Passing power with the 4L80E or lack of

[The FLU farm]

All components cause some power loss, but to say one transmission over another sucks more power is wrong. This "urban legion" came about from the racers using the 2 speed GM "Powerglide" in place of a TH400 or even a TH350. There used to be a chart that listed the parasitic drag of transmissions and transfer-cases and differentials we had in Tech school. The numbers where miniscule. So I stand by my statement.

I stand corrected. Always heard that the larger automatics soaked up more power, and with larger (and sometimes more) parts, it made sense to me.
Getting rotating mass up to speed versus keeping it in motion are obviously two different things.

 

[Kaiserjeeps]

I have always appreciated the knowledge base here. And yes that whole experience did teach me a lot. It also gave me confidence to dive into an automatic if the situation comes about. So in every bad situation, there is something positive to take away from it.

I ordered new injectors from Rock auto last night. It was 381.00 bucks. I did some reading beforehand and saw about 2007 they were 14 bucks. The highest price I saw were AC delco new units for 151.00 with a core charge. If they have a core, are they really new? Things sure have changed cost wise.
I hope throwing a little more money at this will help with my power issues. I will need to do firewood with a loaded M101 trailer in a month or so. It is regular driving with no load that seems to be so lacking. I will improve it as much as possible.

 

[Chaski]

New injectors are always nice. Have you read your transmission controller manual and double checked everything? Had someone else stomp on the accelerator pedal and make sure the arm on the injection pump has hit the stop? If the controller uses an add on throttle position sensor is it set up correctly? Have you experimented with the programming on the controller?
Plus you might want to get a tachometer to more accurately tune the shift points. Tinytach makes an inexpensive diesel tachometer.

 

[gimpyrobb]

How about a chassis lube? Is the driveline good and lubed up? Never hurts to make sure nothing is binding. Fluid levels in diffs good, etc?

 

[armytruck63]

Any brakes dragging?

 

[Kaiserjeeps]

I do have a TPS. I think the controller is working fine. In speaking with the manufacture about my truck, they programmed it for me before sending it based on my diesel app. All I have done is raise the lock up speed from 45 MPH to 55 MPH as it was hunting while driving on gravel to the highway. The change has worked well. If I give it some significant pedal it comes out of lock up and will downshift if I call for more than a standard maintain the speed thing. It also won't downshift to 3rd if my road speed is to high. I have been pretty happy with the unit so far. The only real issues I had was truck related. I lost power a couple times to the controller. That made the trans loose pressure and almost over reved the motor. It was a problem in the fuse block. Despite major close examination and cleaning, I never figured it out. I move the supply wire to the same power feed to the injection pump. Been flawless since. I also replaced all the fusible links with exact replacements.

I do have a nice tach. I did a write up on it. Crank based VDO. It has quit a couple times from the fuse box issue. But the tach works great. Looks good too.
All oils are good. The transfer case got all new gears and synthetic oil. The front diff goes milky fast and somehow it is collecting moisture I think. The rear diff is good. I have 42K original miles on it. It was an airforce truck so it probably has lots more use on the motor from sitting and running.

I will slip it into neutral while coasting to see if the brakes are hanging up. Good call as the road salt here is brutal on calipers and cars in general. I have been coating the undersides with Fluid film. That stuff is amazing and the Mil testing on it passed by miles. The navy uses it. Fluid Film has a web page that is interesting. I have never done the brakes and had planned on inspecting soon. I only buy premium top quality brake parts no matter what I am working on here. I will check the brakes when I can get to town out of the ice here. Or check for excess heat up here after a drive.

I want to do the compression test. I have a new tester that I have not opened yet. Do you do them hot? or cold? I need to find that in the manuals and go for it.
I also was going to shoot the exhaust manifold ports with a temp gun. I am pretty new to diesel's. If you can't tell by now...

I should post up some stuff on my 4L80E install. Once I got past the bad shop and fixed everything, it was fun to make the change. It sure made it drivable here. People haul butt here. But they don't tailgate which is just great.

 

[Chaski]

Did they send you a chart of the program?

 

[Kaiserjeeps]

No they did not. I believe they lowered the shift points based on my gear ratio, tire size and the 6.2. I don't have any complaints with the transmission at all. It is the motor and not making enough power at higher RPM's. I really doubt it is a transmission issue. I could be wrong I guess. I am hoping to at least find out compression numbers and see what happens with new injectors soon. Is has been super cold here and unfortunately there is a paint booth erected in the way in the shop, not to mention a completely disassembled jeep wagoneer all over the place. So I have to work outside. It was 5 above last night. I must be getting old as I am waiting for it to warm up just a little to do the work.

 

[Patattack]

6.2 were never meant to be tow monsters they were designed to be fuel savers. My 99 6.5 is slow as **** but she gets the job done a still makes money. You want more power put a Cummins in it like I did (way more powerful then the turd 6.2) or just drop a 350 or 454 in it. Your going to spend some money trying to get it to do what you want it to do. Just my 2 cents.

 

[NDT]

Here is my bone stock tired ex-AT&T 3500 turbo 6.5 4x4 with 4L80E at 22,000 GCWR. Roars up steep hills at 65 mph, flats at 70+. Power and fuel economy of this engine is beyond what I ever imagined.

 

[Kaiserjeeps]

I thought about a different truck. I am having a hard time parting with this one. It has grown on me. Plus like everything I seem to own, I end up throwing more money at it than it is worth. I paid too much for the truck and ended up fixing many things so far. My logic is it is low miles, plus the recent work with the trans and transfer case make it a keeper. I have researched the cummins thing to no end. Plus I met a guy who put one in his 85 Suburban. I did lots of conversation with him. If I kept the 4L80E the flex plate was 800 plus the adapter was about a grand. I searched for buses and stepvans on CL. Everybody wants a cummins here. Old tired ones claim top dollar. Plus from what I read, my truck would need a different brake booster from clearance issues. Not to mention a 2 inch lift. Maybe being a mil truck the lift would not be needed. But there was a ton of stuff to address being this vintage Chev. I would need a dodge truck for all the parts. More so if I switch transmissions again which makes more sense now. I added up all the costs and it came to about 6K. I mays well buy a dodge or chev truck and fix that one instead. Or get a gas motor. I am undecided so far. I wish I had realized all this before hand. Like my duece I used to have, same with the M715, I just had to have it. Wisdom takes a while sometimes.
Then there is the time issue. I have none extra. I am fixing cars up for others. Mine sit and wait. I definitely want to solve this one. I intend to recover a couple wagoneers this summer. I need to be able to trailer them. And JEGS just sent a flyer full of engines. I am trying not to look.
I am going to go read the manuals. I need to do that.
Thank you for the feedback. I do appreciate it.

 

[gimpyrobb]

Sounds like its time to do a compression test. That will give you an idea of the health of your motor. No need to go too far if its got a major issue.

 

[Kaiserjeeps]

Yes and I found it. Great manuals there.

COMPRESSION TEST — DIESEL ENGINESTo determine if the valves or rings are the cause of low compression, a test should be made to determine thecylinder compression pressure.When checking compression, the cranking speed must be at least 180 RPM and the engine fully warmed-up (EngineOil Hot). The lowest reading should not be less than 80% of the highest and no cylinder reading should be lessthan 2622 KPA (380 PSI)1. Remove air cleaner then install intake manifold cover J29664-1.2. Disconnect the wire from the fuel solenoid terminal of the injection pump.3. Disconnect wires from glow plugs then remove all glow plugs.4. Screw the compression gage J-26999-10 into the glow plug hole of the cylinder that is being checked.5. Crank engine.Allow six “ puffs” per cylinder.NORMAL — Compression builds up quickly and evenly to specified compression on each cylinder.LEAKING — Compression low on first stroke tends to build up on following strokes but does not reach normal

Now if it would just quit snowing

 

[Kaiserjeeps]

Well this is good news. I found one semi loose glow plug with carbon past the seat. The previous owner put in the better AC60's . I think that was the number..
Engine warm, 6 cranks each.

#1 420
#2 410
#3 410
#4 400
#5 400
#6 410
#7 410
#8 420

The injectors should be here in a couple days.

 

[Barrman]

Those are good number Al.

While you are waiting for the injectors. Start researching 6.2 IP timing. It is kind of a black magic process with the no longer made equipment. Without it, you are just guessing. I have 4 6.2 engines on the road just about daily in my family. Each one sounds different at idle, each one has different power levels and each one starts just a little different cold.

My first M1009 had a leaking throttle shaft seal soon after I got it. I was consistently getting 20-23 mpg running around town and down the highway at 60-63 mph. I replaced the ip and dropped to 16-18 mpg. I had the ip a line width to the drivers side of the timing mark. I started moving it around and then driving a tank of fuel. I got up over 20 mpg again but it was louder, blew some smoke and sometimes didn't start as fast as the rest. I moved it back just a bit and got better mpg, way more power, no smoke and super fast starts.

I moved it it just a touch after that to get better if possible. It wasn't and I haven't been able to find that sweet spot since. I actually have just been driving it as is because it still drives good. I think I figured out a way for me to figure out a starting point on timing since everything I have read says ip movement doesn't directly relate to timing changes. I just haven't had the time to play with it again.

What at I am suggesting is that once you do the injectors. Another low or no cost thing to try is the ip timing. Just research some first.

 

[Chaski]

Well, those are decent compression test numbers.

Gotta keep it in mind that you have about 100 horsepower at 1800 rpm, and a whopping 150 ish right around the rev limiter somewhere around 3600. If your controller isn't downshifting and letting you get to nearly redline when your foot is on the floor before it shifts you are missing out on precious horsepower.

 

[Kaiserjeeps]

Thank you Tim and Chaski,
I was pleased to see those numbers. It shifts out of lockout when I want to pass. Into 4th. It just feels washed out. I will make a note of what RPM I am at next time I drive it and nail it. And I did a little reading on IP timing and ended up in the rebuild stuff that made my head spin. I will try a little adjustment as you recommend Barrman later after checking the TPS, throttle cable travel, etc
I dug out the transmission file this morning. I ran the DVD and it has a lot of great information. A little more comprehensive then the paper guides. But I don't feel the need to really change anything regarding shift points, shift firmness etc. I do like this brand of controller. (US Shift Quick 1) I am glad to be finally doing something on this issue. I am hoping for an improvement even if it is a small one.

I also want to reweigh my truck. If I remember correctly it was 7200. Is this overweight compared to most?
I hate driving it this time of year from the massive amounts of road salt. Can't avoid it though.

 

[gimpyrobb]

Jack the truck up and put it on blocks(a lift is even better).
Get an "undercoating" gun from horrible freight.
Spray the underside liberally with used motor oil.

It keeps most stuff lubed and really cuts down on the effect of road salts!

Its even easier if you have a 5ton wrecker. Maybe its time to shop for another vehicle...

just sayin.

 

[ken]

What elevation is this pass at? What grade? it might be starving for air. If a turbo isn't a option then maybe a early 90's single plane intake, air cleaner and a ram air snorkel will help.

 

[Kaiserjeeps]

Jack the truck up and put it on blocks(a lift is even better).
Get an "undercoating" gun from horrible freight.
Spray the underside liberally with used motor oil.

It keeps most stuff lubed and really cuts down on the effect of road salts!

Its even easier if you have a 5ton wrecker. Maybe its time to shop for another vehicle...

just sayin.

I have fluid film all over the place. I like that stuff a lot. That is what it is made for. It creeps. I have some sheet metal to fix now. But that us what I do for work now.
I think in the long run, given the low miles, a V-8 gasser is what I would like to do. I see some pretty neat motors in JEGS, Summit etc. I will always look at Craigs list, but that is a gamble with people. I also need to make sure I can swing it financially. My dreams often outweigh my bank account.

I have another thing that might be the culprit. The previous owner bypassed the stock fuel pump. There is an electric pump down on the fender skirt. This just occurred to me while compression testing. I had better return everything to original. It was handy to disconnect while trouble shooting. But leaving it off starves the IP after a call for power and it shows. I will fix that. The new injectors showed up. So did an absolute pile of snow. I am off to plow, then I can have my day back.

Ken, The mountain pass was 4th of July pass in North Central Idaho near the silver valley mining region. It is steep, long and it was hot outside. I made the summit doing 10MPH and fast approaching 230 degrees. Another 300 feet and I would have had to pull over and cool things down. I crested the summit pretty much projectile sweating at that point, and it cooled and picked up speed. I don't know that altitude but can look it up later. The towing load was a 4200 LB Jeep CJ on a 1000 lb trailer. I do understand I was asking a lot from the 6.2. I did not understand this when I bought the truck. I like the truck. Changing everything may not be the best thing to do to it. But I need to tow once in a while. I'll make sure the 6.2 is doing it's best. But I believe I have found it's limitations.
I had better get to plowing. There is supposed to be more coming.