HELP! Evo 8 ecu, 4500 rpm then stalls

[ra_guy]

Ok, so I don't exactly have a dsm, what I do have is a dsm 6 bolt with a 2g head installed in a mirage, run by an evo 8 ecu. This is a completely fresh build, so I'm not sure where to start and searches have yielded no answers... The car will start, however it shoots to 4500 rpm, hangs for a few seconds, then stalls, I can keep it alive with the throttle. I've checked the idle stepper, it's fine, and no leaks past the throttle body, so I imagine it must be an ecu problem. I'm running dw 1300cc injectors and e85, injectors scaled to 886, fuel pressure is right at 40psi, maf scaled to match another's stock 2g scaling as that's what's installed.

Any suggestions?

* I should add, the BISS is bottomed out.

 

[delta448]

Lower the entire cold start enrichment table by the same percentage that injector size increased over the stock Evo injectors, set the BISS correctly and verify the ISC position is not maxing out.

 

[Broke4speed]

What diagram did you use to make your patch harness? Some of them have the ISC coils reversed. Here's a correct one (using this one on my own Colt/4G63T):
http://www3.sympatico.ca/tchaad/EVO_DSM pinout.xls

 

[1G Eclipse94928]

Ok, so I don't exactly have a dsm, what I do have is a dsm 6 bolt with a 2g head installed in a mirage, run by an evo 8 ecu. This is a completely fresh build, so I'm not sure where to start and searches have yielded no answers... The car will start, however it shoots to 4500 rpm, hangs for a few seconds, then stalls, I can keep it alive with the throttle. I've checked the idle stepper, it's fine, and no leaks past the throttle body, so I imagine it must be an ecu problem. I'm running dw 1300cc injectors and e85, injectors scaled to 886, fuel pressure is right at 40psi, maf scaled to match another's stock 2g scaling as that's what's installed.

Any suggestions?

* I should add, the BISS is bottomed out.

Your ecu needs to be tuned for injectors, fuel, etc. You tuning speed density or wideband?

 

[ra_guy]

Ok, after fiddling with it all day, I finally noticed the check engine light, doh!... Apparently the ecu is not getting the cam or crank signal, at least according to the codes read in evoscan. I've ohmed them out from the plug to the ecu and they're making it back just fine. for giggles, I checked voltage at the plug (big black=ground, red=12v, black 5v, white 5v). Is it possible I've got a bad cas? Would it really even start if there were no signal to either input? It's a green top cas if that matters... As far as a patch diagram, I didn't necessarily use one... I more matched pinout to pinout and cross-referenced with info posted on geekmapped since I'm using a lancer gsr harness... Thanks for the replies guys

 

[Broke4speed]

What ROM are you using? Only the EDM 9653 ROM is compatible with the 1G CAS. The USDM 9417 ROM will throw a cam/crank code, like you're seeing now. The EDM evo 8 cam reluctor is different than the USDM one.

 

[ra_guy]

Oh geeze, your right, my bad. I flashed back to the evo 8 stock rom with my modded fueling just before seeing those codes to make sure it wasn't the tephra v7 rom causing issues... Nevermind the cas thing ...

 

[Broke4speed]

I'd try reversing the ISC coil wires, it seriously sounds like they're reversed. The evo ISC seems to work opposite the DSM one. My ISC is closed at operating temp, and counts down like it should in the datalogs. Some of us over at DSMECU who have done this swap experience the rising idle thing, and it's usually always the isc wiring.

 

[ra_guy]

What's the proper function of the isc? It goes to full open when the key is turned to on should it close instead? Even with it manually fully extended and closed and unplugged, the idle bounces between 3500 and 4k rapidly. It doesn't die though....

 

[Broke4speed]

Well, it opens up to help start the car, then slowly steps down based on engine temp. There should be some ISC settings in the xml to show what the initial step should be. Compare that to your logs and see how it behaves.

How's the base timing? If it's too high, it's definitely going to affect the idle. Also, due to the smaller 2G MAF, it will affect the load scale, so you may be at a higher point than the evo 8 maf would be, and getting some really high timing.

 

[ra_guy]

So if it were reversed, it would go full closed at key on right? Just to rule that out. I can't set base timing because it dies after a few seconds... Is there another name for the cold start enrichment table? Would that cause the rpm to stay so high? I just reread your post... I think you may be on to something, I'll look more closely into the load values and timing if I can get a log... That sounds pretty logical...

 

[Broke4speed]

Yeah, it'll be full closed at key on if they're reversed.
Sounds like you've got a mechanical issue somehere. It sounds like it's getting choked off after the ISC does it's first cycle. The cold-start enrichment can only add fuel, so the idle wouldn't get that high without air coming from somewhere.

 

[ra_guy]

I'm so damn frustrated I can't even think properly, my troubleshooting skills are severely hindered.... The only thing I can think of is egr, I have the external port blocked off, but the one on the head, inside the intake manifold, is not... Could that be an issue at all?

If I were to post the before and after .hex files, would someone be willing to look them over to ensure I didn't miss anything going from the original injectors to the 1300s and e85?

*Meant to add, I had two sets of eyes and ears extra today to listen/look, there were no obvious hissing/unusual noises/sights to be heard/seen ...

 

[ra_guy]

It was a leak... A very big leak... I installed a 1g dsm intake manifold gasket by mistake. How I didn't notice this during the build process, I have no idea, but I do have the proper gasket in there now and I can get it to idle. My problem now is it's far too rich, afr showing 12-13 points on the gasoline scale. So my next step is to tackle that, but first I have some other leaks to address, namely the throttle body shaft seal.