OPTI - MSD or Dyna?
Instructor
Joined: Dec 2005
Posts: 101
Likes: 0
Burning Brakes
Joined: Jul 2006
Posts: 1,230
Likes: 0
From: Sulphur LA
I too replaced my opti w/MSD components and it didn't fix my high rpm miss. 
I have been going back over EVERYTHING to see if I missed something (bad plug/arcing wires) and haven't fixed the problem yet. It is either ecm/harness related or mechanical. My lt4 has 80k but it may be time to look into a 383........
I have been going back over EVERYTHING to see if I missed something (bad plug/arcing wires) and haven't fixed the problem yet. It is either ecm/harness related or mechanical. My lt4 has 80k but it may be time to look into a 383........
Thread Starter
Le Mans Master
Joined: Feb 2000
Posts: 9,600
Likes: 88
From: Springfield PA
Philly 'Burbs Events Coordinator
When I had done the opti last time I had put anti seize on the harmonic hub so it popped off with a few hits. First time it was tough, I used a piece of wood between it and the old opti and had to rotate the engine at each little bit pryed till it would come off.
I too replaced my opti w/MSD components and it didn't fix my high rpm miss. I have been going back over EVERYTHING to see if I missed something (bad plug/arcing wires) and haven't fixed the problem yet. It is either ecm/harness related or mechanical. My lt4 has 80k but it may be time to look into a 383........
I have been going back over EVERYTHING to see if I missed something (bad plug/arcing wires) and haven't fixed the problem yet. It is either ecm/harness related or mechanical. My lt4 has 80k but it may be time to look into a 383........
Instructor
Joined: Dec 2005
Posts: 101
Likes: 0
I don't work fast so it took me about 4 hours.
When I had done the opti last time I had put anti seize on the harmonic hub so it popped off with a few hits. First time it was tough, I used a piece of wood between it and the old opti and had to rotate the engine at each little bit pryed till it would come off.
When I had done the opti last time I had put anti seize on the harmonic hub so it popped off with a few hits. First time it was tough, I used a piece of wood between it and the old opti and had to rotate the engine at each little bit pryed till it would come off.
I usually take my time & go over everything twice & three times.
Just trying to get an idea of what I'm looking at (big picture) before I go in. I've replace the water pump, radiator, heater core, & starter in this car so far...so I have a general idea.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Does it happen all the time, or only when warm? Next time, pull the cover off the ECU, then hit it with some cool spray, see if things start to work better. or, strap a ziplock of ice atop of the computer, and see what it does as things get warm.
Thread Starter
Le Mans Master
Joined: Feb 2000
Posts: 9,600
Likes: 88
From: Springfield PA
Philly 'Burbs Events Coordinator
I like fuel pump, not so much a fan of the computer. They are weird, but usually just quit... If it's the original, tho... hm... capacitors and such just start to go outside of their expected range and all bets are off.
Does it happen all the time, or only when warm? Next time, pull the cover off the ECU, then hit it with some cool spray, see if things start to work better. or, strap a ziplock of ice atop of the computer, and see what it does as things get warm.
Does it happen all the time, or only when warm? Next time, pull the cover off the ECU, then hit it with some cool spray, see if things start to work better. or, strap a ziplock of ice atop of the computer, and see what it does as things get warm.
I just took a cruise with it missing and a fuel pressure guage on it.
It's not the fuel pump guess I'm doing a leak down test next, unless someone has another suggestion.
Thread Starter
Le Mans Master
Joined: Feb 2000
Posts: 9,600
Likes: 88
From: Springfield PA
Philly 'Burbs Events Coordinator
I was just reading the FSM going through some of the trouble shooting procedures and one of the things it said to check was the EVAP solenoid check valve.
Using the chart it says I have a bad solenoid.
Could that possibly cause the problem?
Using the chart it says I have a bad solenoid.
Could that possibly cause the problem?
Thread Starter
Le Mans Master
Joined: Feb 2000
Posts: 9,600
Likes: 88
From: Springfield PA
Philly 'Burbs Events Coordinator
I report back in a few hours if this solved the problem
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Thread Starter
Le Mans Master
Joined: Feb 2000
Posts: 9,600
Likes: 88
From: Springfield PA
Philly 'Burbs Events Coordinator
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
I would do the leak down and go from there.
It may also be worth removing the valve covers and checking for play in the valve train. You may also have a weak lifter... never know for sure. Something like that would make a tick, tho.
As an aside, a friend of mine here has an early 90s MR2 turbo. It was running ok, but down on power. No noises, just weaker than normal(no comments, ok?). He did a compression test and one cylinder was DEAD. He found the exhaust valve was cracked, causing a pressure loss in that cylinder, killing performance.
It may also be worth removing the valve covers and checking for play in the valve train. You may also have a weak lifter... never know for sure. Something like that would make a tick, tho.
As an aside, a friend of mine here has an early 90s MR2 turbo. It was running ok, but down on power. No noises, just weaker than normal(no comments, ok?). He did a compression test and one cylinder was DEAD. He found the exhaust valve was cracked, causing a pressure loss in that cylinder, killing performance.
