clarkinTulsa

I have a no start issue with my 95 Z28.This is continuing from another thread. I have been working on this for three weeks now. It just would not start one day after work. I checked the fuel pressure and it was low. That issue is resolved it has 45 psi in the pump on key position, then goes to 40. I replaced the ICM because two stores said it was bad when tested. No change. no spark. I began testing the leads as instructed on the opti post and all seemed ok. I decided it must be the opti. So I got one from Advanced and installed it and it started!! I was pleased. I did notice a pretty nasty oil leak though. So I decided to get it home to do the process again and change the seal. All this had been in my work's parking lot.... So I got my daughter to help me bring it back home, about 25 min drive, it started and drove but died because the alternator went out. I had a spare at home so got it running again and got it home with no issues. I started it once again to move it around to the back of the house. Then I tore it apart, installed the seal, buttoned it back up and it did start and idled for about 3-4 min then began stumbling and died. I tried to start it again and it did start briefly. During the time it was stumbling the tach was very jumpy. I never got an answer about the ohms for the coil (there are descrepancies one source here says 3000 one say 8000. So I went and bought a new coil and installed it and no change, no spark. So did the opti already go out? I have spent three weeks and $500 (now behind on rent) on trying to start this car... which is my daily driver. I do have another car but it's down now so I'm at my wit's end and cannot get to work tomorrow!!! What gives??? HELP!!!!

slick1hunting

There is a sticky on the top of the page for testing opti's. The ac delco and delphi opti's are the ones with the least reported problems. It would be wise to scan for codes even without a ses light. Checking the opti harness for corrosion or bad wire is also a good idea. It is always advised to loctite rotor screws as well. Checking the coil wire may be a good idea too.


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clarkinTulsa

I have not found anyone with the proper code reader. Yes I have read and followed the readings in the sticky for the opti. How would I check the coil wire? While cranking the engine a grounded wire held close to the coil wire connector produces no spark.

Injuneer

You indicate you has an oil leak, requiring a seal replacement. Which seal?

Did you loc-tite the Opti rotor screws before installing it?

There is free software available for pulling codes. You just need a laptop and a cable. Or use an OBD-I scanner with jumper wires, as shown by Shoebox:

http://shbox.com/1/xraycable.jpg

DTC 16 for loss of low res pulse form the optical cam position sensor does not turn on the SES light, for example.

clarkinTulsa

It was the cam seal. so I have done the install twice now. Laptop and a cable? What sort of cable?

slick1hunting

the cable plugs into your obd port and links to the laptop. Then you can read codes and moniter data. Its a must have if you work on your own car and plan to keep it for any length of time. Can pay for itself in not replacing random parts. To check your coil wire you can ohm it and see the resistance and make sure it has continuity. With the opti harness connector also check for any bent pins.


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Injuneer

Is it possible the cam seal leaked oil into the new Opti before you had a chance to change it? The oil can "blind" the slotted shutter wheel that the optical sensor uses to generate the pulse signal for cam position.

clarkinTulsa

Thank you for the responses. Yes I guess that is possible I would think that these would be sealed better than that. So I will see if I can get this one waranteed... I'll get a meter and chk the readings again before I tear it down again. So it's not some sensor I am overlooking I'm used to working on old school stuff, this thing is a PITA. I've had work done on the rear end, a rebuilt trans etc etc and this boy is broke!

Injuneer

I wouldn't spend money on a new Opti without scanning the PCM for codes.

clarkinTulsa

well after work I removed the old new opti and installed another new unit. It stilll won't start... Any other suggestions? Where do I get this cable? The coil wire measured 2.70

slick1hunting

ALDL OBD1 OBD cable OBDI OBD2 engine codes. That is one place. might find something cheaper idk.


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clarkinTulsa

does this vehicle have a crank trigger sensor?

Scrub88

Obd2 cars 96-97 got crank sensors on the bottom of the timing cover
You said you put a used alternator on the car after first one failed .. I've seen alternators leak ac current into the eltrical systems and starting all types of grimlins

I just mentioned it cause 25 min drive alt failed then car shut down while idling for 4 min after used alt was put on tach jumping all over the place . This might be a voltage supply problem or charging system malfunction giving the ignition and distributer problems

Injuneer

It measured 2.70 "whats"? 2.70 ohms, 2.70 on the 1000X ohms scale?????

The crank sensor was added 96/97 years as noted above, but it's only used to detect misfires. Has nothing to do with whether the engine runs or not.

The engine timing (spark and sequential injection) is derived from the cam position sensor, which is the optical device in the Optispark distributor. A problem with that sensor will set codes. One of them will shut down the fuel system, and prevent the engine from starting, and does not set a code. Did you check the Opti harness connector for corrosion and/or bent pins?

clarkinTulsa

The new opti I installed yesterday came with a new pug tail connector that connects up by the throttle body. I set the meter to ohms it have me the reading. Someone just said to check the ignition switch itself...