For the mechanic Guru (Subi problem)

[ftp2leta]

Hey guys.... I have posted this one of some Subi forum and on the Yahoo list but why not try here....

I'm stump. For my 96 conversion I did an older one, 2002, car from an old lady with no miles.

Did the usual HG and seal replacement and bla bla bla..

Problem: #1 is not firing properly at idle, look fine at 2000rpm. Of course it's not running smooth, not to bad but not perfect at all.

Ok, of course I did everything and replace everything, I can name it if you want but...

So unplugging the #1 injector at idle does nothing. Spark is good and coil, wire and plug where swap and all new anyway. Replaced/swap the injector same problem. Compression test is fine but the leak down test shows me a small leak on the intake side. Checked all valves adjustment and all is fine.

Pulled the injectors a bit out to see them spaying and they both spray at idle on this side, check every single wire from ECU to injector plug.

I read somewhere that a bad idle control valve could create a similar issue. both OS are unplug for testing and anyway it changes nothing if hooked. Ground is fine.

All other cylinder are acting normally if unplug, engine goes way to low. Strangely idle is at 700rpm or so.

No i didn't drive the van yet and yes I should.... but this engine as been working in the shop for more then 2 hours now.

Any suggestions?

Thanks, Ben
_________________
Working with rust, grease, dirt and dust is a sad truth.
------------------------------------------------------
FI part for sale: http://www.benplace.com/parts_sale1.htm
My site: http://www.benplace.com/vw2.htm
Subi conversion: http://www.benplace.com/vanaru_eng.htm
Youtube http://www.youtube.com/user/ftp2leta

[insyncro]

I had a low idle and stumbling issue with an early one...it was building crankcase pressure and was not able to relieve it.

I would describe it as a mild choking.

Not saying this is your issue, just sharing.

Hope it helps.

[Honuak]

If have not done so already get a code reader (you can get one for less than $15.00) and check for trouble codes. A code will put your subaru motor in to limp mode, misfire. Many subi conversions (mine included) did not address things such as VSS, grounding, OX sensor etc correctly, Auto vs Manual confusion can be an issue as well.
With the code reader you can see what the problem is and then reset the ECU.
Usually you can drive the van normally for awhile before it goes back into limp mode but eventually the issue should be addressed. Once I fixed mine (grounding, VSS etc) I gained about 2 mpg and so far no more limp mode (fingers crossed)

[ftp2leta]

For sure I have an OBD2 reader... the code are the standard one.

No pressure in the case.

Ben
_________________
Working with rust, grease, dirt and dust is a sad truth.
------------------------------------------------------
FI part for sale: http://www.benplace.com/parts_sale1.htm
My site: http://www.benplace.com/vw2.htm
Subi conversion: http://www.benplace.com/vanaru_eng.htm
Youtube http://www.youtube.com/user/ftp2leta

[61Scout]

If the misfire isn't following the plug, wire, or injector that would have me looking at valves or something systemic. Sounds like you've already checked the mechanical condition of the valve train. Do you have a borescope to look into the cylinder?

Bypassing all the easy stuff... I'm going to take a wild guess here and say that you've got a cam pulley walking on the shaft and it's messing with the CMP which in turn is causing the misfire.

-Kevin
_________________
1986 Westfalia Weekender Wolfsburg, RJE 2.3
1985 Tin Top, Subie 2.2 + 5MT
Floppy Mirrors no more: http://www.thesamba.com/vw/forum/viewtopic.php?t=653018&highlight=
Remove the front spindle nut with ease: https://www.thesamba.com/vw/forum/viewtopic.php?t=679567&highlight=
Remove the rear wheel bearing housing without messing with the big 46mm nut: https://www.thesamba.com/vw/forum/viewtopic.php?t=679507&highlight=

-Nec Spe, Nec Metu

[insyncro]

Stumper
You will find out why Ben, I know you will.
Looking forward to hearing what it is and learning more from you.

Go gett'em Tiger.

[WestyBob]

Bad knock sensor ?

Made my subie do funny things once.

[ftp2leta]

All I can see is a weakness in #1 compression, 160 instead of 185.

Time to have a drive

Ben
_________________
Working with rust, grease, dirt and dust is a sad truth.
------------------------------------------------------
FI part for sale: http://www.benplace.com/parts_sale1.htm
My site: http://www.benplace.com/vw2.htm
Subi conversion: http://www.benplace.com/vanaru_eng.htm
Youtube http://www.youtube.com/user/ftp2leta

[insyncro]

[ftp2leta]

(posting for the second time????)

Problem fixed... a hard ride at 90mph and idle was back to normal. Compression also.

Crap under intake valves... grrrrrrrrrr

Ben

Paint - interior - Conversion - transmission


Link

_________________
Working with rust, grease, dirt and dust is a sad truth.
------------------------------------------------------
FI part for sale: http://www.benplace.com/parts_sale1.htm
My site: http://www.benplace.com/vw2.htm
Subi conversion: http://www.benplace.com/vanaru_eng.htm
Youtube http://www.youtube.com/user/ftp2leta

[dobryan]

Glad you got it worked out. 😀 Thanks for posting the resolution. I guess the leakdown was the clue, enough compression loss at idle to kill the power from that cylinder.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[hans j]

Nice job. Old lady with clean low mileage car usually means it hasn't been driven very hard and will get issues like that. Italian tuneup is needed on most cars! Unless you have seen the VW commercial of the old lady selling the Mk3 golf
_________________
1986 Canadian Syncro Westy TDI - 1989 Syncro Single Cab - 2001 Audi S4 - 1981 VW Caddy ABA - 1980 VW Caddy EV - 1973 VW T-181

[ftp2leta]

[pedrokrusher]

[ftp2leta]

[insyncro]

[pedrokrusher]

[boroko]

can't get 90mph? BS!

This is a cruise back from Florida to Michigan in a Westy Syncro with a stock 2.1. When the picture was taken, I'd been doing that for hours. And yes, the odometer is in miles, not km. Only major repair was a head reseal around 100k.
It'd go about 95mph before i wasn't comfortable with the handling, so I backed down a bit, but the motor didn't complain.
Just saying... that was before I learned they weren't suppose to do that.
Bo
_________________
'87 SyncroWesty: Smokey the Turtle, '85 SubiWesty: Chappie, '84 GTI, '86 GTI in full Rally trim,
previous: 2 Syncro tin tops, 2 Vanagons, 3 busses, 3 Ghias, 2 Jettas, a 411, a gas and a diesel Bunny and about 25 Beetles, one that only drove left.

[boroko]

I know the issue has already been solved, and thankfully in a sweet way, but here is another tidbit that I learned from a trusted mechanic that I was working with lately.
He was having a problem with a mid 2000's subi that was going into retard from the knock sensor. A new sensor and proper torque did not help. He had found from one of his industry contacts that there were some of them (somewhere around 2002-2006) that had input protection circuitry on the ECU that failed and allowed too much of the knock signal through tripping a knock detect. The fix was to hook up high value resistor (around 560K ohm) from the signal line to ground to pull down some of the signal noise. The actual value was determined with a decade box or a variable resistor and watching the knock response. In the end, we got the right value and soldered it in. It allowed the knock function to still work and it solved the problem. All this is to say that there is a weakness is some of the ECU's and it will drive you nuts if you don't know about it. If anyone is having an difficult unresolved problem, I can get the exact years and procedure. Kind of an advanced procedure, but I have seen it answer a quirky problem that I had never seen.

I'm hoping to have my conversion done by spring for Busses by the Beach in May here in Michigan.
Bo
_________________
'87 SyncroWesty: Smokey the Turtle, '85 SubiWesty: Chappie, '84 GTI, '86 GTI in full Rally trim,
previous: 2 Syncro tin tops, 2 Vanagons, 3 busses, 3 Ghias, 2 Jettas, a 411, a gas and a diesel Bunny and about 25 Beetles, one that only drove left.

[ftp2leta]

Thanks Boroko, interesting.

Especially that the knock sensor code was often a ghost code on the early 2.5L SOHC.

Ben
_________________
Working with rust, grease, dirt and dust is a sad truth.
------------------------------------------------------
FI part for sale: http://www.benplace.com/parts_sale1.htm
My site: http://www.benplace.com/vw2.htm
Subi conversion: http://www.benplace.com/vanaru_eng.htm
Youtube http://www.youtube.com/user/ftp2leta