact. Serv. Manuel for its great diagnostic trees on running issues.
I can't seem to find this anywhere for a 94, only the 95-97. Will this fit the 94 by chance?You need a new vacuum hose & restricter assembly that runs from the opti-spark to the intake plenum. See picture
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Ok, I'll look into this. Thanks a lot!I've read (on this forum) that ALL Impala SSes got the vented harness, regardless of year. Confirm on your own at will.
The symptoms that you initially had were identical to what I had on my 94 9C1, and just as you stated, I "threw" all the "parts that just had to fix it" except for that vacuum assembly. At the time I did not know that the LT1 could not run correctly without the restricter valves & hose assembly. What I over-looked was that the larger valve had 'blown out' the restricter portion which then allowed un-metered vacuum into the intake. Check Hamilton Chevrolet on Ebay:Thanks a lot, I'll try it!
Fixed it.… ALL Impala SSes got the vented harness, regardless of year.
Thank you, I just ordered it! I hope this is EdgThe symptoms that you initially had were identical to what I had on my 94 9C1, and just as you stated, I "threw" all the "parts that just had to fix it" except for that vacuum assembly. At the time I did not know that the LT1 could not run correctly without the restricter valves & hose assembly. What I over-looked was that the larger valve had 'blown out' the restricter portion which then allowed un-metered vacuum into the intake. Check Hamilton Chevrolet on Ebay:
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Impala SS~Opti-Spark Vent Vacuum Harness~LT1 Caprice~9C1~Buick~OEM GM~12555323~ | eBay
Genuine GM Part that will replace the one on your vehicle that has dryed out and left your Opti-Spark not working correctly. 1994 - 1996 Chevrolet Caprice 9C1. 1994 - 1996 Chevrolet Caprice SS. 1994 - 1996 Chevrolet Caprice.www.ebay.com
Thanks, I just ordered it! Hopefully this is a lifesaver, thanks again!The symptoms that you initially had were identical to what I had on my 94 9C1, and just as you stated, I "threw" all the "parts that just had to fix it" except for that vacuum assembly. At the time I did not know that the LT1 could not run correctly without the restricter valves & hose assembly. What I over-looked was that the larger valve had 'blown out' the restricter portion which then allowed un-metered vacuum into the intake. Check Hamilton Chevrolet on Ebay:
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Impala SS~Opti-Spark Vent Vacuum Harness~LT1 Caprice~9C1~Buick~OEM GM~12555323~ | eBay
Genuine GM Part that will replace the one on your vehicle that has dryed out and left your Opti-Spark not working correctly. 1994 - 1996 Chevrolet Caprice 9C1. 1994 - 1996 Chevrolet Caprice SS. 1994 - 1996 Chevrolet Caprice.www.ebay.com