1618625 bjdr

[HalfDoor]

Hello all!

I ordered my programmer and it should be here soon so I'm TRYING to read what I can and get things together to get up and running as soon as it gets here.
My intention is really simple. I have a 2000 Wrangler TJ that I converted to a V8. The engine is a 94' GMC 350/4L80E/NP241 combo. The engine runs really good except it seems to run a little rich on cold start, but I've heard that's normal for TBI. Anyway, my real problem is the ECM cuts out the fuel at around 50MPH. I'm assumimg it has to do with the speed limiter or something. I get to 4th gear and around 2300rpm when it cuts out. The engine is out of a 2500 truck that I believe had 3:73 gears. It now has 4:10 gears.

I've looked for files I will need, but all the files are 4L60E. I'm completely new to this and have a lot to lean. I know this.. But, can someone point me in the right direction as to what files or a "how-to" for what i need. The simpler the better. At the moment I'm more interested in getting this thing on the road and I can play with the tuning later...Yes, that means more reading and more questions!

Thanks again!

HD

[jim_in_dorris]

That's actually a $0E bin, not a $0D bin, so that's where you need to look. I don't know much about $0E code, but someone will be along shortly that will know. Do you have VSS installed? how about the wiring for the 4L80E?

[HalfDoor]

That's actually a $0E bin, not a $0D bin, so that's where you need to look. I don't know much about $0E code, but someone will be along shortly that will know. Do you have VSS installed? how about the wiring for the 4L80E?

Thanks got the quick response.

I have the VSS signal coming from the tcase. The wiring is aftermarket that makes the engine completely stand alone. The only thing, and I hope it doesn't matter, the ECM is out of a 2wd and the Wrangler is now 4wd (4WD 4L80E). I was told the tcase and 2wd 4L80E gives off a 40 pulse signal so it shouldn't matter. All my gauges are aftermarket by Speedhut.
Do you think its possible the computer isn't receiving a signal? The transmission is shifting ok. Not sure if the trans reads off the RPM or MPH??

Thanks!

HD

[Six_Shooter]

With the steeper gears, it possible that the PCM is reading a higher speed than what you are actually running at.

The easy way to adjust for this is modify the jumpers in the DRAC module, to compensate for the steeper gear, you can also account for tire height change as well.

[EagleMark]

But it's a conversion and he has an aftermarket wiring harness so most likely no DRAC/VSSB. No speedo or ? to buffer to and it's wired straight to PCM...

So the bin would need to have paremeter change "Output Speed Not from DRAC" Checked! It is always un-checked...

Then to fix the VSS because of gear and I'm sure not stock size tires, VSS paremeter change:
Title: RPM/VSS Ratio
Location: 5D19, 5D1A
Usage: 4L80-E VSS Parameters
8 x numeral gear ratio x 12 x 5280
Tips: Value = ------------------------------------------------ x 65536
512 x 60 x tire radius in inches x 2 x pi
Conversion: Ratio = 0.000977 * X

There may be some more 4L80E VSS paremeters that need adjustment but I'm not sure? Would have to record data and see what MPH is to actual... then stock RPM and MPH limiters would not be a problem and transmission would be shifting at correct speeds.

Where's Greg? He runs a 4L80E conversion in a Camaro.

[Six_Shooter]

But it's a conversion and he has an aftermarket wiring harness so most likely no DRAC/VSSB. No speedo or ? to buffer to and it's wired straight to PCM...

He's running a 4L80E, he has to have a DRAC/VSSB for it to function correctly. The "Output not from DRAC" is for not E transmissions.

[HalfDoor]

Thanks for the quick responses!

I did adjust the DRAC according to the calculations I read on the internet. I thought that may be the problem as well, but wasn't sure. Maybe, and I say say that with a clear conscience, MAYBE, I did the calculations wrong or missed a step. If someone would like to give it a go... ;-)

The only info I had to input was
tire size: Goodyear 35/12.50/15 Kevlar MTA
and gear ratio: 4:10

The results: 0.764548
or: 1011000

HD

[Six_Shooter]

Best thing to do right now would be to datalog and see what speed the PCM is seeing, it may be something other than a speed limiter or a combination of parameters causing it.

[HalfDoor]

Best thing to do right now would be to datalog and see what speed the PCM is seeing, it may be something other than a speed limiter or a combination of parameters causing it.

Ok, cool. I'll wait till I get the harware. Probably gonna be slow shipping because of the Holidays.

Thanks again to all who responded!

HD

[gregs78cam]

You do have the 4Lo input wired correctly? Is the fuel cut out at 50MPH on your speedo, or in the TunerPro dash? If that is actual 50mph then check to see what speed the PCM is seeing. I am wondering if the PCM thinks you are in 4Lo when your not.