Lifter preload incorrect is my stab in the dark guess.

New Optispark doesn't mean good optispark. Could also be an oops by the programmer. What emissions stuff was taken out?

 

All emission were removed supposedly.
spark plugs are fouling if we run it too much.

any ideas?

 

Some of the cheaper opti-spark units are junk.

 

Get yourself an obd1 cable for computer and download scan9495, you will be able to see what codes are throwing check engine light on, plus monitor everything to see what’s happening, once you have cable you can also get adjustments made to the tune! I want to say the red river is the cable i have for my 94 lt1

 

Sorry, not red river,,, red devil

https://reddevilriver.com/aldl.html

 

Update;
The painless kit came with obd2 even though 94 roadmaster was obd1. We are not able to get a code from code re

I rewired It obd1 style and to fit obd1 port, the check engine light stays solid.

many suggestions?

 

What year is the pcm? If 94-95 it’s still
Obd1, 95 was obd1 with an obd 2 port. So you need to get an obd2 cord for computer, and get that scan9495 I mentioned, it’s a free program! It will putll your codes, most readers do no read the obd1 stuff with obd2 port! Without knowing your codes, everything is a guess
I would also suggest joining ltxtech forum and picking their brains! Also download wiring diagrams from Shbox.com. Those two sites helped me to no end when I did my lt swap into my jag

 

Thanks, I’ll check those out.
Let me confirm; it is 94, but painless sent an obd2 port….but confirming, no obd2 scanner will get a code, correct? Because it is an obd1 computer, correct?
So why isn’t the engine light flashing a code when I hook up the obd1?

 

Post the part number of the ECM. Late 95 LT1 they started switching to full OBD2 before the 96 model year.

 

We have two computers; so me with emissions deleted and one without for testing.
This one is from a 93 trans;Service #, 16188051,
I pulled it out of the car,

the other is a 94 roadmaster computer, I’m pulled that one too.

map given that, for certain I shouldn’t be trying to read it with obd2, correct?

mom sending my son down to get a new coil this morning to try to fix running, that’s the only part i haven’t replaced…

 

Obd2 scanner will not read obd1 codes, and 94- 95 will not do the obd1 code flash with check engine light. Obd1 with an obd 2 port is generally known as obd1.5, but still uses the obd1 code, 93 computer is an ecm or engine control module, as it doesn’t control transmission, 94 and up is called a pcm power train control module as it does control trans, also, 93 cannot be reprogrammed via a flash like the 94 up, it will require a new chip being installed!

 

We’re only using the 94 computer.
So if the light doesn’t flash, how are the error codes obtained?

 

Via an actual obd1 scanner for gm, or you need scan9495, which will not only scan your codes for you, let you reset them, it will also create a data log that can be read by some others and they will be able to tell you exactly where your issue lies, could be as simple as a failed fuel pressure regulator letting fuel be pulled through the vac line directly into manifold.

 

Here’s a screen shot from scan9495, as you can see it actually monitors just about everything

 

Where can I obtain this program and hardware needed?

 

Hardware can be found here
https://reddevilriver.com/aldl.html just make sure you order the correct cable, I believe it’s the 16 pin
And the software is here…MediaFire

 

When we plug in the obd1 ready, the fan and fuel pump turn on, and check engine does not flash.

I ordered the cord for the pic, but I would love to be able to read the codes

 

Did you get the cable and software???

 

It hasn’t come in yet.
We have it running/driving. Bit idle is erratic and stumbles over about 2200 rpm.

No check engine light.

tps? Opti? Maf?

 

My best guess would be a vac leak or exhaust leak, but without scanning it there is no way to tel from a distance, I would also suggest downloading tuner pro, that way you can actually look at what idle is called for, and you can also make sure that emissions items are deleted so they won’t cause a check engine light! It’s also a free program you will
Also need eehack or eeflash to download and upload your tunes, again all free

A quick test of the maf wolf be to unplug it, and see how car runs, unplugging it put the computer into batch fire mode ( like a 93) see if it clears up, but I doubt it will

 

Now we cannot start, and light tester lights up when touched against frame…

 

You need to explain this some as to how you are testing. I’m presuming you mean a continuity tester with a lighted probe, see the link to what I think you mean?

Amazon.com: Heavy Duty Automotive Circuit Tester, Premium 6-24V Test Light with Extended Spring Test Leads & Sharp Piercing Probe, Circuit Voltage Tester with Replacement Indicator Light for Car/Vehicles : Automotive

Buy Heavy Duty Automotive Circuit Tester, Premium 6-24V Test Light with Extended Spring Test Leads & Sharp Piercing Probe, Circuit Voltage Tester with Replacement Indicator Light for Car/Vehicles: Electrical System Tools - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Bogie

 

Checked all grounds, all wires/connections to coil are good.

When it’s trying to start, it stumbles every few rotations, not sure what that means, but it’s not just tuning over and over, it’s like it hiccups, but it’s not a backfire.

 

With computer logic and sensors involved obviously the range of possibilities is quite large especially since the program was touched by a third party the probabilities of logic or sensor incompatibility is high.

That said, this does sound strongly of a distributor problem. This is common on this engine inclusive of current day replacements. These days the fact that something is new even from a major name brand does not assure any better reliability, serviceability or compatibility as any off brand from EBay. That is just the way it is. All the major brands like Comp, Edelbrock, Holley, MSD as examples are part of a Wall Street private equity investment corporations. These companies are not run by their founders or subsequent family they are all held by background investment corporations that have only return on investment in mind. Most everything is sourced in parts or in whole from China, India or Indonesia. The classic that smashed into an openly public argument was the battle over low height floor jacks when somebody saw that the Harbor Freight and Snap-On were the same jack in different colors. The cost difference being 650 dollars vs 200 with some assembly required. Both come out of the same Chinese manufacturer. Snap-On’s argument for the 450 dollar difference is they do the final assembly in America. All of this stuff arrives in America kitted as your government offers huge tax discounts for items arriving from overseas as not fully assembled.

Anyway that leads to your new distributor whether having a know domestic brand name on it of some import brand or unbranded from the inner details to a complete ready to run part it’s more likely to be imported than not. A common problem is the distance in performing tolerance whether that is in electronics with ohms, henry’s or capacitance or whether in physical materials dimension and specification of type and purity when compared to the OEM which even if imported is being made and hopefully inspected as conforming to the original engineering specifications. When you step away from OEM branded parts these are the risks at compatibility levels you run and in your case compounded with a customized computer program.

A possible trick with these engines could. And I emphsize COULD! I haven’t tried this trick maybe somebody out there has, but that would be to rewire for the use of the 87-95 TBI distributor. This would require using the GMPP LT1/4 4bbl intake and modifying it to use port injectors and accepting the LT1/4 throttle body. This isn’t technically impossible but it is a lot of work.

Bogie

 

 

Still won’t Start, any ideas?