Cam's maro

I put together a game plan to try. First off check to make sure the connections are in fact plugged in tight (Everything was labled as it was unplugged, but if somehow two injector plugs were inadvertantly swapped it wouldn't matter with batch fire correct?). I am wondering if perhaps I left off a ground strap from the engine. Would that create electrical demons explaining whats happening? I want to check out the plug wires to confirm they are routed properly. Also, I am thinking it's possible that the copper wire I used as a jumper in the ALDL may have been to large of a gage preventing it from making contact. I am going to try it again with a paper clip and see if I can get some codes. I want to check the output of the alternator. If it isn't charging the battery properly maybe there is a lack of voltage or if the regulator is allowing a overcharging of the system. If the ICM is bad it would prevent the engine from running, not causing a miss correct? So that shouldn't be it. I have the testing procedure for the opti spark out from shbox's web site. Hopefully that is good. It was fine before we started this project and we did our best to keep it safe and dry while it was out of the car. In regard to the idle surging so bad, we started the car without the air intake which meant the air temp sensor was unplugged. After putting the elbow back on and plugging that in the idle is much better. I shot a short video of the car running to show the symptoms but I do not have the option to post videos for some reason. Maybe by Sunday I will have found something. Anything else I should try?

Injuneer

Correct, batch fire has 4 injector plugs on each circuit, cylinder number is not important.

I would try to replicate all the stock ground connections, particularly the one from the driver's side head stud/ICM bracket to the chassis. Other than that one, I can't list them, but there are others.

ICM could probably cause erratic engine operation, not necessarily total shutdown, dependant on temperature/heat soak problems.

IAT and MAP are critical to speed-density.

Just keep working on pulling the codes.

Cam's maro

Today I went back over all the connections at the IAC plug, ICM, plug wires, ground connections, injectors plugs, and all the plugs at the ECM. All were good. I used a paper clip across the A and B ports of the ALDL plug, the ALDL will not go into diagnostic mode. Port A and B have 4.97 vdc measured with a multi meter. If I measure from B to ground it is still 4.97 volts so I assume the ground circuit is correct. I put a meter across the coil and measured 7.97k ohm at all four terminals. At the opti harness key in the on position I read 4.76 vdc from A to ground, B was 4.76 vdc, C was 11.93 vdc, and D was 44.2 ohms resistance key on : .3 off. Across the ICM I read 12 vdc at A to ground, C had 3.52 ohms key on and .2 off, D was 12 vdc, but while cranking the engine B had zero volts. All the fuses, including the 10 amp ignition fuse, checked out ok. One last thing that is peculiar is that when the key is on and the engine is not cranked the fans will come on. I have the stock opti I removed and replaced with a MSD unit last year due to it breaking down over 5500 rpm. I want to put the factory opti back on and see if that makes a difference. I know that the opti gets a lot of undue accusations by everyone, but after getting no voltage from B to ground at the opti plug while cranking the engine I suspect that for whatever reason it may be flaking out. I can not explain why the fans come on or why the ALDL plug is unresponsive. Any thoughts as to my tests results or conclusions?

grabbem88

Is this with stock computer without chip??

No diagnostic read out and fans automatically come on

Got a back up computer???

I know these things can take a beating but its possible

Cam's maro

I don't have a computer but I can remove the custom chip and return the tune to stock. Perhaps something is wrong with it. It's much easier to do that than it is to pull the opti off that's for sure. One of the first things I did yesterday was to remove the computer and double check all the plugs were seated properly. It is a common link to all the problems. A little fore thought would have been good there. Thanks for the in put.

Cam's maro

Problem solved hopefully. I removed the chip that holds the custom tune and installed the factory chip. First thing I noticed was the fans did not come on when the key was turned on. Second thing was I could pull codes now jumping A and B together. (No codes were there). And lastly, when I started it up it would rev freely and had throttle response. With the cam it wouldn't idle which I expected. Monday I will be contacting the tuning company and see about getting the chip corrected. Thanks to everyone who helped out with your advice. One last question: with this cam It makes considerably more lift, duration and overlap than the factory piece. How does the Knock sensor understand the difference between the cam profile and a Knock?? Thanks again for your help

Cam's maro

This will be the last post on this issue. I spoke to my programmer and before I could finish describing the symptoms to him he chimed in and rattled them off to me. Seems he has heard of this problem before. I inadvertantly held the factory chip upside down while plugging the aftermarket piggyback chip into it. This made it impossible for the computer to interpret any engine data or to make any tunning adjustments. So, if anyone has similar issues in the future, be sure to look for the correct orientation of the chip.

grabbem88

I will since I've been wanting a chip for mine

Hooker LT's hooker Y gutted cat flow master
And my cai and tfs elbow. Other than that just coolant bypass and crank underdrive pulley

So I'm bumping only to 24lb injectors and tune hopefully that will net me 270rwhp on a 240k motor lol

Cam's maro

If you want a chip I recommend contacting PCM of NC and ask for Mark. He's a good guy to talk to. 704-307-4227 PCM Tuning, GM Performance