brick wall at 4500 rpm

[losermakesgood]

Ok. Background first. Finally got the car running. Turned out to be an ecu issue caused by ecm tuning which they fixed for free. Great people. Anyway.

I get it running and revving it up it hits a brick wall at 4500 rpm. Hasn't been on the road in some time. New ecu with ecmlink v3, fuel pump, injectors, plugs, wires, etc. All works. No leaks. Haven't even boosted yet. Went through the typical check this/that routine. What gives?

Moving in 4 weeks and need it running. Any help or advice is greatly appreciated.

 

[losermakesgood]

OK I'm a noobtastic idiot. Ecmlink had launch control on. Now to fix the nasty idle issue and get it put back together. I tested the isc and it came out 19 ohm across all proper contacts. Is that correct?

 

[ExplicitCC]

Mine hits a wall at 6K RPM's but I think I need to install a Evo maf, and tune it with a DSM link, you can see the technical page they have a thread on the idle sure problem, it fixed mine, good luck with the idle

 

[holeshotmoe]

For the original ISC (silver body with brown socket), values measured between pins 1&2, 2&3, 4&5 and 5&6 should be 28-33 ohms. The newer (black) ISCs should measure about 40 ohms across those same pin combinations. Values below this (i.e., 19 ohms) are out of spec. Several websites can be found that state the lower values put excessive load on the ISC driver chip(s) in the ecu, and will eventually lead to their failure. They also state the newer, black ISCs with their higher resistance are easier on the driver chips.

 

[losermakesgood]

I have the black isc I bought last year because my drivers on the ecu kept getting blown. Now after having them repaired twice I disconnected it and my idle is fine once warm. But it's a major pita to start and have to wait for it to warm up. But at least it starts now lol. Just have to dig into a few issues to be able to drive it. I have read every article about idle surge and brick wall and none have pointed to my problem yet.

 

[holeshotmoe]

The 19 ohms on the ISC is a problem. It is half what it should be. The windings may have begun to short and will likely get worse. It is the low or zero resistance that cooks the driver.
(I have read of FIAVs leaking and fouling the ISC, but I'm not real familiar with that. I'm guessing the antifreeze gets into the electrical side of the ISC but not sure how.)
Also, have you checked the ISC lines to the ECU to make sure there is not a short there? This could definitely pop the drivers too.

 

[slugsgomoo]

yep, if your fiav leaks it'll eventually fill the isc with coolant and then your ecu will need to be sent off for repairs. I'd recommend ecmlink.com for repair service these days, for what that's worth. If your ISC is not ohming right you should buy a new one and also pull the ecu and inspect for burnt drivers visually.

There's a faq on dsmtuners on how to delete the FIAV for free (well the cost of a set of throttlebody gaskets). Unless you're driving your car north of the arctic circle, I highly recommend it, fiav is a total waste and has been the root cause of at least 3 murdered ecu's I've had to diagnose in the last couple years. Basically it's like a balance shaft belt. Might make you a bit more comfy sometimes, but when (not if) it goes it's going to be pricey.