cuts out @ 4600 rpm, I'm thinking its the LM

[boboli]

I have an 86 glh with 87 electronics. I added a lot to the car and decided to get a cal done for it. I got a T2 LM and had Shelgame make me a cal. The problem is that the car won't rev past 4600 rpm. It did this several months ago, and I thought it was the staging limiter. Shelgame sent me another chip without the staging limiter, and that seemed to fix the problem. The car then sat while I worked on putting a 523 in it. I have the trans done and when I went to drive the car, the cutting out has returned. If you rev the car ( sitting still or driving, boost or no boost), the car revs fine to 4600 rpm. Then the car cuts out, flashes the cel very quickly, and the rpms drop a few 100, then revs freely again till it cuts out again.
The Lm in this car has never seemed to be right since I got it. It would not display codes other than 12 and 55. When I drove the car recently and the problem manifested, it actually would display codes, and there were a lot!
44 battery temp
45 overboost- ? the overboost is turned off on my cal and the cal is good to 29 psi (which I was no where near)
46 charging voltage high - I do have an external regulator on the car
47 charging voltage low
51 O2 lean- I have My LM1 WB connected to the LM and the LM1 doesn't display any problems
52 O2 rich
53 internal Lm problem
54 fuel injector sync
55
Before I got this LM/cal, I had a mopar stage 2 cal and I had no problems with it. All these issues seemed to have come about after i got this combo. I unfortunately don't have anymore T2 LMs. I do have 2 87 T1 Lm's, but they are not socketed. A year or so ago, I took apart the entire wiring harness and went through it wire by wire to make sure everything was good, so I don't think the harness is an issue.
I have read about intermediate shaft issues causing a cut out, but I just don't think that is my problem, since this started when I changed LMs
Any advice would be appreciated.
Should I socket one of the 87 T1's and see if that fixes the problem? Or is there other things I should look at first.

I also did try switching PM's and that changed nothing

[turbovanman²]

Try another LM, sounds like a bad LM, been there, got the badge.

[roachjuice]

Bad connection somewhere. Been there before. Throwing random dumb codes. It's one of those wires that you had to swap on the lm plug I bet. Check and double check them all. With the car running unbolt the lm from the car and wiggle wires till it dies or acts strange. Took me a week to figure out it was a loose wire.

[boboli]

I found a place in town that had the 28 pin sockets and I installed it in 1 of the 87 T1 Lm's I have. It still does the same thing, cuts out and only shows code 12 and 55. I even unplugged the temp sensor and it doesn't display a code for it. I tried wiggling a few of the wires on the Lm plugs, but nothing seemed to happen. I will try it some more tomorrow.
Anything else I could look at?
What are some other symptoms of a bad intermediates shaft. I was having detonation problems starting at low boost (10-12 lbs). Just wondering if this may be a symptom of a timing issue. To fix the detonation, I had to retard the ignition timing, run better than 91 octane, and Shelgame even lowered the knock threshold in the cal, but it still likes to do it some times.

[BadAssPerformance]

Random ideas...

bad hall effect pickup?

Loose shutter plates in distributor?

worn intermediate shaft?

[DaveSkrab]

Check the cam timing, sounds like it might be a tooth advanced. Mine wouldn't rev past 4400-4600 and would pull 14* of timing due to knock, while under load. I found the cam timing incorrect while changing out the worn I-Shaft and Oil Pump.

[Orangetona]

Im also calling the LM bad here...with the amount of codes, it seems about right.

[boboli]

i tried a few things this afternoon but nothing fixed the problem
1.I played with the cam timing, by moving the belt 1 tooth either way and also using my adjustable cam pulley to add 12 degrees. None of these made a change
2. changed hep with a used 1 I have, still no change
3.tried swapping in my 1st shelgame cal, this still has the staging limiter on it but the car acts exactly the same.
4. i did find 1 wire for the AIS that broke off when I was swapping LM's. I replaced it but still runs the same

I noticed when I had the Hep out and I tried turning the distributor by hand that you could turn the rotor a couple of degrees without even seeming to move the intermediate pulley. I did replace the distributor a while ago, so the shutter is not the problem. Could this be a sign of intermediate shaft wear? How much movement should there be? I know on the ford 2.3 turbos, if you swap distributors you better swap the gears or the new gear on the old intermediate shaft is a recipe for disaster. Could this be a possibility for dodges as well
I am going to try some more tests later tonite. I want to see if the ignition is cutting out. The plugs are dark and this has never happened before

[boboli]

Tried a few more things. i have 2 ignitions on the car, an aftermarket and the stock coil. I swapped them and still no change. decided to see how much the timing mark wobbles with the timing light. I was hoping that at higher rpm's with the temp connector disconnected, this might show if there was too much slop in the intermediate shaft, distributor timing. Even at 3k rpms, there was barely any variation. Maybe 2 degrees max/total movement

I decided to see whether the ignition or the fuel was cutting out. The plugs were showing rich so maybe the ignition.
When I rev the car to the limiter with a timing light attached to a plug wire, the ignition keeps flashing smoothly even as the car cuts out.
I then went into the car and as you rev the engine, the wideband afrs are in the 13's, but as soon as you hit the limiter it goes to 19, then 21, then 24.
Obviously something is cutting out the fuel. My in dash fuel gauge doesn't show any problems, no pressure drop. It seems like it is hitting fuel cut out.
Any ideas?

[boboli]

drove the car and watched the fuel pressure gauge. At 1/4 to 1/2 throttle The fuel gauge climbs to 62 psi right as the fuel cuts out.
When I got home, I checked the plugs and they had cleaned up.
Some one suggested checking voltage all the way through the rpms. With my external voltage regulator I get a steady 14.3 volts from idle to cut out
The 523 I put in seems to have a lot of the internal noise associated with them, so I tried unplugging the knock sensor to see if it was a cause. Still cuts out, and now I need a new Knock sensor ( broke off at connector)
I am going to take the distributor out and try and see if there is wear on the intermediate shaft/oil pump gears, otherwise I will just keep wiggling LM wires
So any other suggestions would really be appreciated!

[jpcturbo]

You should try a stock cal or the MP stage 2 if you can. I know Rob is very good and this is a long shot but if either one of the cals still cuts out then you have pretty much eliminated the LM as a problem.

Also I remember if the TPS is installed wrong the engine will also cut out, but I think that was more like 3000rpm not 4600.

Jeff

[trannybuster]

Bad connection somewhere. Been there before. Throwing random dumb codes. It's one of those wires that you had to swap on the lm plug I bet. Check and double check them all. With the car running unbolt the lm from the car and wiggle wires till it dies or acts strange. Took me a week to figure out it was a loose wire.

Def check your wires, especially the map,although with all those codes you've probably got a few issues. Check your wiring as stated ^^..and friends cars you test that thing in, or send it to someone just to try, I doubt its the cal itself.

[black86glhs]

I have read through the whole thing and have not seen anything about checking the connections at the logic module. Not just the wires. If it has not been done, I recommend squeezing the terminals together slightly in the LM connectors. I had one cause a bunch of codes and would sometimes go to redline, other times cut out around 4k. Did what I suggested, no problems since.

Sent from my DROID X2 using Tapatalk

[boboli]

I took the distributor out and the intermediate shaft looks good. I compared it to a short block from a 91 tbi shadow w 82k and they seem to be very similar.

Rob mentioned the tps could be a problem. I tested the sweep of the tps. Voltage at the Lm starts @ .92 and sweeps steadily up/ without problems. tested the map. With the key on/car off, the map registered 1.5v. I then put some compressed air to it slowly and the voltage raises steadily.

The car has not displayed any of the problem codes since the ones I originally listed. This is the way the car has been since I got the new cal. I only get 12 and 55. The check engine light comes on when you disconnect the temp sensor, but once you cycle the key, the temp sensor code doesn't display.
I don't know anyone in town with the set up I have. I sold the mopar stg 2 cal I had. I can put the original T2 cal in the chip socket, but it didn't seem to like running with +40's and I have a 2 piece intake so I don't know how easy it would be to swap injectors

my Lm plugs may be the problem. Robs cals worked fine at first, but he was helping me taylor them to my car. I unplugged the Lm a couple times to swap chips, and somewhere around the 2nd chip, this problem appeared. My red plug goes into the pins very tight. You pretty much have to pry it away from them. The blue plug can just be pulled in one stroke. Don't know why they seem to attach with different force so I am going to pull every pin and check them. Maybe there is a bad connection in the blue connector.

[boboli]

i decided to really go through the Lm connectors. When i worked on the wiring harness a few years ago, i soldered several connections right at the Lm connector ( causing a stress point) and my added wires for the 4 wire AIS and some others were from the hardware store. I found TBI Lm connectors from an 87 and these had inserts that hold the lm pins in place. I decided to use these ( hoping this will help guarantee a connection at the lm) and replace my blue and red connector. I had to shave off the tabs that align the TBI LM sockets since they don't match up to the turbo ones. I was also able to use many of the tbi lm wires to replace the wires i suspected might be a problem, as well as I can now diagnose easier because the wires ( added AIS and others) actually match the stock lm wiring diagrams.
After a few hours, i am happier/confident with my Lm connections,and I still have cut out.
I have talked to Rob and he is helping me try to figure this out.
I am down to believing this is either a cal problem or an intermediate shaft.
I don't have proof for either, but I don't know what else would cause a fuel cut out at that rpm. It has to be the computer cutting fuel for some reason.

[bill2]

Try another LM, sounds like a bad LM...

Yeah but where is he going to find someone local with a t2 glhs module?, Oh wait I know! Pm me Matt!

[boboli]

Success!!!!!!!!!!!!
After talking to Rob, he told me that he never turned off the staging limiter in my cal. I decided to test to see if the lm was getting a signal from the speed sensor. It wasn't. I had tested the speed sensor off the car and it worked. When I unplugged the short jumper harness from the speed sensor, I saw that the retainer to hold the pins in place was gone and the pins were falling out the back. I had a spare, installed it, tested it at the LM, and all works great now!
Thanks to everyone who helped !!!

[BadAssPerformance]

Awesome, glad you figured it out!

[jeff1234]

Boy does this ever sound familiar. I am having almost the identical problems with my Charger and 2 different chips I got from Rob. I did have codes 13 and 15 so as soon as I can I am going to pull the speed sensor and see if I can find problems similar to yours. I don't believe it's Robs chips and he has been just great helping me out. I hope I find something this thing is driving me nuts. jeff1234

[boboli]

Mine was definitely the connector to the speed sensor. I was talking to Bill2 and he was having a similar problem with a cal I loaned him. He has a otc scanner, and it showed a speed sensor signal, so he was stumped. Later he realized that every now and then he would loose sensor signal. I think he replaced the speed sensor and that fixed the problem