Jump to content
Ultimate Subaru Message Board

Troubleshooting conversion


Recommended Posts

Hey Volks and Folks:

 

First time poster here. Though I'm not new to the SubaruVanagon thing. I completed my conversion 6 years ago and this is the first trouble I've had. As a matter of fact, I haven't posted to the SubaruVanagon Yahoo Group in a while. The conversions are more refined now a days than mine so I don't have much to add. And, my conversion has been so reliable I haven't had to post much:-)). It's an 84 Westy Wolfsburg that I got for a song with a busted tranny (how's that for reversed). I didn't even bother with the wasserleaker. Went straight for the conversion.

 

BUT, I'm having trouble now. I've got a miss at idle and under load that I can't seem to diagnose. I've cross posted to the Yahoo group in the hopes that someone will be able to help me.

 

Here's the summary:

 

Symptom: Miss at any engine speed below about 3500 rpm. Lopes while idling cold or hot. Can't isolate it to a cylinder with either a plug wire or injector connection. Will even die at first start while idling. I've replace the coil pack and plug wires and regapped the plugs and replaced the fuel filter.

 

When that didn't fix it I cobbled together a fuel pressure gauge. I don't have much faith in the accuracy of the gauge but it seems to be in the ball park. Sustained pressures of 38 psi. Pressure goes up to about 42 psi with the vacuum connection to the control pressure regulator removed and when it almost dies while idling.

 

A vacuum test showed a narrow vibration at idle but within spec that disappears as throttle is applied. If I pinch the fuel return line closed it jumps instantly to over 100 psi, so I don't suspect the fuel pump. No obvious vacuum leaks. I sprayed carb cleaner around the intake manifold with no change.

 

In test mode I get the following codes:

 

12 Starter switch remains on (expected)

14 fuel injector

15 fuel injector

17 fuel injector

23 air flow sensor (could this be caused by the miss?)

33 Speed sensor (tried 3 different ones and can't find one it likes)

35 purge control solenoid (expected with the above)

 

I'd appreciate any help. It's been warm here so I REALLY need to get my bus fixed. Time to Camp and Sail!

 

Should I cross post this to another discussion? If so, how?

 

Thanks.

 

Shawn

84/90 Westy/Soob

Jackson, MS

Link to comment
Share on other sites

That must be the black connector readout. Thats every code since the battery was disconnected. Not a good indicator usually.

 

If you have a CEL plug the green's together and report findings.

 

I suspect the air flow meter. When they are flaking out they cause a lack of idle. What kind of air filter setup are you using?

Link to comment
Share on other sites

Your black connectors aren't plugged in?

 

Either way those are all the codes since the battery was disconnected, not necessarily current problems. I would disconnect the battery and drive it for 3-5 minutes and see what "new" ones come up.

Link to comment
Share on other sites

Shawn:

 

I don't have a CEL. (No smog requirements here). I use the LED on the ECU to check the codes. Is this giving me test mode codes or read mode codes?

 

Thanks.

 

Update. Cleaned the throttle body (dirty) and tried to adjust the idle with the IAC. Still missing. At warm idle the o2 sensor was reading .7-.82V .

 

Also sprayed carb cleaner around the intake/head interface. No change in idle. Varified fuel pressure readings (o.k.).

Link to comment
Share on other sites

More info. Disconnected the battery overnite. Checked the engine ground, cleaned up the throttle body, checked again for vacuum leaks. Then drove around the block for a few minutes. Still have a miss at idle and under load. I even set up the BC/BF scan tool to read from the Subaru Select Monitor. Nothing really out of whack except for a wildly fluctuating AFM voltage. Checked the codes:

 

16: I disconnected it momentarily to check for a miss.

35: Purge Control; I've always gotten that one.

 

So what's the next move here? AFM or am I looking at a compression test?

 

Thanks for any suggestions.

Link to comment
Share on other sites

  • 2 weeks later...

:banghead:

 

Another update and Uh-Oh.

 

I replaced the air flow sensor with one from the junkyard. Same thing. Miss throughout driving range.

 

Disconnected the battery cable overnite.

 

Added some Iso-heat water remover. And drove about 15 miles. Seems better but still not good. Still misses at idle and has a miss under load below 3000 rpm.

 

On another note. I've been reading alot. Too late. I've commited a cardinal sin. I fussed with the throttle stop screw and used a carb cleaner on the throttle body. Of course the idle is too high (1500+). I've also tried to reset the throttle position sensor.

 

AND to top it off, my mother hit a deer with my other vehicle so I need my bus back ASAP.

 

Junk yards here are asking $100 for a throttle body. But I don't think that's the source of my problems. I can live with a high idle until I can find one at a reasonable price. I am worried about the miss.

 

Any further suggestions?

Link to comment
Share on other sites

  • 4 months later...
  • 2 years later...

I just stumbled into my old post and thought I had updated the thread. Anyway, after throwing parts at it for almost a year I finally figured it out. The hydraulic tensioner bolts came loose. Every time I hit the throttle the timing on one bank would get out of time. Since there was only one cam sensor the computer could not adjust. So take warning. The tensioner bolt torque spec (20lbs IIRC) is not enough. AND USE LOCTITE! I'm blaming it on not replacing the timing belt idlers. But who knows.

Good Luck.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...