DSMLink help please

grnchevyz · 09-30-2006, 07:09 PM

Ok, so long story short, swapped ECU with a 95 Eprom with v2.5 chip in it. Car, however stable, idles at 2300rpm and won't go any lower.

Here is what I checked/did:

1- ISC checks out OK (~30ohms across all pins)
2- TPS checks out OK (.52v position at idle and 5v at WOT)
3- Boost leak - NONE
4- Vac leaks - NONE

If I put the old ECU in it stabilizes.

Ok so 2 questions,

1- Short of a BAD ecu, (the caps are new and there seems to be no damage) what could cause this idle?

2- I need pointers on how to get stared with Link. I read and read the manuals and docs and am unsure of what the values actually do...more so on the Fuel, Airflow (MAF/VE) values. What should I be doing to set LO throttle and WOT operation?

I should mention that the car will not launch. No matter what rpms I use, it will simply not launch, it just bogs down and then I can drive it (3-4s pause).

Profile is up to date and am running 14lbs on the EVO until I learn how to fine tune.

Thanks in advance!

donmagicjuan · 09-30-2006, 11:52 PM

Is the old ECU your original non-EPROM from the '98? If so, are you saying that idle returns to normal even with the uncompensated 550cc injectors?

It might help if you were to list your current settings in DSMLink. Link isn't exactly my baby, but maybe some of the gurus on here could offer something helpful after taking a gander. Have you tried your luck on the DSMLink forums yet?

grnchevyz · 10-01-2006, 07:26 AM

I'll post those settings...and yes even with uncompensated 550's it runs ok...a little rough but not at 2500rpm.

I tried the DSMLink forums but everything they told me to do, I did and still high rpms..

I'll get a 30 seconds idle log for here today.

playitlouddsm · 10-01-2006, 12:41 PM

You haven't messed with the biss at all have you? Log ISCposition and Learnedidle and see what they are currently at.

grnchevyz · 10-01-2006, 12:54 PM

I haven't messed with it but I replaced the TB with another one as my old one blew the FIAV gasket.

LearnedIdleADJ sits at 144
ISCPosition hovers around 19

playitlouddsm · 10-01-2006, 01:34 PM

ISCposition is a little low, should be closer to 40. I don't see this causing your high idle though. Are you positive that your TB isn't sticking open at idle? Have you adjusted the throttle cable?

grnchevyz · 10-01-2006, 02:57 PM

Pretty sure the Plate isn't stuck open...I'll double check and re=post...I'll have logs in a little bit.

flinguist · 10-01-2006, 06:19 PM

Sounds like it may be an ecu problem. Ask around on the DSM link forums- www.dsmlink.com/forums

Gary 420A RS · 10-01-2006, 06:23 PM

maybe your idler pulley? iam pulling this out of the hat. mine was this it idled at 1500k the 2k and one day 3k. i could drive it and as soon as i put it in gear it would go back down. but in nutrual it would go up. adjusted that and now its fine.

grnchevyz · 10-01-2006, 07:16 PM

You know what...I was thinking Idler pulley too...just would be one heck of a coincidence. I'm changing it next week anyway. Haven't got my laptop back yet...as soon as I get it I'll post idle, slow run adn 3rd gear pull logs.

AL92 · 10-07-2006, 11:47 AM

I had a bad chipped ecu I think and it caused bunch of weird problems.I got new pro done ecu and new dsmlink chip to make sure it would be fine and it is. You need to push the idle thing in misc to reset the isc. Also you may need to tweak your throttle cables to make sure you are not pulling idle higher. The FIAV circuit can also fail. Mine is welded shut.
Also I don't think the 2g ecus have any cap problems like the old 1g ecus. But not everyone is capable of soldering the eprom socket in there and not messing things up.
Also vaccum leaks can cause idle problems. I did throttle shaft seals and found a leak at throttle body gasket and at intake manifold. Found them with a pro smoke machine quickly at buddies garage.