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Sun Aug 03, 2025 10:58 am

Whenever I start my van it turns over and runs great for about 15 seconds before quickly choking up and dying, after I repeat this about 3 or 4 times it will idle perfectly with no issues and if I turn it off and start it again after running it for a while it will start just fine with no signs of choking. Has anyone ever had this happen or have any ideas what it could be?

PS giving it gas when it has just turned over helps it run a little longer but it will still choke out 2 or 3 times before running without issue.

Sun Aug 03, 2025 2:35 pm

What year is your Vanagon?
Need more info to help you-, like, are you losing fuel or spark?
One thing that can cause your symptoms is the braided shield coax cable of the O2 sensor shorting out the inner signal wire on the O2 wire-when this happens, you’ll run really rich and usually die out. The braided coax shield wire is grounded all the time, so if it pierces the inner signal wire, the ECU in turn runs the engine really rich.
You can easily check this with a meter. Take a resistance reading between the inner signal wire and a good ground. Should not have a reading, you ideally read the meter as an open circuit if the shield wire and inner wire aren’t making a connection.
If you get a low resistance reading, the repair is to trim the coax cable at its end away from the inner insulation of the signal wire. It’s usually the last 1/2” or so that pierces the signal wire.
Here’s a picture of the body harness you’d want to check.

Sun Aug 03, 2025 3:29 pm

I'm following this with great attention as got the same thing happening on my free van, 2.1L Digifant, like the IACV is dead .
Unless I rev it in neutral really hard a few times, it won't idle and die, hard to even rev it sometimes.
I changed just about everything on this damn EFI, it's the first van that I never solved.
New-ish harness, swapped every components :
AFM, distributor, several ECU, several ICM, a few coils, new plugs, wires, cap, rotor, new FPR from Mansi, fuel tank is clean and resealed. New Bosch fuel pump, rebuilt/cleaned injectors. New OXS, new ground strap, clean ECU grounds. Temp2 sender tested good.

The engine had destroyed valve adjuster screws, so I replaced these , added lash caps and rocker shims, and adjusted the valves.

Just unreal. I haven't taken compressions but I don't see how that would do this issue. Engine uses a lot of oil, oil pressure hot at idle is crap, so it's prolly tired but still, it shouldn't do this idle issue.

So, good luck, hiopefully something easy!
When I see some of the piles of junk running perfectly that come to me, and this one is all perfectly sorted out telling me to F-off, I'm rather mad.

Sun Aug 03, 2025 3:46 pm

jlrftype7 wrote: What year is your Vanagon?
Need more info to help you-, like, are you losing fuel or spark?
One thing that can cause your symptoms is the braided shield coax cable of the O2 sensor shorting out the inner signal wire on the O2 wire-when this happens, you’ll run really rich and usually die out. The braided coax shield wire is grounded all the time, so if it pierces the inner signal wire, the ECU in turn runs the engine really rich.
You can easily check this with a meter. Take a resistance reading between the inner signal wire and a good ground. Should not have a reading, you ideally read the meter as an open circuit if the shield wire and inner wire aren’t making a connection.
If you get a low resistance reading, the repair is to trim the coax cable at its end away from the inner insulation of the signal wire. It’s usually the last 1/2” or so that pierces the signal wire.
Here’s a picture of the body harness you’d want to check.

Ah of course I should have stated that it is a 1990 vanagon with a 1994 Subaru ej22 engine. I will go check my O2 sensor.

Sun Aug 03, 2025 11:08 pm

Oh, completely different league then.

I would inspect the idle control gate thing at the throttle body, although usually they get stuck open and increase the idle, I don't see it killing the engine but maybe something to look for.

Best is to get the error codes off the ECU....

Mon Aug 04, 2025 5:44 am

ALIKA T3 wrote: I'm following this with great attention as got the same thing happening on my free van, 2.1L Digifant, like the IACV is dead .
Unless I rev it in neutral really hard a few times, it won't idle and die, hard to even rev it sometimes.
I changed just about everything on this damn EFI, it's the first van that I never solved.
New-ish harness, swapped every components :
AFM, distributor, several ECU, several ICM, a few coils, new plugs, wires, cap, rotor, new FPR from Mansi, fuel tank is clean and resealed. New Bosch fuel pump, rebuilt/cleaned injectors. New OXS, new ground strap, clean ECU grounds. Temp2 sender tested good.

The engine had destroyed valve adjuster screws, so I replaced these , added lash caps and rocker shims, and adjusted the valves.

Just unreal. I haven't taken compressions but I don't see how that would do this issue. Engine uses a lot of oil, oil pressure hot at idle is crap, so it's prolly tired but still, it shouldn't do this idle issue.

So, good luck, hiopefully something easy!
When I see some of the piles of junk running perfectly that come to me, and this one is all perfectly sorted out telling me to F-off, I'm rather mad.

Sounds like my previous engine.... :lol: :lol:
Used oil, especially with highway speeds, would eventually leak oil due to ever increasing crankcase pressure even with lots of new seals, but ran great, idle was very smooth.... :roll: :roll: :roll:
And started to show Fire Ring failure happening...but a runner... :)

Mon Aug 04, 2025 5:44 am

ALIKA T3 wrote: Oh, completely different league then.

I would inspect the idle control gate thing at the throttle body, although usually they get stuck open and increase the idle, I don't see it killing the engine but maybe something to look for.

Best is to get the error codes off the ECU.... Yeah, probably NOT related to O2 sensor at all.