shoebox

Since the pump is electric, the engine does not have to run.

Injuneer

Experience indicates that the only reliable Opti is the GM (Delco or Delphi) unit. Everything else seems to be a real crap shoot - off brands might last for 10 years, might last for 10 minutes, might be bad out of the box. And all of them need the rotor screws tightened with Loc-tite, or the rotor may fall off.

MgodzNightwoop

thanks for the info. i didnt know that. im starting to think its an opti problem. and if it is. ill go with the gm unit. any idea of where i might get a reasonably priced one? i know i paid $225 plus tax for the off brand one i got. my next day off work is friday. so ill try the fuel pressure gauge and the spark tricks. one i got some more info ill let ya know. and thanks again for all the help!

shoebox

I always check Amazon for price. They are usually the cheapest ($375.74 right now) with free shipping.

blown94

Fuel pump is electrical, you should get minimally about 40 psi at key cycle, i cant remember exactly, but i know running with the vac off the pressure regualtor i believe you should have 56psi running. Roughly 35-40 psi should run the car unless you have an injector issue. Check spark, fuel pressure, and injector pulse (use a test light). If all seem good do a compression check on ALL your cylinders (easier said than done on an LT1), but it HAS to be done to verify every cylinder is up to par.

Oh and like has been said, i bought a cheap ebay opti, installed my msd rotor, and had no issues with it. Ive bought remans from local store that were junk, its a matter of luck i think. Someone called thepartsladi used to sell optis cheap on ebay, dont know if she still does?

shoebox

Vacuum line off the regulator should be 41-47 psi-not 56. Idle pressure with the vacuum line on might be 6-8 psi less. Thepartsladi has been defunct for years.

MgodzNightwoop

ok guys. i pulled the coil wire off the opti. had my g/f bump the key and it shocked me. my guess is....its gettin fire. but when i did the same thing to a spark plug wire. nothing. so my guess is the opti went out again. my question is this. before i go tearing down the front end of the motor. is there any sensors or fuses that would cause the opti not to work? shoebox. i checked around. u were right. best i can do for an ACDelco opti is $375.74

Injuneer

If you are getting spark at the coil, the optical section of the Opti is working fine. If the spark from the coil is not getting to the plugs, it would indicate a problem with the contact of the coil wire in the Opti cap, a rotor that has come loose or lost it's contact, or a damaged Opti cap.

I would retest for spark from the Opti by using an insulated plier to hold the wire close to the block, and observing the spark. Do the same with several spark plug wires. You are dealing with upwards of 20,000 volts

MgodzNightwoop

there isnt any spark at all coming from the plug wires. so im gonna go ahead and pull the opti off. and check it out. but according to what ya'll are saying. i just need to replace it with a GM unit.

shoebox

Obviously, you can replace the whole unit, if that is what is required, but if your issues are only with the cap and rotor, you can just replace only those. The mileage on the opti and what you see when you get it apart might help in making that decision.

blown94

Yeah I would pull it apart and take the cap off before you buy anything. You may just need a rotor. Cheap rotors have been known to self destruct or as he said, just come loose and fall off. Open her up and see what you got. Maybe youll get away with a cap and rotor kit!

MgodzNightwoop

thats what i was gonna do. but in true granny fashion. my granny wants the car fixed as much as i do. so without me knowing. she went a found the ac delco opti and bought it. so is there anything i need to do to the opti before i put it on the car?

Injuneer

Loc-Tite the screws that hold the rotor on.

MgodzNightwoop

alright. so i tore the front end apart. put loctite on the screws. and then put the car back together. the car is slow to crank. but it actually does crank. it has a "rough idle" to say the very least. it runs like its hittin on about 3 cylinders and then after about 3 seconds. it dies again. so im half way to where i wanna be. but what could be the problem? ive double and triple checked the firing order. checked the plug wires and made sure all the wires are secure to the plugs and opti. WHAT AM I MISSING????? any comments will be greatly appreciated!!!!!!
Thanks,
Jared

Injuneer

Are you sure you have the cam dowel pin correctly indexed to the back of the Opti?

Courtesy of Shoebox:

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

You'd be amazed how many people manage to screw that up.

Why not add a "Signature" so people know the specific details of your car, and don't have to go back to the first post in the thread to find basic info like the year?