[size=16px]Hello I am having an issue with my car It's a 96 camaro with 50k miles no modifications at all bone stock. It had been sitting covered up for about 6 years. When I first tried to start it up I ended up replacing the fuel pump. After that it kept throwing codes for little stuff mostly sensors and tune up things. Everything I have replaced is OEM. Ignition coil and module. Optispark, plugs wires, pcv valve, brakes, thermostat and both sensors. Air filter, vacuum hose, fuel filter, oil and filter. I'm sure I'm leaving something other small stuff out. Mass air flow sensor and pigtails to Ignition control module as well as to the mass air flow sensor and Ignition coil those are new. The car was running good until that Optispark went out so I ended up replacing it with a autozone one that seem to make it run rough. Took that off replaced it with a Delphi that i found by luck. During that time before the Delphi I noticed the car had a slight rough idle as I thought it was the aftermarket Optispark from autozone. I put the other opti on and it ran rough still intact even worse as it should not. I haven't even drove it barely at all since I've done all this stuff. So then it dawned on me that the autozone Optispark wasn't the issue something else is. The car acted like as if it wasn't getting any gas and was throwing codes again like in reverse of everything I did. It threw the mass air flow sensor that was new replaced that again OEM and it threw the ignition coil I replaced that again OEM. Then the last code was the p01351. So then I went had the module tested its fine. The car finally cut off and will crank good but no start no spark. I checked all the wiring and measures grounds, continuity and power of everything that has been shown in the forum shoebox. I have no idea what it is can anyone help or have any clue? Is it the PCM? That's the last thing I can think of beings it was throwing code after code again in reverse. No one here really works or wants to work on the Lt1s and people who have" mechanics" are stumped. With 50k miles I understand that it was sitting for a long time but it can't be anything that crazy. Oh and the optispark harness is good the signal and power as well as the spark plug spark it's getting no spark I tested that out. Please help if you can I'm worn out on this. I've probably missed something so any help is greatly appreciated. [/size]

 

Have you considered the possibility that P1351 is set by a problem with the white wire from the PCM to pin “B” of the ICM?

Here's the wiring diagram:

http://shbox.com/1/1996_ec_03_ign_system.jpg

Here's a way to check. Scroll down to “ICM Harness”:

4th Gen LT1 F-body Tech Articles

And a quick question - when the starter is cranking the engine, does the tach needle move up (roughly) a couple hundred RPM.

 

I didn't check if the tach needle moves up but I will now. And on the pcm connection when you say white wire there's a pinkish looking wire and then there's the orange wire. I tried to look at the link below but for some reason it isn't loading. I may have seen that already. I have checked all the wiring but I'll do that specific one that you say. So it's the white wire from the black connector or the other one and then to pin be on the icm. Am I checking for power from one to the other on DC voltage?

 

I checked the Tachometer just now it doesn't move.

 

The tach needle not moving at all indicates the PCM isn’t receiving the Opti low resolution signal. To double check, measure the AC volts to pin “B” on the ICM while cranking the engine (per linked procedure above).

Also check the Opti harness following the procedure in the link above. That doesn’t check the Opti, but checks if the PCM is supplying the 12 volt power, 5 volt references, and ground that the Opti cam position sensor needs to function. Does the current Opti have a socket for the “short” Opti harness from the gray connector on the bracket on the passenger side of the intake manifold to the Opti? Or is the Opti a newer style with the harness permanently attached to the Opti case? The harness connector at the Opti can corrode and interfere with the contacts.

 

I finally was able to look at what you sent me thank you for that. Its actually what i went by before when I was checking all the measurements, voltage and continuity everything seem to check out good. But I will double check it all again. And I tried the crank to see if the tachometer moved any it didn't. What does that indicate to your knowledge or does it point to a possible solid solution?

 

Here's a simplified version of the wiring schematic. It's from a 95, but the main difference is that the 97 has a single coil connector, and 95 has a "siamesed" double connector.

Note that in this GM schematic, the order of the pins on the ICM connector is shown as "C A D B" when in actuality the order of the pins on the connector is "A B C D". This is where you find the white wire, and the ICM end you need to check - circuit "423 WHT". That's where you check for a range of "1vac-4vac while cranking". This is the only time you set the meter to AC volts. All the other tests are measuring DC volts. The white wire isn't really an AC circuit, but that's how the pulse to fire the ignition, riding on a 5 DC volts reference can be measured, per the factory service manual.

No AC volts on the white wire = no spark at the plugs.

No low resolution pulses from the Opti to the PCM = no spark at the plugs

http://shbox.com/1/95_ign_system_schematic.jpg

 

where did you get the Optispark from?

 

Injuneer You put me on the path i needed! Its not fixed yet but after when you told me to check the tachometer I did and that made total sense about the optispark. Got it from ebay it was a refurbished one. Well after I checked what you said something was off on voltage so I thought in my head I had another old optispark that actually the car would start with that one but only for just a few seconds so to confirm it is the optispark I put the old one back on. I didn't put everything back together just the optispark back on the belt pulley and coil and module as well as the coil plug. I put it on and tried to start it and it did start but cut right off because that one is bad. But it eliminated the issue that this "newer" optispark is not good so I'll have to get another one regardless. Thank you for getting me on that path. My next question would be where can I get a good optispark that is under $400? I've read and read posts but nobody seems concrete when it comes to this subject. I need to get one and then when I put that one on I will 100% confirm everything is good but I'm confident it the outcome will be. Thanks to you guys if there was no forum like this people would probably give up your knowledge is fantastic.

 

You can't get a “good” Opti for $400. The only reliable source at this time appears to be Petris. Hold on to your wallet…… well only $440 for a 95-97/F-Body.

https://petrisenterprises.com/collections/frontpage

 

Hey i order the one kind you sent me the car fired up thank you! But now I'm having another weird issue so the car is idling rough shaking I got the p0100 code for the MAF sensor. I checked all the wiring getting ground and 12v to both wires. So I got a new pigtail wired that up and the code went away. Now I'm getting the P0300 code and it still runs the same idle rough shaking and acting like it isn't getting gas. Couldn't this also be an 02 sensor sounds like all the symptoms. And I have not replaced any of those. Or could it be the alternator I know that will end up having to be replaced because it was making a noise but wasn't dying. I'm not sure If any of those could cause that code and the mass air flow sensor code. I suspect 02 sensor but idk what do you think?

 

check this thread

https://www.camaroz28.com/forums/lt1...-fixed-612879/

 

hey Injuneer I did get that opti it's good and after i got that the car was still shaking and acting like it wasn't getting enough gas. I then got newer spark plugs that helped but It was still sluggish and still shaking. I checked up on the MAF sensor that thing was actually bad I just replaced that yesterday because it threw the p0100 code that codes gone and the p0300 multiple misfire I fixed with the spark plugs. I'm down now to no codes hardly any rough idle tiny bit of shaking and tiny bit better at the getting gas/power issue. Whatever it is it's almost fixed. Now I'm really out of ideas and puzzeled. So it's doing kinda what it was but lightly shouldn't be doing any. Still can't step on the gas and feel the tight power it's a little hesitant and a little shaky rough idle but no codes. Please help do you think it's something to do in that area of the mass air flow sensor?

 

Are you sure the plug wires are tight on the plugs? Did you reuse the metal shield that were on a few of them?

At any point have you cleaned or replaced the fuel injectors? Is the fuel fresh? If it was sitting unstarted for 6 years, fuel could be a problem.

 

yeah I only had to replace 1 injector and I cleaned the tank when I put in the new fuel pump. Also ran some good stuff in it. I didn't see any meta shield when I was replacing the wires. I went back to check to make sure they were on tight. When I did that I actually got 2 wires mixed up and when I started it it threw the p0303 code but I fixed that. It'd just kinda shakey and acting as if it's not getting enough gas. Hesitant when you step on the gas. No other codes I'll go back and check the wires again. Is it possible it could be the fuel pressure regulator?