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4L80E No Power - Recent Engine Swap

Ok. If the trans light is on when it is not connected and the tachometer does not work with it disconnected...
Then connected the trans warning light goes out and tachometer works- that is probably not the problem. I can’t understand how the tachometer would work if it didn’t have the reluctor wheel in place. I am assuming the tach is showing proper rpm (at least apparently)

@THEFERMANATOR becomes the go to guy again.
 
Will L. said:
Ok. If the trans light is on when it is not connected and the tachometer does not work with it disconnected...
Then connected the trans warning light goes out and tachometer works- that is probably not the problem. I can’t understand how the tachometer would work if it didn’t have the reluctor wheel in place. I am assuming the tach is showing proper rpm (at least apparently)

@THEFERMANATOR becomes the go to guy again.
Click to expand...

Well...crap.

However, the DS4 has a camshaft sensor in it, right? I came upon a blurb at one point that mentioned it in passing. If the DS4 has a sensor, and I'm still DB2, I'm still down a sensor. All you have on your truck is the CPS? Just want to rule it out before I move on to hunting for something else.

Now, my fancy homemade tach to CPS harness is not shielded, so the tachometer hops around at the moment when I step on the brake. Could that still cause the transmission issue or that's a small fry, just shield it and move on to wherever the real problem is.
 
Okay, where does the alternator come into to play at signaling the tachometer ? I thought all the 6.5s pulled tach signal from the alternator.
To verify if You have a CS reluctor wheel installed, can the CPS be removed and the spacer/harmonic balancer be felt through the hole ?
Then, the cam shaft rotates at 1/2 engine speed. Is it possible to grind off 1/2 of the points on the reluctor wheel to het the results the cam shaft would be at ?
 
MrMarty51 said:
Okay, where does the alternator come into to play at signaling the tachometer ? I thought all the 6.5s pulled tach signal from the alternator.
To verify if You have a CS reluctor wheel installed, can the CPS be removed and the spacer/harmonic balancer be felt through the hole ?
Then, the cam shaft rotates at 1/2 engine speed. Is it possible to grind off 1/2 of the points on the reluctor wheel to het the results the cam shaft would be at ?
Click to expand...
That should be possible, good thinking on whether or not the reluctor is in place.
 
Negative on the alternator for tach or anything on hummers/ hmmwv. It all came off the ESS for non turbo - which all had db2 ip. The civilian hummer with turbo all were ds4 and used CPS for tach info.

@cander27 There is not a real camshaft sensor. Obd2 compliance made that a required indication- but on the 6.5 it is a part inside the ds4 ip. But your TCM DOES NOT CARE. Your TCM will not take any info from that. Your transmission cares about ESS, TPS, VSSB, TISS, TOSS. Nothing else tells it squat I am aware of. One thing maybe it gets it trans pressure - but not sure.

The fact that you Tachometer jumps around IS something to WORRY about. If that signal is messed up- the tcm doesn’t get a clear picture of what is happening. If your engine is smooth at 2200 rpm but the gauge is jumping from 1500-2500 rpm- that is what the TCM thinks is really happening. That is something to solve.
 
Will L. said:
Negative on the alternator for tach or anything on hummers/ hmmwv. It all came off the ESS for non turbo - which all had db2 ip. The civilian hummer with turbo all were ds4 and used CPS for tach info.

@cander27
The fact that you Tachometer jumps around IS something to WORRY about. If that signal is messed up- the tcm doesn’t get a clear picture of what is happening. If your engine is smooth at 2200 rpm but the gauge is jumping from 1500-2500 rpm- that is what the TCM thinks is really happening. That is something to solve.
Click to expand...

And if there is just a spacer bestween the HB and the crankshaft timing sprocket, that could possibly cause the tach to jump around.
I’m just making a guess at that. Irregularities on the spacer might give a bad signal to the tach, could be created also if the CPS is picking up off of the sprocket too, with nothing else for it to fix its magnetism too. 🤷‍♂️
 
Will L. said:
Negative on the alternator for tach or anything on hummers/ hmmwv. It all came off the ESS for non turbo - which all had db2 ip. The civilian hummer with turbo all were ds4 and used CPS for tach info.

@cander27 There is not a real camshaft sensor. Obd2 compliance made that a required indication- but on the 6.5 it is a part inside the ds4 ip. But your TCM DOES NOT CARE. Your TCM will not take any info from that. Your transmission cares about ESS, TPS, VSSB, TISS, TOSS. Nothing else tells it squat I am aware of. One thing maybe it gets it trans pressure - but not sure.

The fact that you Tachometer jumps around IS something to WORRY about. If that signal is messed up- the tcm doesn’t get a clear picture of what is happening. If your engine is smooth at 2200 rpm but the gauge is jumping from 1500-2500 rpm- that is what the TCM thinks is really happening. That is something to solve.
Click to expand...

I believe it's jumping around as the wiring isn't shielded, I could be wrong. A side thought possible brake switch issue? I know they can cause mayhem when they start failing, but I've never dealt with it so I'm not entirely familiar with symptoms.

Help me to understand, because I think you have a major piece of the puzzle that will solve my problem. You did the mechanical turbo mod and have a working truck. The only difference (correct me if I'm wrong), is that I have a new 6.5 GEP and you have a 6.5 NA or Optimizer? What am I, and it appears every other mechanic and vendor, missing with my truck? Either something else was forgotten in the build (like the CRANKSHAFT SENSOR NOT BEING PLUGGED IN...I'm still blown away by that), like a piece is missing, or something was disturbed during the build.

That leads me to think: The transmission is a symptom of the problem. So what can cause the transmission to consistently screw up IF it's not transmission related? When I'm sitting in park it's making clicking sounds randomly on it's own, TC lockup?

I've been going over grounds like crazy, and can't find any ground issues. I have noticed from time to time an oddity with the glowplug wait light not always coming on when the glowplug controller is audibly heard clicking on. Then it does light "Wait" with the controller clicking. Then it doesn't do anything at times (i.e.: starting under compression). I'm thinking we are looking at something electrical (sensor, ground, wiring issue, frayed), but I have no idea where to look. I've religiously checked the fuses multiple times over months.

I still think there is 1 thing that is waiting to be found but I don't know where to look.

I still need to jack the truck up and see if something has seized, that's the only non-electric thing off the top of my head I can think of.
 
MrMarty51 said:
And if there is just a spacer bestween the HB and the crankshaft timing sprocket, that could possibly cause the tach to jump around.
I’m just making a guess at that. Irregularities on the spacer might give a bad signal to the tach, could be created also if the CPS is picking up off of the sprocket too, with nothing else for it to fix its magnetism too. 🤷‍♂️
Click to expand...

NO. Completely not.
 
cander27 said:
I believe it's jumping around as the wiring isn't shielded, I could be wrong. A side thought possible brake switch issue? I know they can cause mayhem when they start failing, but I've never dealt with it so I'm not entirely familiar with symptoms.

Help me to understand, because I think you have a major piece of the puzzle that will solve my problem. You did the mechanical turbo mod and have a working truck. The only difference (correct me if I'm wrong), is that I have a new 6.5 GEP and you have a 6.5 NA or Optimizer? What am I, and it appears every other mechanic and vendor, missing with my truck? Either something else was forgotten in the build (like the CRANKSHAFT SENSOR NOT BEING PLUGGED IN...I'm still blown away by that), like a piece is missing, or something was disturbed during the build.

That leads me to think: The transmission is a symptom of the problem. So what can cause the transmission to consistently screw up IF it's not transmission related? When I'm sitting in park it's making clicking sounds randomly on it's own, TC lockup?

I've been going over grounds like crazy, and can't find any ground issues. I have noticed from time to time an oddity with the glowplug wait light not always coming on when the glowplug controller is audibly heard clicking on. Then it does light "Wait" with the controller clicking. Then it doesn't do anything at times (i.e.: starting under compression). I'm thinking we are looking at something electrical (sensor, ground, wiring issue, frayed), but I have no idea where to look. I've religiously checked the fuses multiple times over months.

I still think there is 1 thing that is waiting to be found but I don't know where to look.

I still need to jack the truck up and see if something has seized, that's the only non-electric thing off the top of my head I can think of.
Click to expand...

PM to you of my phone number. But today is wedding anniversary so conversion might be choppy today. Tomorrow is open.

GM or GEP optimizer makes no difference on this. Mine is optimizer but with ds4 capable timing gears.

Wait to start and brake have no effect on tachometer. Tachometer is getting bad signal then so it trans controller. I see this as must fix first.


Nope. there is no shielding on any of the cps or ess.
It is just 2 wires, 14awg. You could make your extension cable out of shielded wire if you wanted to, rembering to only ground one end of any shielded wire. It would not hurt anything. But I highly doubt it will fix anything.

I don’t know the signal to look for - (DOES ANYONE KNOW HOW TO READ A CPS AN OSCILLOSCOPE?) nor know the circuitry. My hummer manual is a $20 chineseium knock off one someone on ebay printed out and sold for $25 way back in 2004. And unfortunately the wiring schematic section is basically blurred junk. I never have bought the actual manual because of cost (I thought it was a good deal on a used one back then and my first ebay purchase- lesson learned).
I think you really need one here because there is too many changes year to year and between pickups vs hummers.

I dont know 100% the military 2 wire CPS and mine are functioning exactly the same.
My understanding is all 2 wire sensors work identical.

@THEFERMANATOR is the one that explained the difference of 2 wire and 3 wire pickups to me. (I am sure I had it in class but it never stuck in my brain) Maybe Ferm can say how to test your 2 wire cps? Or if you should just replace it? I know it is magnetic and you could have metal shavings stuck to it causing disruption like when an a d sensor gets some on it (but that means scary stuff metal shavings in the engine). Free is removing it and wiling it clean to be sure - but I seriously doubt anything will be on it other than a little oil.

How far are you from Florida? Maybe Ferm can take on one side job? You have to do the physical work while he tells you and he watches computer screens. He isn’t turning wrenches since messed up his back. But the knowledge bowl is still full. Would be better and cheaper than ModMafia ride. There is that one amazing dude in California you can ask about on the other forum. He has the 95 computer adaptation stuff a

I am sure you are best off with someone who is an expert on the obd1 4l80e equipped trucks. You and I are in the no-mans land with the 95. I figure worse case scenario I might abandon factory trans module and go with an aftermarket stand alone if it ever comes to that.

Yours is more complicated because you had transmission issue and someone messed with it and maybe they goofed something up.

Did you add the turbo? Do you still have the ESS where you could remove turbo temporarily for test drive and install the ESS? That could eliminate the cps questions.

Do some rubber hose plumbing for intake and point up pipes downward, put flex pipe on each one pointed down to ground with bailing wire and seal temporary with the aluminum foil hvac tape. Use the “8” oring turbo oil seal and. A piece of angle iron metal using turbo mount bolt holes to plug oil feed and keep out dirt from return.

A lot of work just to verify but you really need to eliminate possibilities.

A REALLY expensive shot would be that 6 speed set up that Phoenix Hummer is doing. The trans is not as strong as a 4l80e, so rebuilding that should be estimated to be done every 100,000 miles. But MAN those gear ratios are tempting!
He has not done a db2 hummer yet so maybe a reduction in price for being Guinea pig? He said the GM engineers are working with him on this- just verify it is really a currently employed GM engineer. Then get ALL the specs FROM THAT ENGINEER of the trans and whole system so you can have it repaired/ replaced in the future if Phoenix Hummer goes out of business.
 
Will L. said:
PM to you of my phone number. But today is wedding anniversary so conversion might be choppy today. Tomorrow is open.

GM or GEP optimizer makes no difference on this. Mine is optimizer but with ds4 capable timing gears.

Wait to start and brake have no effect on tachometer. Tachometer is getting bad signal then so it trans controller. I see this as must fix first.


Nope. there is no shielding on any of the cps or ess.
It is just 2 wires, 14awg. You could make your extension cable out of shielded wire if you wanted to, rembering to only ground one end of any shielded wire. It would not hurt anything. But I highly doubt it will fix anything.

I don’t know the signal to look for - (DOES ANYONE KNOW HOW TO READ A CPS AN OSCILLOSCOPE?) nor know the circuitry. My hummer manual is a $20 chineseium knock off one someone on ebay printed out and sold for $25 way back in 2004. And unfortunately the wiring schematic section is basically blurred junk. I never have bought the actual manual because of cost (I thought it was a good deal on a used one back then and my first ebay purchase- lesson learned).
I think you really need one here because there is too many changes year to year and between pickups vs hummers.

I dont know 100% the military 2 wire CPS and mine are functioning exactly the same.
My understanding is all 2 wire sensors work identical.

@THEFERMANATOR is the one that explained the difference of 2 wire and 3 wire pickups to me. (I am sure I had it in class but it never stuck in my brain) Maybe Ferm can say how to test your 2 wire cps? Or if you should just replace it? I know it is magnetic and you could have metal shavings stuck to it causing disruption like when an a d sensor gets some on it (but that means scary stuff metal shavings in the engine). Free is removing it and wiling it clean to be sure - but I seriously doubt anything will be on it other than a little oil.

How far are you from Florida? Maybe Ferm can take on one side job? You have to do the physical work while he tells you and he watches computer screens. He isn’t turning wrenches since messed up his back. But the knowledge bowl is still full. Would be better and cheaper than ModMafia ride. There is that one amazing dude in California you can ask about on the other forum. He has the 95 computer adaptation stuff a

I am sure you are best off with someone who is an expert on the obd1 4l80e equipped trucks. You and I are in the no-mans land with the 95. I figure worse case scenario I might abandon factory trans module and go with an aftermarket stand alone if it ever comes to that.

Yours is more complicated because you had transmission issue and someone messed with it and maybe they goofed something up.

Did you add the turbo? Do you still have the ESS where you could remove turbo temporarily for test drive and install the ESS? That could eliminate the cps questions.

Do some rubber hose plumbing for intake and point up pipes downward, put flex pipe on each one pointed down to ground with bailing wire and seal temporary with the aluminum foil hvac tape. Use the “8” oring turbo oil seal and. A piece of angle iron metal using turbo mount bolt holes to plug oil feed and keep out dirt from return.

A lot of work just to verify but you really need to eliminate possibilities.

A REALLY expensive shot would be that 6 speed set up that Phoenix Hummer is doing. The trans is not as strong as a 4l80e, so rebuilding that should be estimated to be done every 100,000 miles. But MAN those gear ratios are tempting!
He has not done a db2 hummer yet so maybe a reduction in price for being Guinea pig? He said the GM engineers are working with him on this- just verify it is really a currently employed GM engineer. Then get ALL the specs FROM THAT ENGINEER of the trans and whole system so you can have it repaired/ replaced in the future if Phoenix Hummer goes out of business.
Click to expand...

Happy Anniversary dude! Got it and thank you!

I'm in Tallahassee/Monticello, FL.

It was a swap after I cracked my old stock 6.5 NA. So brand new 6.5 GEP, Super 77 turbo. Most of the hoses are now new. The transmission is practically as I had them do a billet build and they wound up changing out the housing. Solenoids are new on the transmission as is the internal harness and filter. No longer have the old ESS as the shop where my old engine ESS are at is shutting down. It's possible with the new engine that metal shavings did wander. I've since changed out the fancy new engine oil, so whatever shavings were in there are likely gone. I could replace the crankshaft sensor and see what happens, but I've put more than $20k into the truck now and am very hesitant to throw anything else at it until a problem is truly identified. I will almost have a new truck once the problem is found...but after 11 months of not having it driveable...I don't really care, I just want it to work!

Just on the outskirts of town is Donaldson Diesel, they are apparently very well known. But again, I'm hesitant to throw money at it unless I can find or majorly narrow down where the problem is. That's why I'm back, I'm desperate for ideas and knowledge.

I'll PM you.
 
Husker6.5 said:
@THEFERMANATOR lives over in Zephyrhills, FL. Not exactly next door, but at least it's not Lost Wages, NV!
Click to expand...
I see you understand the proper spelling!
Until the 08 crash- there was always tons of jobs available doing all kinds of different things. Right to work state so you could choose union or not regardless of what you’re doing (almost). This place is like the good job adage of golden handcuffs- And once you are 1 mile from the strip most everything is like any normal city except the video poker machines in every 7-11 and even grocery stores.

The whole valley is basically a bowl surrounded by mountains 25 miles in diameter. It’s gonna make an amazing fire pit one day once God has had his fill. Instead of sodom and gomorrah having the sulfur and fire from the heavens, maybe it will be from the ground up? Burn high enough flames they could be seen from farther away than the luxor light would be fitting. Vegas was a young man’s trappings to me with the ease of income, for most it is tons of entertainment. All golden cuffs for sure that I should have left years ago but now my kids are comfortable and happy here like I was when I was young and dumb. Unfortunately now I stay for they want to be here and because I am old and dumber.
 
The crankshaft sensor not being plugged in definitely hid a lot of issues. Now that it has been plugged in the truck runs better, but randomly stutters every now and then, BUT I think that is related to something else. I believe whatever this is, is entirely electrical. So the hunt for the great gremlin has begun.

Update:

- All grounds are good and tight, no corrosion.
- With the truck running I ran up and down the main harness with my wife watching the tachometer (as it's jumping around like crazy), moving any part of the harness didn't level it out or cause higher jumping.
- Playing around in the doghouse wiring, no changes.
- Pulled the fuse panels off to check the wiring on the back of the fuse panels, nothing corroded, burned, melted or loose.
- Every fuse checked and re-checked
- Changed out the alternator on a theory...nope, now I have a new alternator (yes this is a theme, just about everything has been replaced...tired of it)
- Checked each of the transmission harness's wires to see if any were loose, all tight and secure.
- Checked each pin going into the computer, all secure.

Then while trying to come up with new tests and combinations I found a new pieces of the puzzle that did something.

Test 1
With the truck running (glowplug relay did not kick on, started under compression) and the tachometer jumping around I unplugged the transmission harness. Tachometer stops hoping around. Still couldn't get into reverse. I plug the harness back in and the tachometer continues to remain normal. Still can't get into reverse, D has very little power, OD is not happy.

Test 2
Unplug transmission harness and start truck (note, glowplug relay kicks on this time and door chimes once, it actually startled me). Starts normal, tachometer normal, still doesn't want to shift but always shifts to D with little power. Plug in transmission harness, tachometer stays the same. Turn off truck, turn on truck, tachometer jumping around like its being electrocuted again.


The above was consistent on repeated attempts. If the truck was started and tachometer jumping, unplugging the harness would kill the jumping. Plugging it back in while running would keep it level. Starting with it unplugged kept it from jumping around.

Tempted to put the old glowplug relay back on and see what happens.


Would this be more related to the computer seeing as how I'm unplugging the brain from the transmission and the voltage oddities disappear? Or, does this sound like the harness? Could a glowplug relay somehow affect the system? Trying to find out if I can get a technician to come by the house with a Tech2, finally found a shop that has one nearby.

That's the news for now.
 
Update

Had to shift to building our house which is finally done, woo, so back to the truck now.

Transmission shop rebuilt the transmission with billet parts and on each test drive at a stop the truck would shut down. On restart the truck would drive normal. They had to rebuild 3 more times. The final time they put in a new trans housing. Gave it to me and said drive it for a week and see if they fixed it…it drove for a day and I towed it home. Don’t think it’s the best shop around as they had majorly messed up my shift points and over filled the transmission by a bit, had them fix it before I took it on that last drive but it made me wonder about the quality of their work. The old trans was a Monster (only found that out from this shop), I would think after we did the engine swap we may have “disturbed the Monster”.

Towing it home I put in the EZ-TCU from TCI and it worked for a day. Had all gears, saw the TC locking and unlocking. Next day, back to no reverse, 3rd, 4th (OD).

Again, I went hunting for electrical issues, pulled out a bunch of wiring the previous owners had put in that I never used(heated seats, stereo). That didn’t do anything other than clean it up a bit. Did find some shorts and damaged wires and fixed them, that didn’t do it.

Digging into forums I found a few things that could cause no shifts, GM ignition switch failure and alternator, changed those out to no avail. It was clearly over my head so back to the trans shop.

They call me and say they are done working on the truck, lost too much money on it, please pick it up.

I go to pick it up and find the truck is dead. After working with them to jump it, no small feat, I take it home. The batteries could not be charged and had an open cell problem. New batteries.

I come to find they had accidentally ripped the 12v power wire to the Dokota Digital (takes analog RPM and speed sensor and changes it to digital for EZ-TCU) and shorted the truck. I’m clearly done with them, and they are supposed to be the best shop in town.

I change out all of the solenoids and look over everything as much as I could, notice there is some fluid on the trans pins. Debating if that’s part of the problem. Changing the solenoids did zero to change no reverse, 3rd and OD.

One of the metal workers on my house turns out to be a custom car guy, takes old cars, chops them up, makes them run. He and his buddy think outside the box and I decided to drop it off with them after telling them about the truck. They noticed I off handed mentioned no boost pressure from the turbo gauge, said they would start there.

On the way to their shop while playing with gears (because I’ve always been stuck in 1st and 2nd) I see the TCU switch to 3rd, followed by the truck making the switch. Dang, here I thought I’ve been stuck in limp mode this whole time. Felt great to have a few minutes of driving at 45mph. It managed to get into 3rd twice. This makes me think it has to be hydraulic.

It would hesitate and be a delayed shift getting into 3rd. The rpm had to be fairly high in second over 3k, I think going about 25+ mph. The thing that stuck out was how the TCU would switch, I would see the computer controller change to “L3” and then have a 1 or 2 second delay to the transmission making the shift. Driving felt normal in 3rd, it downshifted like a pro at the two stops I had. Of course, upon pulling up to the shop I still didn’t have reverse. But something new is definitely helpful.

Summary:
  • Not in limp mode, shifted to 3rd
  • Delayed shift to 3rd
  • Downshifted fine
  • Still no reverse, 4th or OD
  • No boost pressure


Questions:

  • Does this sound like a trans hydraulic issue instead of trans electrical?
  • Is no boost pressure related in any way? (Only becoming familiar with turbos since we put a turbo on the truck)
  • Instead of throwing more parts at the trans should I write it off and contact Jake’s Transmissions?
  • Should I try to tell the TCU to increase or decrease pressure and see if there is a change?
Thank y’all for helping me with this.
 
I'm no tranny expert of any mater but I would vote on getting a manual pressure gauge on the tranny to see what pressures it's actually producing. and how it acts when the TCU commands a gear shift then go from there. knowing what the tranny is doing compared to what the TCU says can help diagnose if it's a tranny or electric issue.

as for no boost pressure. I'm sure you have a mechanical wastegate setup and not the triditional vacuum lines and solenoid controlling it. make sure the turbo is freely spinning with the engine off and the air tube removed spin it with you fingers making sure the impeller isn't touching the housing or has a rough spot in the bearing / bushings. if all checks good look for an intake manifold leak. last resort would be looking at the internal wastegate flapper and see if it hasn't fell apart or froze open. that usually doesn't happen but is possible.
 
The boost gauge, is that an electronic boost gauge or is that a mechanical boost gauge ?
If mechanical, the electronics would have nothing to do with how the gauge functions and then You would be looking for a kinked or busted tube between the intake manifold and the gauge.
If the gauge is electrical, then be checking for power to the gauge and I would guess an ohms reading between the gauge and the sender unit and also for a good gauge to ground connection.
If it is electronical and the systems dont check out or are too difficult to check out, then, scrap that electronical unit and install a manual gauge. Just my o2 worth.
 
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