my car just quit on the freeway--help!!!

[poorboys831]

hi people need some ideas here before i talk to the dealer in the morning.Just filled up with amaco premium,driving home from Atlanta <after a beach boys concert.Cruisin' down the interstate at 75mph with the cruise on.Passing a semi and all of a sudden I loose power,car bogs down, then back up and starts to back-fire like it's a machine gun. I finally get behind the truck flip off the cruise and try to give it some gas the tac is going wacko up to red-line down to zero ,seems to have a mind of it's own,but I'm not going any where just coastin up the off ramp. Get to the top of the ramp and it finally just shuts off.Try to re-start -turns over great but won't catch.Open the hood everything looks fine.No smoke no smells, throttle is working,no water loss anywhere, no oil leaks.Everything appears to be O.K got it on a flat bed and towed it to Herdons chevy in Lancaster s.c. 125 miles from the house-any body have aany ideas-does this sound like the Opti-crap-It was raining all the way back thanks dennis

 

[vigman]

Any error codes?

Check engine light?
Need more info!

Sorry
Vig!

 

[Yoda]

I don't know much about the C4's but form your description, it sounds like a timing chain/belt slip or broke.. (at least in the older small blocks)
How many miles do you have on it?

BudD

 

[FrankM]

with the tac going wild it is some type of ignition problem possibly including the ecm.

 

[poorboys831]

hi guys-to rare81-belt was tight -no unusual sounds when i tried to restart it -it just wouldn't catch-turned over strong but no fire (i guess)To Vig-no codes, no lights, no check this or that.Thats what has me really concerned,there were no messages....It just to seem to happen so quickly-the backfiring has occurred ,before, when i got the opti wet but after it dried out there were no problems,but even then it started o.k. just ran real crappy. That was about two months ago.The car has over 134k miles on it. I had just figuired out my mpg and it was 26.3 going to atlanta from charleston.so it was running really good.

 

[vettepilot]

I am willing to bet the opti-spark module got a load of water. Been there done that, only I didn't have the good luck of blaming it on the rain. I did it myself several days earlier when I high pressure washed the engine. The opti-spark is not completely water tight, but once the water gets in, it has no way of getting out. The engine heat in that area isn't high enough to get it boiled out before it does it's damage. The other thing that happens is the input shaft to the waterpump begins to seep, leak, since it is located just scant inches above the opti-spark cover, guess where the coolant goes. You got Toyota!
Since the waterpump will have to be removed to get to the opti-spark module, ask the tech to give you his best guess as to the remaining life of the waterpump seal. Then get a new pump anyway, it's cheaper than doing the whole thing twice, and you will, if it isn't replaced the first time.
vettepilot

 

[poorboys831]

hi vette pilot,i think you are right .as things turn out i was just pricing the units before i left on this trip as i have no way of knowing when the opti was last done and was going to get one just as preventive maintenace.Iwas so proud of myself that i followed all the suggestions in this forum ,about getting this baby to run cooler.On the entire trip it never got over 174 on the hiway and monitored it all the time. of course if the opti is the culprit i'll trailor the car back down here and do it myself and will definately check the water pump when i change out the opti.-- thanks dennis

 

[vigman]

AND YOU CAN DISECT IT AFTER

TO SEE IF THAT WAS REALLY THE PROBLEM

( was I shouting...sorry )

Vig!

 

[poorboys831]

hi vig-please don't shout -my wife already read me the riot act about being stuck on the hiway(she has no sense of humor)I'll tell you one thing if you ever break down in S.C.just dial *hp. the state cop had a guy there right away and a trailor ,and made sure we had a ride back to charleston(luckly our neighbor was visiting her son only 8 miles away.Couldn't get much luyckier than that!!!!!

 

[poorboys831]

the saga continues.....I talked to the service mgr. first thing this morning-he informed me they are be backed up and the guy who works on vettes isn't in today(gee has anyone heard that before?).so i went down to pour another cup of coffee and he called me back and asked, what was wrong again? He said he sent 2 guys to push it in and they tried to start it .Well guess what it started right up and they drove it around the lot several times without any backfiring or stumbles.They are going to plug it in and see what codes ,if any show up and call me later.
Are there any codes that will or might show up that will be specific to the opti? so that if that is the problem i can drive it home and replace the opti. thanks dennis

 

[RubyDropTop]

I've never claimed to be mechanically inclined, but my money is on your Opti being bad. If that is indeed the original, the mileage on it is exceptional. I just had the Opti and water pump changed out on my Ruby at 25,500 miles. The symptoms that you describe sound way too familiar to me. Your tack going nuts like it was brings back memories too. When the original water pump was taken off the car it was found that the vast majority of the bearings were gone. The car never overheated or made any unusual noises, but it behaved just as yours did - bucking, sputtering, and shaking like a wet dog. As soon as it would catch when you tried to start it, it would cut out. There are 2 seals within the Opti unit, and over time (keeping in mind that the car is nearly 10 years old now) they degrade and crack, thus allowing moisture to enter the unit. An Opti Spark unit + moisture is not a good combination.

It sounds too typical of tired Opti to me. Let us know how you make out.

 

[vigman]

The Opti will throw 2 codes

( But I don't have my book here)

1) Hi rez signal missing
2) Low rez signal missing





Vig!

 

[poorboys831]

hi vig thanks-i'm waiting on the mech. to call me back -i don't know these people so all the info. i can get will let me make the decision on whether to trust them or not --thanks again

 

[poorboys831]

hi people the saga is almost complete -just got off the phone with the service mgr.and they took the car for a good long drive and guess what! it started again-started backfiring above 2000 rpms and ran o.k. under that point.From all the suggestions here and from him it's time for a new opti & water pump.so it's time to get my buddy with the trailor and head up the road.By the way Vig the codes that were set before the drive =hi rez and lo rez he cleared them and when he returned the lo-rez returned.Are these codes inticative for the opti? thanks guys for all your suggestions and help-it's time to gather the tools and read the shop manual -is there anything real tricky about this operation that i need to look out for? I plan to do the work myself thanks again Dennis

 

[compyelc4]

Maybe you can save a few bucks here! Check the harness to the opti before you go having them pull the thing. Look for corrosion on the opti end of the harness and also the opposite end where it plugs into the test connection point under the passenger side rail cover. There is an outside chance that you have an external problem; not an internal problem with the opti. That is what happened to my '95 at only 16K.

Ted

 

[poorboys831]

thanks guys we are are going to trailer it home on thurs. morning dennis

 

[vigman]

At 134K

Dead opti..... the rear bearing and seal are most likely shot.

1)The seal allowing moisture to get in ( BAD )!

2) The rear bearing allowing play in the opti disc which is what actually does the timing.

3) And remember it's your cap & rotor too!
You wouldn't go 75K on a conventional cap & rotor ( would you????)

It's that time... do it!


And the Low Rez signal is an error code from the ECM... stating it cant resolve/ doesn't get one of the 2 signals opti generated signals.

( The sound of a far away bell in the cemetary ringing...for your opti)


Vig!

 

[96Holly]

You cant go wrong....

Can't go wrong changing an old Opti. Especially if you had problems in the past and not sure of it's history. Money worth spending. I would sugest a good GM dealership opti and waterpump to. You will spend more but they are good parts.

 

[poorboys831]

hi again just ordered the parts (opti & pump) from Vandevere-really good price on the opti-$285.00 not so hot on the pump $145-but it's easier from one place.as i said will get the car thurs. morning and the parts should be here fri. and then the fun begins!!! I talked to a friend of mine about the water problem and the opti he suggested that i use the stuff that his son uses on his distributor when they go muddin in the swamps down here. It's some kind of slimy stuff the spray on that protects it from getting wet. has anyone heard of this kind of stuff? is there a heat build up in this area that i have to be concerned with thanks dennis