New Wires/Opti...wont rev past 3k.

[nascarnate326]

any of this look bad?

[my95z28]

You need to go rent a fuel pressure gauge from the parts store Nate. Could be the pump itself is bad

[bri2203]

It is not the fuel filter.

why did you replace the opti? Was it a NEW opti or new to you?

[nascarnate326]

brand new opti, car had a hesitation off idle and when I would shift from WOT one gear to the next it would stumble as soon as I got into the new gear, take a few seconds and then come back on full power.

[JoeliusZ28]

just because of the course of events id say it has to be the opti, but may also be a combination of a weak coil amplifying the issues.

[98blackbeauty]

You can put the opti on wrong on a 95 -97. there are 3 funny shaped openings and then there is the round drive hole. we actually installed the opti in the wrong opening and it clicked right in on B's car. He was 180* out so was more obvious. You might be 20-35* out and it could be problem. Also old opti might of been fine and you had other problems and new one with wires changed symptoms.
Up until this happened to us we thought the round drive pin would NOT go into other holes. But, it will, and drive can be anywhere and mount holes will line up.

[nascarnate326]

Just called on a new GM opti...$700 +.

Holy Crap..

I think I am going to try a few other things first.

[Darren]

Just called on a new GM opti...$700 +.

Holy Crap..

I think I am going to try a few other things first.

Is it possible you got a bad opti from the place you ordered it from? I would not rule that out.

[meissen]

I honestly will never install an optispark again without being able to hold onto the rotor (meaning the front case is off) and ensure the hole lines up perfectly.

[nascarnate326]

I honestly will never install an optispark again without being able to hold onto the rotor (meaning the front case is off) and ensure the hole lines up perfectly.

Is yours the 94 style? or the 95-97 style?




Yes, very possible the opti could be bad.

[FASHOOTER]

Just called on a new GM opti...$700 +.

Holy Crap..

I think I am going to try a few other things first.

Jegs and Summit sell GM optis way cheaper than dealer

[nascarnate326]

this is exactly what my car does:
http://youtu.be/FUjHeIaSI0M


I did drop by MAF...kind of thinking that could be an issue. Seems more probable than the opti.

Gonna start with testing the fuel pressure, install a new fuel filter, and then unplug the MAF and see if it does anything.

[meissen]

Is yours the 94 style? or the 95-97 style?

95 vented opti. The problem with them, IMHO, is that when you take them apart one side of the rotor is heavier than the other. So you can position the hole, let go of the center rod while you go to slide it on, and the rotor can spin around on you while you're sliding it into position and you wouldn't know it. That's what happened to me. Mine slid on very easily, I didn't have to use any force, yet it went into the wrong hole.

If you dropped the MAF, then yeah I'd start there. But Optis are known to not like 6k RPMs either. Wish your car was a 95 so I could hook it up to my diagnostic scanner and help with datalogging. The tool you showed earlier -- is it yours or rented? See if you can hook it up to someone else's and then compare readings.

BTW - the MAF reading you posted above is spot on for idle.

Note - to convert grams per second to pounds per minute:

grams/second = pounds/minute x 7.56

Example: 30.0 pounds/minute x 7.56 = 226.8 grams/second

At idle, the air mass flow will range from as low as 6gps to as high as 10gps. If you reading is suspiciously low, you may have a vacuum leak. If it is suspiciously high, and the idle speed is correct, it's most likely a "faulty" or "miscalibrated" MAF. This problem is typical of "home ported" units.

At WOT, the peak air flow in a stock, normally aspirated engine, with a 5,800rpm rev limit will be about 240gps.

Your picture above puts the MAF reading at 8.6148 gm/s. My dad's at idle is around 7gm/s.

[nascarnate326]

Thanks Brian.


The scanner I posted was purchased, but everyone around has LS cars.


MAF seems dead on...damn. That would certainly be the easiest fix.

We are getting a MAF from Schroyer to test with. If it makes no change I will just take it back.


Fuel pressure is supposed to be at 41 lbs?

My dad took the car to the local garage and they say it has a "lean fuel condition"...whatever that means. That could only be a 100 different things.



EDIT: MAF shows at 1.x.....that would be crazy low...right?

[nascarnate326]

Baring any unforeseen issues....my car runs perfect.

Changed the MAF with one out of a 95 corvette and it revs, starts, stops, pulls, sounds, idles just the way it should. My car is soooo smooth now. No delay in the power.

Kind of wondering of the opti was ever my problem now.


Anyways I learned an opti is NOT that hard to install, and that my Chandler Motor Sports opti works fine right now with 22 miles on it. Lets see how long it lasts. Thanks to everyone that helped.

Now on to the next project..