Newbie with ECU question

robot808

robot808

Well-known member
Aug 30, 2009
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Elmhurst,IL
Hello all. First of all, thanks for having me.
I just picked up a 1996 Disco with 142K miles (rescue mission). It starts with high idle then the idle is all over the place. When running it, stutters and lurches at all speeds. It will stall at stop signs until it is warmed up. I have tried several OBD readers and none can get a read from the port. I have checked fuses and connections which all seem fine.
The PO said he had taken it in and the mechanic said he needed a new ECU (sounds about right).
My question is, is the ECU plug and play or does it need to be setup with a Testbook?
I do realize that other things may cause similar behavior, but since I can't get an OBD reading, I think it is a logical place to start.
Thanks for any help
 
Jaime

Jaime

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Apr 29, 2004
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NJ
welcome!

I bet its the stepper motor / Idle Air Control.

do a search on the 2 terms above and you'll find a lot of helpful posts and tech info

As far as OBD, I use the one from http://obd-2.com/ connected to an old laptop but I'm sure there are others out there, just check that they support the Land Rover codes
 
robot808

robot808

Well-known member
Aug 30, 2009
110
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Elmhurst,IL
Thanks Jaime,
I have a Scangauge, plus went to several parts stores that couldn't get any reading. It seems to that since the OBD port isn't working AND the running is so erratic that the ECU is a good place to start.
If I can just get my codes read I would be happy with the new ECU. I am wondering if I can just put it in myself or if I need a tech with a testbook for the truck to recognize the new computer.
Thanks again,
Bob
 
p m

p m

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Apr 19, 2004
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flyfisher11 said:
Yes
Click to expand...
No.
With a 96 D1, you can plug in nearly any GEMS ECU, and it'll work.
The later-year-96 and on to 99 GEMS D1s had Advanced Evap setup - so using later ECUs may trigger the CEL eventually with codes around P0441, P0446, and P0451. May have to either retrofit Advanced Evap setup or fool the fuel tank pressure sensor.

PT - tell me it ain't so.
 
flyfisher11

flyfisher11

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May 25, 2005
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Wolf Laurel NC
p m said:
No.
With a 96 D1, you can plug in nearly any GEMS ECU, and it'll work.
The later-year-96 and on to 99 GEMS D1s had Advanced Evap setup - so using later ECUs may trigger the CEL eventually with codes around P0441, P0446, and P0451. May have to either retrofit Advanced Evap setup or fool the fuel tank pressure sensor.

PT - tell me it ain't so.
Click to expand...

It ain't so Peter, it ain't so! No seriously do we know where his '96 fits in. Are you suggesting that he try it and then see what happens? I guess he could but I'd be prepared to hook it up to the T-4 then if you don't need too then all the better.

Cheers,

Mike
 
p m

p m

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flyfisher11 said:
It ain't so Peter, it ain't so! No seriously do we know where his '96 fits in. Are you suggesting that he try it and then see what happens? I guess he could but I'd be prepared to hook it up to the T-4 then if you don't need too then all the better.
Click to expand...
Mike, here I only know what I've found for myself.
After the stealer told me in 2002 that my ECU was toast (despite obvious alarm problems), I got a 98 GEMS ECU from a breaker. I've replaced my (early 96) ECU with the 98, found that the problem was indeed elsewhere, but left the 98 ECU. A few years (!) later CEL started popping up, more as a reminder of impending smog check. This is when I figured out the differences (around 2005). Put back my 96 ECU, and haven't had any issues at all.
Didn't have to reprogram anything.
 
flyfisher11

flyfisher11

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May 25, 2005
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p m said:
Mike, here I only know what I've found for myself.
After the stealer told me in 2002 that my ECU was toast (despite obvious alarm problems), I got a 98 GEMS ECU from a breaker. I've replaced my (early 96) ECU with the 98, found that the problem was indeed elsewhere, but left the 98 ECU. A few years (!) later CEL started popping up, more as a reminder of impending smog check. This is when I figured out the differences (around 2005). Put back my 96 ECU, and haven't had any issues at all.
Didn't have to reprogram anything.
Click to expand...

It's all voodoo. I swear it would be nice to be able to know exactly when the changes were made however subtle. That is very interesting. Good thing you hung on to the old ECU.
 
p m

p m

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I can't tell you to go ahead and potentially fry an ECU.
But, personally, I wouldn't have a problem - I didn't have a problem - unhooking one and hooking another.
 
DiscoJen

DiscoJen

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Aug 27, 2004
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I had an engine surging problem that was addressed in a TSB on my 97 GEMs. Instead of spending the $100 for the PROM chip, I got an ECU from a junkyard from a 98 with a vin that was not affected by the TSB. Plugged it in and it accepted it almost immediately. Idled crazy for a few minutes like the devil had possessed it, then it simmered down all on it's own. No more surging.

Disclaimer: try this at your own risk, I cannot guarantee that it will work for you.

Oh yeah, when my OBD wouldn't read it ended up being a fuse. I had checked and checked and never found a bad fuse. Then I found it by pure accident, replaced it and OBD reads just fine. Double check your fuses again, you may have overlooked something.
 
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