Bad Electrical gremlin

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Pntaste4evr99
Winestone Cowboy
Posts: 341
Joined: Thu Mar 26, 2015 4:12 am
Location: Lake Stevens WA

Bad Electrical gremlin

Post by Pntaste4evr99 »

Hi everyone, I've been having a problem with a hesitation and miss for a week or so, now car won't start.
It's a Rob 550 tune on a 20g swap, somewhat common with ppl on here. For around 15k miles everything was good, no problems at all. Only in the last couple weeks something started to slowly die.
Car first would just miss every once and a while, when driving normally. Then would tweak out and hesitate bad under boost. Then had hard time starting, now won't start at all. I consider my self a patient man, but I lose my cool with eltrical problems.
So far only threw one code, 32 so I replaced that on th side of the road when it first died. No change.
So far I've replaced:
O2 sensor
Swapped multiple coils to diagnosis, no change
Cam and crank sensors
Ignitor
3sets of plugs (due to fuel soak)
Spark plug wires.

And so far and checked or swapped:
ECU (swapped another 20g with Rob 550, no change)
Robs ignition converter-good
Timing-good
Swapped to coil on plug-no change
Ohm and volt readings on multiple sensor and ECU pins-so far good
Ignition relay under dash-swapped with another, so assuming good
Fuses-good
Ignition cylinder-good

Am I missing something to check??? I've exhausted mine and friends of mine ideas.
Car would only throw a spark at the coil AFTER turning key from start to on(if that makes sense)
Car started ONCE since all this but missed, ran rough and backfired a lot then died. I'm going to check the fuel regulator and some more stuff tomorrow but I've ran out of ides to search for.
I know there are a lot more ppl on here smarter then me, so hopefully someone can help

I'll entertain any ideas so don't be shy.
Thanks ppl
94 Winestone SS 5MT Rob 550 20g. (Pickle)
Original WA car with 460k miles and climbing
Legacy777
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Re: Bad Electrical gremlin

Post by Legacy777 »

The fact you don't have spark would lead me to believe it's crank or cam sensor related, but you said you replaced them. Did you check continuity of the wiring from the wiring harness back to the ECU?

Do you own a multimeter? If not I suggest getting one so you can do some checks on the wiring and sensors. Have you downloaded the factory service manual from me?
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
Pntaste4evr99
Winestone Cowboy
Posts: 341
Joined: Thu Mar 26, 2015 4:12 am
Location: Lake Stevens WA

Re: Bad Electrical gremlin

Post by Pntaste4evr99 »

Thanks for replying Josh, yeah checked continuity between stuff, all checks out. We have the old school Subaru manuals at the shop so that's where we're getting our inputs. And yes own a multimeter. The only thing that was weird was a couple ohm test out of the ECU were low that what the book wanted, but of course I can't remember which pin they were now....
94 Winestone SS 5MT Rob 550 20g. (Pickle)
Original WA car with 460k miles and climbing
Legacy777
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Re: Bad Electrical gremlin

Post by Legacy777 »

If you can retest or remember which ones were out of spec let us know.

I'm kind of at a loss to what to suggest next without more info. If you can easily revert to a stock ECU that might be another troubleshooting step you can take.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
Pntaste4evr99
Winestone Cowboy
Posts: 341
Joined: Thu Mar 26, 2015 4:12 am
Location: Lake Stevens WA

Re: Bad Electrical gremlin

Post by Pntaste4evr99 »

I haven't plugged in my stock 22t ECU because I swapped in a good running 20g with same Rob chip and it did the same thing, not start. Then plugged my ECU into the car that ran fine and it started right up and ran fine, who th my ECU. So that's why I'm thinking it's not a ECU problem. I'm going to double checked all my grounds and small stuff after work tonight, hopefully I just missed something obvious, but thanks again for replying, I've been reading a lot of your post/inputs from the last couple years to get a better idea what's going on.
Just wanted to say thanks again
94 Winestone SS 5MT Rob 550 20g. (Pickle)
Original WA car with 460k miles and climbing
Legacy777
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Re: Bad Electrical gremlin

Post by Legacy777 »

You're welcome.

Keep us posted on what you find out.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
Pntaste4evr99
Winestone Cowboy
Posts: 341
Joined: Thu Mar 26, 2015 4:12 am
Location: Lake Stevens WA

Re: Bad Electrical gremlin

Post by Pntaste4evr99 »

Image

I think I found it! The engine harness ground on the back on the intake was loose. Tightened that up, pluged everything else in and fired right up. I didn't run it long cause had the timing covers off, but ran. Tonight after work gonna put the rest together. Hopefully that does it.
94 Winestone SS 5MT Rob 550 20g. (Pickle)
Original WA car with 460k miles and climbing
impostor
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Location: Omaha, NE

Re: Bad Electrical gremlin

Post by impostor »

Ah, the importance of grounds! Nice work finding that. When I got my swap up and running I had a loose ground also. Engine would die only when turning right.
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