LTX and LSXPutting LT1's, LS1's, and their variants into Third Gens is becoming more popular. This board is for those who are doing and have done the swaps so they can discuss all of their technical aspects, including repairs, swap info, and performance upgrades.
Welcome to ThirdGen.org!
Welcome to ThirdGen.org.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!
For those of you who don't know, i swaped in a 94 lt1 into my 91.
The other day i tried for my first start and nothing. I smelled all my spark plugs and they all smelled like fuel, so for right now im not worrying about that. I am not getting any spark. I am not getting any spark at the coil either, i tested this by doing the plug wire trick right from the coil and nothing.
Now i tested everything for power and everything has the proper voltage
I did this opti and spark test http://shbox.com/1/4th_gen_tech2.html#opti_test. and discovered i am not getting any AC voltage when the motor is being cranked. Now i realize this means either i missed something retardedly easy right infront of my face, or that the opti, pcm, or any of the wiring between is bad.
The opti is a brand new ac delco unit. the opti harness is off the original motor, i tested the resistance on all the wires and got 0 ohms on all 4. The wiring harness is brand new from speartech. The pcm is off the original car.
I talked to vince @ trifecta cause he did my tune, and he said his tuner can double as a scaner. I tried to pull the codes from the pcm and it gave me an error message. I tried this 20 times 20 different ways and i always got the same result. However his tune uploaded fine to the pcm.
I need to know if there is a way to test the opti for a pulse in the wiring BEFORE it goes through the PCM and back to the ICM. I cant eliminate the pcm or opti based on the test i ran it could be either one.
Anyone has any advice that would be a great help.
Thanks
__________________ 1991 Z28 Engine: '94 355 LT1, GM hot cam, 1.6 RR's, Ported Heads, Dyno Don's headers, #30 SVO injectors, stock internals with skirted pistons. Drivetrain: '95 T56, pro 5.0 shifter, hayes clutch, Stock 10 bolt with 3.42's Suspension: LS1 front brakes, Spohn SFC's, hot part LCA's. 265/40/18's up front and 275/40/18's out back on 18x9.5 c6's 335RWHP 339.8RWTQ
Have you had the ICM tested? I assume you checked all the ignition grounds. Have you ohmed out the coil? These are things to check if you haven't.
__________________ 90 Firebird Formula (Stephen)Sold!
LT1/T56(formerly 305TPI/T5), 355 with LE1 heads and cam, Hooker 2210s, 1le Brakes, alston subframe connectors, Spohn tubular control arms and panhard rod, Jegster torque arm, Richmond 4:10 gears and all new interior and paint.
Working A/C!
My car on Cardomain (updated 12/27/06).http://www.cardomain.com/ride/2415999/1
92 Oldsmobile Silhouette (Agnes)
62 Galaxie 500 An old friend that found his way back.
i have an aftermarket harness from speartech, and there was only 1 ground on the harness and it is on the firewall along with all the other grounds and the chasis to block ground.
Have you verified that all of your grounds(black/white stripe) are good grounds? There was also a bad batch of AC Delco optis a while back. You might want to also look into this.
I will verify all my grounds, and the wires between my pcm and icm, and if those are all good i am going to send my pcm to vince @ trifecta to have it tested. I understand these pcms rarley go bad, but ive never witnessed this on a running car and everything else is new..
I checked all the wires, they were good. I pulled the codes again and it looks like 42 was intermittent. I got the wonderfuly exciting code 16. Brand new opti is no good. that really sucks. Is there ANY reason other than the opti i could get this code? Like faulty plugs wires or anything like that?
i got my opti from thepartsladi on ebay and i was informed to just send mine back and he would replace it with a new one. But i found this that might help me narrow it down a bit:
Quote:
Here's how to test the low res signal from the opti. It's about a 3 minute test using a voltmeter (VM)
1) disconnect the test connector at the manifold.
2) turn ignition on and use a voltmeter to check the voltage on the red/black wire on the PCM (firewall side) side of the connector
3) less than .5 volts - faulty PCM or shorted PCM connection to test connector
4) 4-6 volts - turn off ignition and go to step 6
5) over 6 volts - short to voltage on low res signal circuit from pcm to test connector
6) reconnect test connector and remove connector at opti
7) turn ignition on and probe the red/black wire connector with the VM
8) less than .5 volts - short in harness between test connector and opti connector
9) 4-6 volts - faulty opti connection or faulty opti
10) over 6 volts - short to voltage on low res signal circuit from test connector to opti
