Meloyelo90

Long story - short version...95 w/48k miles. Swapped opti last fall (WP died) and have had problems with the replacement since day one. Runs great until the car is warm, then just stumbles / misses etc...Also replaced opti harness, ICM, plugs, wires, etc...just to be sure, still the same issue, which again began almost immediately after the opti swap.

So last weekend I decided to remove the new opti to try and return it, and put the stock unit back in. Swapped the two, stock went back in nicely. Replaced everything but WP, accessories, and intake piece but the car will not fire. Checked and re-checked plug wires, connectors, etc...there has to be something I am missing, this opti worked fine before the swap. When I did the original swap and pulled the stock unit out, I fired the new unit up right after install and it worked fine without the accessories, WP, and intake piece connected.

Car used to fire on the first click every time. Ideas ? I am going to put the 'new' one back in to see if it fires (the one that works fine but then dies after the car gets warm), which should tell me if the original opti is bad or not. Just doesn't make any sense though. I did take the orignal opti cap off to look at it - looked great but maybe I screwed something up when I had it off ? Admittedly I am not an opti guy.

Any ideas are greatly appreciated...very frustrated.

Thanks

Randy93

Instead of throwing money at it, why not diagnose the problem.
Start by checking the harness wires are connected properly and then check the readings against the FSM.
The FSM has step by step diagnosing, do that and then run the car till it cuts off and check your readings again.
Not likely, but your PCM could have been fried at the sametime your opti went and PCM's don't usually have heat related problems like the early ECM's.

Also, check the IAC, TPS and coolant temp sensor conections, I have broken a coolant sensor and a TPS sensor replacing things on the front of a engine and also check all related wiring.
Old harness wiring is not that hard to break, not trying to bust on you, but throwing parts at a problem is not a smart way to go.

aminnich

It IS possible to put the opti on out of time on the 95s. I found that out the hard way myself a long time ago. If you are getting spark to the plugs and it won't run then I would bet on it.

Meloyelo90

Not throwing any $ at it other than 14 yr old maintenance- the opti was replaced when the WP went, other tune up parts replaced when everything was open in front of the engine last yr. Opti harness replaced due to broken fastener. 14 yr old car time for a tune up,
I was not the original owner and had no idea of the history.

I have heard of people installing the opti incorrectly, but this seated quite nicely (pin at 9 o'clock position which I think is correct, just how other opti was removed) which is why I am a bit confused. I will break out the FSM, just thought someone may have a quick idea. As I was saying in the initial post when this opti was removed it ran great.

Thanks

M. Schumacher

R&Ring the cap isn't rocket science. Only simple thing I can think of is broken rotor.

Meloyelo90

Yep - I'll put that on the list since it's coming out anyway.

Thx

pr1mu5

This would be my vote. When I put the opti back on my 94, that little mark on the spline could have easily been overridden by a small rubber mallet

When you put the opti on, did it slide on really nice and easy, or did you force it a little? Not sure if the 95's have the little notch in the spline like my 1994, but that could be the issue.

Randy93

Like I said earlier, check the IAC, TPS and coolant sensor. Any of the 3 will cause problems when the car try's to go into closed loop.

Sorry, thought you were posting what you did after the problem was found.

aboatguy

95 is a little different and easier to get on out of time