Ramrod92

I've got the dynotech on the front of my 396. Haven't got it in the car yet. It does seem like a high quality unit I'll be posting more info when I get it fired up. :thumbs: :steering:



[Modified by Ramrod92, 4:13 PM 4/22/2003]

The Example

I have been having the same problems with an erratic idle as the engine warms up. Also have had intermittent "stuttering/rev limiter" type issues under load, but I havent had any of that in the last few tanks of gas.

Another issue - my gas mileage is **** poor. Like 13.3mpg whether city or highway. Yeah, my driving habits are partly to blame, but even when I baby it, I get the same mileage. Any thoughts?

John Row

Sounds like your OPTI fixed itself.

Mine did as you described, fixed itself, then decided to strand me in a parking lot. It started after about 20 minutes of me wiggling wires and swearing (right before I posted the FOR SALE sign).

It gave me the codes for low and high ignition sensor resolution when I got home.

After a new opti the love affair is back.

C4

Ok, update and additional request for insight. Changed out the opti, did the upgrade, put in a new waterpump, cause the one I installed last year was leaking from the weep hole and the car still runs pretty poorly. Thinking it might be in the ignition module. Symptoms: Hard starting. Then when it does start, its like it's running on 6 or 7 cylinders. It is also backfiring a bit. Any thoughts on what I should look at next. Would like to get on the road before the troops come back from Iraq...-C4- :flag

SPD DMN

Check to make sure you did not cross any wires when putting the opti on. Easy to do as I do it 9 out of ten times I do wires or swap opti's. Symptoms sound just like it.

John Row

If this is new behavior then

:iagree:

Else, it's not unheard of to get a bad new optispark. Eliminate everything else first.

SPD DMN

Just to elaborate on why I found I messed this up the majority of the times. The two sides are setup differently. I made the assumption for a long time that the order was the same on both sides of the optispark. Where on side was 1, 7, 3, 5 the other side would logically be 2, 8, 4, 6, when in reality the drivers side is 1, 7, 3, 5 and the passenger's is 2, 8, 6, 4 (from the bottom up).

Chris

lloyd430

I have a 93 and when she heats up and more so on a hot day the car has a hicup total loss of power and will even stall out. Mechanic has the car now and says its the OPTI . I will post when I get it back to see if its gone or should I say it better be gone. From what I see it will end up between $900 and $1300 Baaaaaaaaa!!!!!!!

cormorant71

That is how my opti began its death march. Also, the fuel pump was going bad at the same time.

Then next symptom I experienced was a skipping using light throttle while cruising at 40-70.

kcbc

what condition it occur ???
is it during overnight cold start ? ...or after total warmup on a quick shut down and restart ?

kcbc

I have a 96 impala SS ...same set up on C4 corvette with 160 K miles
never had a problem...
I also work on a 1997 transam same set up ..just run bad all over no matter what ....codes only said random misfire....P0300 ..typical GM running bad code on engine driveability




let me tell u all what it took to figure out and fix it....
in order to replace this distributor ....everything in front of the
harmonic balancer must come out....I believe in diagnose scientifically
rather than parts swapping .....cuz this parts is over $500 from GM and the labor is not cheap ......
It took me 3 days until I pull my scope and watch the input signals on crank and firing commands on cylinders ....it skipped cylinder identification id on some cylinders to fire ....
after all replacement and fixes cars runs good but ..just for the
diagnostian primciple ..I cut open the defective unit...nothing looks bad physically includes the 360 degree slots on the opti sensor......only thing I know it cant be test is the opti sensor which is completely sealed .....kinda looks like a driver inside the computer....
all in all ...if I didn't use my scope ......nothing can be proof nor identify to nail the opti spark

don hall

OP started this thread 12 years ago............

lloyd430

This only happened on a hot day after about an hour or so riding. When she is cold on a 20-30- min ride it was perfectly fine. I will be getting the car back at some point this week and send an update. At this point he is changing OPTI AND WATER PUMP.He said the OPTI is my problem it was full of rust as well.

kcbc

that's very good ....u shouldn't need to tell what ur mechanic need to do or check on him .....but if that don't fix the problem .....he better give u the parts and labor for free ........cuz that's the difference between parts changer and a real tech