New Opti Installed now high RPM missfire

[96CERon]

96 LT4 with 90,000 miles and Delteq. Been running perfectly with Delteq for more than 2 years. Water pump was leaking again so decided to replace opti at the same time as I replaced the pump after reading horror stories here. Found opti on ebay for $149 as referenced elsewhere --depicted as "brand new made by the same supplier who makes Delco units"-- PN1104032--see Ebay post below. After removing old opti a goodly amount of oil dripped out of opti vacuum vent line??? Vent lines were also softened at the opti by oil contamination.
Replaced opti and pump along with new opti vent lines and opti drive seal. Started right up. A soon as you take RPM up to 4800 (every time) either under load or in the driveway, get severe missfire--"poping and banging." Everything ran fine right up to redline before doing this. Suggestions as to where to start looking would be appreciated.

http://cgi.ebay.com/ebaymotors/ws/e...m=150183112370&ssPageName=ADME:B:EOIBSA:MT:11

 

[gmjunkie]

96 LT4 with 90,000 miles and Delteq. Been running perfectly with Delteq for more than 2 years. Water pump was leaking again so decided to replace opti at the same time as I replaced the pump after reading horror stories here. Found opti on ebay for $149 as referenced elsewhere --depicted as "brand new made by the same supplier who makes Delco units"-- PN1104032--see Ebay post below. After removing old opti a goodly amount of oil dripped out of opti vacuum vent line??? Vent lines were also softened at the opti by oil contamination.
Replaced opti and pump along with new opti vent lines and opti drive seal. Started right up. A soon as you take RPM up to 4800 (every time) either under load or in the driveway, get severe missfire--"poping and banging." Everything ran fine right up to redline before doing this. Suggestions as to where to start looking would be appreciated.

http://cgi.ebay.com/ebaymotors/ws/e...m=150183112370&ssPageName=ADME:B:EOIBSA:MT:11

Does it do it while driveing the car??

 

[Hrtbeat1]

First I would check that all the plug wires all securely fastened, both at the plug and at the opti.



G

 

[96CERon]

Does it both while driving and in neutral

 

[96CERon]

First I would check that all the plug wires all securely fastened, both at the plug and at the opti.



G

Will check and see, but it is a delteq unit.

 

[96CERon]

Ebay opti died at 60 miles replaced with MSD unit

Ebay cheap opti failed at 60 miles--stranded me on the freeway in the dark!! Ordered MSD unit that from Summit. Got it in one day. Found that MSD now ships both a square cross section gasket and a oring for sealing the cap. If you try to use this oring it will drive you nuts.Your choice on which to use?? Warning, there is no seal installed in the delivered unit. The oring supplied is the wrong size. I went to an oring supplier and got the right size and it works perfectly (Parker # 2-162 5.737 ID x .103 thick). The oring supplied is too small in overall diameter and when stretched it will not stay in place on the small lip on the base when you go to put the cap on when the opti base is installed on the engine. A little silicone grease on the correct size oring helps hold it in position while you put the cap on. You put the opti base in with the cap off to help make sure you get it positioned on the cam dowel properly. I used the Delteq billet machined cover since I have the Delteq system. Called MSD to understand how their adjustable spark feature works. Bunch of lame answers. The installation manual suggests that you "fashion" a timing mechanism. I asked them if they understand the basic difficulty in finding top dead center and then degreeing the balancer and mounting a pointer on this engine. They seemed to be clueless. I then asked MSD if the unit shipped with the timing in the stock position. AGAIN LAME ANSWER--"turn it in all the way and then back in out 2.5 turns." Asked how many degrees per turn--answer, well about 1 degree per turn. The manual says you can adjust timing +/- 7 degrees the web site data sheet says +/- 5. Anyway if it is 5 then, if midway is 2.5 turns out that would result in a 2 degree adjustment per turn. I left it where it came.
The car is now running again and running well.

 

[Hrtbeat1]

Good to hear !!

I am not familiar with the whole Deltec setup, got a little lost with the "new" opti, thought you had gone away from the deltec :confused Anyway glad you got it going. Cheap Ebay parts ... guess I've been lucky.

I also have a new MSD unit. Yet to install, was going to try and document any performance advantage, but the dyno shop closed. Gotta get a new baseline. Thanks for the tip on the O-ring. From what I've read about the timing adjustment ... leave at factory setting.:confused I still like the billet housing, seems much more sturdy.

 

[96CERon]

Still think the Delteq is a good design

Sorry for the confusion. I replaced the stock opti as a preventive measure with a new cheap ebay opti still using the Delteq when I replaced the water pump again. The Delteq is a good design in that it removes the high voltage/arcing/corona etc. and only leaves a trigger/signal function there. They have great customer service. I recommed you replace the opti drive seal when you do you change over to the MSD. It is easy to replace. I did not like the phillips head screws on the MSD cap--go get some 8-32 stainless socket head screws instead. I think there may be more initial advance in the MSD unit since I see a higher cold idle on start up than I used to. The MSD unit appears to be well made and removes the electrical connector up to the passenger side of the intake manifold. Be careful of the vacuum vent lines and routing. Mine were ballooned and deteriorated by oil or antifreeze--probably may have been sucking closed under vacuum.

Just another point. You can replace the short water pump bolts with socket head screws. I used stainless ones. Makes it a lot easier to get that one bugger in and out that is on drivers side using a ball end allen wrench.

 

[PLRX]

I replaced the Optic with a Dynaspark. It causes knocking, lots of them. I got the ECM tuned by PCM for less and it continius. I'll buy a regular factory Optic and I guess I got rear ended with the fake Dyna stories...besides I never got any increase. Is just way more expensive...

Now, the PCM for less tune improved the performance

 

[96CERon]

Here is some info on the Delteq. This is similar to the system used on GM cars like the Northstar and a few others. http://delteq.com/ It has been used on motorcycles for years. Called lost spark.

 

[Wake]

Ebay cheap opti failed at 60 miles--stranded me on the freeway in the dark!!

Do you know by chance what failed??? I have one of those opti units from All Ignition on my garage shelf that I planned on putting in my Vette in the near future...

Guess the old saying is true, saving a few bucks cost more in the end... ;squint:

 

[c4c5specialist]

HI there,
Coil wire first!!!!!
Allthebest, c4c5

 

[96CERon]

Replaced it with the MSD unit and fired right up

Do you know by chance what failed??? I have one of those opti units from All Ignition on my garage shelf that I planned on putting in my Vette in the near future...

Guess the old saying is true, saving a few bucks cost more in the end... ;squint:

I will send it back since it has a warranty--have to get an RMA. Not sure what failed other than when I replaced it with the MSD unit it fired right up?????