94 z28 A4

My dad was driving his 93 z28.. Was in 2nd gear fixing to shift to 3rd and all of a sudden it just shut off. He let it coast to a stop but before he pulled it off the highway (car is shut off) it backfired. Not real loud. Tried to restart it but all it would do was roll over. Just like its not getting fire. He bought a new coil and wire but still no fire. Help would be greatly appreciated. The opti was replaced like 25k miles ago so I don't think it would be that. He did see that the plug wire on the coil was arching that's why he replaced that wire and the coil. He said the fuel pump still primes when he turns the key. Could it be a clogged fuel filter, maybe a ground wire came loose somewhere? If it was a ground wire then it prob wouldn't even try to turn over right? Could it be a sensor? Please help ASAP! Thanks in advance!

cprmn14

What brand is the opti? Wouldnt be suprised if it took a dump. I had a new GM model with 0 miles and it was a dud. Never know. Id check fuses aswell.

joelster

Sounds like the rotor broke apart. If you have power coming OUT of the coil, but none at the plug.....

One of the most important things you HAVE to do when replacing an opti-spark, is to remove the rotor bolts and then loctite them in place.

ahritchie

iTrader: (1)

I say your ICM possibly took a dump as they like to do...or the opti which is the number one suspect for those sort of symtoms as mentioned.

94 z28 A4

Thanks guys for the replies... He is gonna try to pull the codes later. It's getting fuel to the motor but he is gonna hook a fuel pressure gauge to it just to see how much pressure it's putting out. Just praying it isn't the opti. If it is the opti what is about the average price a mechanic charges to install it?

shbox

I'd bet on the opti. Don't know about shop charges. Mine never goes to one. Parts and labor I would expect $800+.

leadfoot4

iTrader: (1)

If you still have the OE front pulley on the engine, why take it to a shop? The pulley is a 2 piece affair, designed to allow the Opti to come off without much hassle. The bolt pattern of the hub is asymmetrical, so when you unbolt the outer ring, and rotate it into the correct orientation, the "ears" of the hub provide just enough clearance for the Opti to slip off. NO WAY I'd bother with a shop....

ahritchie

iTrader: (1)

It will cost you an arm and a leg and maybe your first born child if you go to a dealership I know that much....especially if they charge full price for a GM opti ($450 or something crazy), I believe it's something like a 7-8 hr "book" job (really takes them 3-4 hours if that) anywhere from $900-$1200....**** is ridiculous. A private shop would probably cost about half of that.

Better yet, do it yourself or ask a mechanically inclided friend to help out and supply the beer It's not quite as bad a job as everyone makes it out to be and you'll learn a lot! Two amatuers could easliy do it in an afternoon, just take your time.

jeepbeast

Happened to me one time on the freeway. It turned out to be a bad coil...msd and it was brand new. If not coil probably opti???

94 z28 A4

He has a friend coming over to look at it.. The guy use to work on lt1's a long time ago and replaced several opti's. He's a good friend so he prob won't hardly charge a thing to put the new one in. He is retired and has nothing else to do. Anyways... Do y'all happen to know what the fuel pressure is supposed to read when you check it with a manual gauge at the fuel rail?

shbox

41-47 psi when you prime it and same with engine running and vacuum line to the regulator removed. Everything connected, idle pressure will be much lower.

94 z28 A4

Got the car fixed... It was the cap and rotor. It came apart on the inside.. Put a new one on and runs great now. Thanks everyone for your replies. Thank you joelster

joelster

No problem! At least those parts are cheap, just a lot of labor to replace them.

94 z28 A4

Yeah they were pretty cheap and he actually didn't charge much for labor. I was surprised.

pkincy

iTrader: (1)

First time I changed one it took 8 hours of me taking my time.

The last one I changed took 90 minutes. Practice makes perfect.

Good time to put in a new WP also.

94 z28 A4

Yeah we went ahead and put a new water pump on also along with a new t-stat