Re: Going under the knife
Posted: Sat Jan 15, 2022 2:49 pm
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Going under the knife
Page 35 of 39
Re: Going under the knife
Posted: Sat Jan 15, 2022 2:50 pm
So, all these issues are theory?
Re: Going under the knife
Posted: Sat Jan 15, 2022 3:04 pm
Theory?
The fuel tank really did leak (fix in work), the VR sensor really was wired backwards (fixed) and I when I hooked everything back up and cranked for spark I still wasn't getting consistent spark when cranking to check the tooth offset with the timing light.
So while I'm working the tank issue I am testing the coil pack in as much isolation as possible. In my pre-retirement life this was called Unit Test.
Max
The fuel tank really did leak (fix in work), the VR sensor really was wired backwards (fixed) and I when I hooked everything back up and cranked for spark I still wasn't getting consistent spark when cranking to check the tooth offset with the timing light.
So while I'm working the tank issue I am testing the coil pack in as much isolation as possible. In my pre-retirement life this was called Unit Test.
Max
Re: Going under the knife
Posted: Sat Jan 15, 2022 3:08 pm
Crank sensor out of phase OR too far from the source?
Re: Going under the knife
Posted: Sat Jan 15, 2022 3:11 pm
The tooth log shows that I'm getting good signal from the sensor and the log shows good sync.
Max
Max
Re: Going under the knife
Posted: Sat Jan 15, 2022 4:44 pm
Sounds like signal interference. Chased that for days on my buddies efi sandrail
Re: Going under the knife
Posted: Sat Jan 15, 2022 5:19 pm
^^^^
Unless its ethanol free gas it starts insta-varnishing your plugs after ~6 months, sometimes less.
A fresh set of plugs should work briefly though.
berrymans B12 chemtool might help, but might dissolve any epoxy in your fuel system...
...contains acetone, 2-propanol/IPA, and MEK. don't get it on a cut. or paint...
... may take awhile to stop screaming either way.
You can clean varnished up plugs with it, works great to clean/flush injectors as well.
Re: Going under the knife
Posted: Sat Jan 15, 2022 5:29 pm
Maybe you have a bad coil driver
Re: Going under the knife
Posted: Sat Jan 15, 2022 5:31 pm
Believe it not, the local Maverik sells ethanol-free gas. I buy it for the snow-blower and my tractor. As it happens I bought some a few weeks ago and that is what I'm using in the VW. In any case, my entire fuel system is new or, in the case of the injectors, freshly cleaned.
Max
Max
Re: Going under the knife
Posted: Sat Jan 15, 2022 5:41 pm
That may be where I'm going next. Mario modded my ECU several years ago when I went to wasted spark with the IGN-4. And it worked fine that way for several years of daily-driving. He put a sticker on the case showing which pins to use. I'm using a fresh pre-made harness from DIYAutotune so I guess it's time to make sure I'm using the right pins.
I used noid light across the 1/2 and 2/3 pins (1 and 3 are signal while 2 is +12v) and it lit up when it should have. I figured that meant I was wired up correctly.
Max
Re: Going under the knife
Posted: Sun Jan 16, 2022 12:08 am
Which one is ground?
Re: Going under the knife
Posted: Sun Jan 16, 2022 5:38 am
Time to triple check your wiring. If a new harness was installed that would be the place to start - check each lead (end to end) for low resistance and no ground path. Your +12v coil check with the test light should be the positive (center pin I believe on your coil) to engine ground, or center pin of the cable connector to ground - engine ground. A painted tin surface isn't a good ground - choose bare unpainted metal, like the bare aluminum block. I'm guessing something is amiss in the ECU to coil wiring harness?
Jeff
Jeff
Re: Going under the knife
Posted: Sun Jan 16, 2022 8:08 am
From DIYAutotune ...
Yes, the harness is in question.
Max
Yes, the harness is in question.
Max
Re: Going under the knife
Posted: Thu Mar 10, 2022 3:44 pm
Hi guys. Didja miss me? 
So I've got the fuel tank issues whipped (unless it springs a leak somewhere) and today I started the engine.
I apparently have a pretty big air leak somewhere in the TB because as soon as it fired the RPMs went the ~3700 and stayed there. OP went to 60 psi and one of the oil filter fittings leaked. According to the CLT and MAT it was about 20 degrees at the start. Straight 30 weight oil. Putting my hand over the intake brought RPMs down to around 2k.
I let it run for a few minutes to get some logging.
What does this mean? The fuel system and ignition both work.
Max
So I've got the fuel tank issues whipped (unless it springs a leak somewhere) and today I started the engine.
I apparently have a pretty big air leak somewhere in the TB because as soon as it fired the RPMs went the ~3700 and stayed there. OP went to 60 psi and one of the oil filter fittings leaked. According to the CLT and MAT it was about 20 degrees at the start. Straight 30 weight oil. Putting my hand over the intake brought RPMs down to around 2k.
I let it run for a few minutes to get some logging.
What does this mean? The fuel system and ignition both work.
Max
Re: Going under the knife
Posted: Fri Mar 11, 2022 5:29 am
Maybe a vacuum fitting left un-plugged? IAC valve? Definitely sounds like an air leak.
Jeff
Jeff