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Yet another isc question...

Gtpdz

Well-known member
Joined
Mar 12, 2015
Messages
140
Location
Gig Harbor, WA
So after getting my rebuilt t body a few days ago, I found out that the old isc was bad, so anyone running without an isc but still with FIAV? How's the cold start looks like in this configuration? Mine has a very low cold start rpm...

Also, how much voltage should I get from the isc plug? I think I'm probably having a bad driver in ECU as well... When I switched to a new isc the rod does not move even my logger shows it goes from 0-120.
 

slugsgomoo

Well-known member
Joined
Oct 16, 2003
Messages
3,776
Location
Tacoma, WA
the most common reason for an ISC to be dead is that the POS fiav has leaked on it, which will also murder the drivers inside the ECU. Worth pulling it out and verifying that they're not toasted.

My general process is to do the free FIAV delete (google search "free fiav delete dsmtuners" and you'll find a good writeup), replace the ISC, and get the ECU repaired (if needed). With no FIAV, but a working ISC I've never had an issue, but I've not had to run any of my cars down below about 12*F.
 

Gtpdz

Well-known member
Joined
Mar 12, 2015
Messages
140
Location
Gig Harbor, WA
Quoting Dark_Horse:
Did you confirm that the ISC was good with your multi meter?



ISC is good, turns out the rebuilt throttle body I got have already done free fiav mod to shut it off, hence giving me cold start problem. Swapped back the old FIAV and problem solved, probably it's a bit leaky but I'm not having the isc pluged in at the moment so i won't be worry about further damage to the ECU. I do believe the isc driver is dead though... Anyhow there isn't much problem without a isc at the moment except for rpm drops too quick when letting off the gas...

It will be like that for the time being, when I get my ECU check and repaired I will hock everything back to see how it goes.
 
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