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Discussion Starter · #1 ·
I'm at my whits end.

I finished building a hybrid engine. Ran great for the first 200 miles.

The problem occured driving home when the driverside wheel unbolted itself and shredded up the front wire harness(no lines were severed but about 15 fused together). Never trust a friend to torque your luggs!

All mechanicals were repaired; fender, wheel well, rim.

After that the engine wouldn't start. Problem ECU was fried. got a new one.

So now the engine idles very roughly and only when the MAF is left unplugged. as soon as its plugged in the engine dies. The MAFand MAP sensors have all been eliminated from being the problem. Used a similar wrx as a test. All wiring has been repaired. Checked and rechecked. I have replaced both cam and crank sensors with used replacements. No effect. Compression test came back with all 4 within spec of each other.

Other noticable changes
When running on lambda (unplugged MAF) at a rough idle the tailpipe is very rich. lots of smoke.

Am i correct in assuming if it were a burned out injector or coilpack it would run on the MAF but with a cylinder miss. If it was the fuel pump, pump controller it would not run at all. Is this a global problem all cylinders.

Here's a list of engine mods.
2004 USDM 2.5L Block (stock 2004 internals)
2002 USDM 2.0L Heads
TGV deletes
catless up-pipe
Header unequal
stock turbo
stock injectors
COBB AP
2008 oil pump
low temp thermostat

Please help im loosing my mind.
 

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Discussion Starter · #3 ·
Crimp and soder with weather shrinks for the wires. i'm a phone and cable man. Outdoor wiring is my job. As for the ECU i had my friends AP married to it for a few days. tried every map that i had stored on my computer that was set up for the TGVs (ie toggles and P-codes).

That was one of my first thoughts. TGVs if no motors sends the unit into limp mode, but even still its not going to effect the fuel ratios and or ignition timing. Right?

I'm waiting on COBB now to unmarry my AP from my old ECU, and sent it back. This problem has been keeping that car down for months. I need it back for my sanity at the very least. After it comes back i want to make a bunch of datalogs on what happens when the MAF is plugged in and the engine stalls.
 

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Discussion Starter · #6 ·
The tune that was running on that wrx was only a 91 oct stage 1 tune from Cobb. I was 800 miles away from my first protune. Cobb and the tuner had confirmed that map would be fine until I had 1000 miles on the engine.
 

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Maybe there is an issue with your front O2 sensor. I find it hard to believe you do not have a check engine light. Could be you forgot to hook up a couple grounds.
 

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Discussion Starter · #9 ·
Very much could be a ground or an open circuit. The problem is which one or ones. It all comes back to the agent of change. Cause; tire friction ground down shielding on aprox 15 wires above the drive side wheel. (front wire harness.) effects; engine stall, ecu malfunction dead(assumed power surge from 12 volt feedback).

Only got it to run once today after a lengthy cranking and accelerator coaxing. But I did notice something strange. My tachometer shows no rpms unless I hear a detonation. Or it might be opposite. I see the tach bounce momentarily and I hear detination.

I'm curious to know how the tach acquires a signal to move. Is it off of a cylinder 1 spark. Or off a crank or cam sensor. I'm guessing I need to check grounds on that circuit. And leads as well. Along with the sensors themselves. And ideas how to verify those sensors? I should get my COBB AP back this week.
 

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Discussion Starter · #12 ·
BAZINGA!!!!!!, Finally your last post was the right call. After pulling hairs out for 6 months, and some help from the good people at IAG in Maryland. the error had been located. it was another set of fused injector leads which when fused lowerd the resistance on 3 of the injectors and caused them to act like 850cc injector scaling.

Pain in my ass. so its finally running and its at around 850 miles. running as well as can be expected for a Hybrid motor with a somewhat stock tune. thanxs for your help Donkey. gonna start another thread on 2.5 hybrids, thermodynamics and dynamic advance
 
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