computer tuning

greywolf · Posted: Sun Jun 03, 2007 9:59 pm Post subject: computer tuning

So you've heard me talk about the LT1 that went into my El Camino. Been chasing a fuel cut off problem for months, and finally got a firm diagnosis when the dealer's mechanic took his diagnostic computer for a ride to log the problem when it occurs. Problem is a mismatch between the rear axle ratio programmed into the computer and the 3.73 rear axle I put in. Donor car is not available, but the engine, transmission, computer and all came from a '94 Roadmaster. Mechanic logged a speed reading of 75mph from the computer when the car is actually doing 50. So when I get the El Camino up to 72-73mph the computer thinks I'm up to its 110mph limit and cuts off the injectors. But he can't reprogram the axle ratio.

Have any of you dealt with reprogramming something in the factory computer? (94 Caprice/Roadmaster, OBD I, but should be able to program it through the diagnostic port)

Thanks

acauth1 · Posted: Mon Jun 04, 2007 8:40 am Post subject:

You need a program similar to Tunercat: http://www.tunercat.com and the correct definition file for your pcm (pcm_ee.tdf). You will also need a cable to connect from your computer to your pcm, you can buy one from AKM or make your own, I think he still has instructions on his site here: http://www.akmcables.com
Yo ucan download a trial version of tunercat from their site but you will still need the def file. If you need a copy let me know.

Robert
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El Camino Central Founder/AdministratorAuto A/C & Electrical Shop Owner, ASE Master

Mr86Camino · Posted: Mon Jun 04, 2007 11:40 am Post subject:

If you don't want to invest in the software and cables the easy cure would be to get in touch with Norm at Affordable Fuel Injection.

Norm knows a LOT about fuel injection. He can customize your program to fit your needs.

I bought my FI system from him and could not be happier. He has customized a few things for me and tweaked it to fit my Elky.

I have no idea what he would charge. It can't hurt to ask him.

The web site is:
Affordable Fuel Injection
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1986 El Camino
1985 Porsche 911
2008 Infiniti G35X (wife's car)

greywolf · Posted: Fri Jun 08, 2007 9:02 pm Post subject:

Thanks. My donor car is a year that can program the computer thru the diagnostic port. I could get to it with TunerCat--and was looking for a good excuse to buy a laptop anyway Wink

I got thru the engine swap without buying any new tools, so I guess now is the time...