Subaru idle problem (EJ20 in a T25)

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Hoopy_Frood
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Subaru idle problem (EJ20 in a T25)

Post by Hoopy_Frood »

Hi,
Apologies for the long, probably rambling post.
I have a my2000 EJ20 (MAP configuration) in a 1984 VW T25. Conversion parts were from RJES and engine and loom were from Nick Tune.

I've had some idle issues for a while - have tried previous suggestions to fix them but it's gotten worse lately and my engine management light now comes on intermittently. The fault code it shows is 24 - ISC solenoid-related.

The symptoms used to be:
1. High idle at startup (not unusual)
2. Idle stays very high until the engine is hot then it settled down
3. After setting off, the throttle doesn't back off when i lift my foot off the pedal (very slow for the revs to drop if at all)
4. Pushing the clutch pedal down increases the revs (again, it stopped doing this when up to temp)
Note that none of the above caused the engine light to come on and when it was at temperature everything was ok and the van drove fine.

I tried replacing the ISC valve and cleaning out the inlet, but it didn't make any difference so I cleaned up the original part and put that back in.

I then tried replacing the throttle position sensor with an old one I had, but no difference there either so popped the old one back in.

Since then, it's gotten worse.

The symptoms now are:
1. Engine revs surge at startup and then drop till its starts to sound rough (like only 3 cylinders) and then the engine light comes on.
2. Engine hunts a bit - revs go up until the engine light goes out then drops till it comes back on again (rinse and repeat)
3. Idle generally sounds much rougher than it used to.
4. Coming on or off the power is very "juddery", much more than I've noticed before.
5. The throttle still doesn't back off when i lift my foot off the pedal.

I'm at the limit of my expertise here and my google-fu clearly isn't as strong I had hoped to be able to find a fix.

Next on the list of parts to investigate is the MAP sensor - new one ordered and I'll see if it improves anything.

In the meantime, am I missing something obvious?
Have you guys found anything like this, if so how did you fix it?


Thanks
Iain
1984 T25 Poptop EJ20 conversion

Goldfeesh
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Re: Subaru idle problem (EJ20 in a T25)

Post by Goldfeesh »

I had something similar in the beetle with an ej20. Can't be sure what fixed it because I did 3 things at once.

1. Iacv (idle air control valve) swapped out for a known good replacement.
2. Speed sensor installed.
3. Put the lambda sensor in.

Settled down after that.

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torsen
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Re: Subaru idle problem (EJ20 in a T25)

Post by torsen »

I feel your pain, I had exactly the same issue with my EJ25D install and after trying several 'fixes', going through a process of elimination and trawling through the internet I found the excellent resources of the 'subaruvanagon' Yahoo Group.

Using this I finally nailed it down to the neutral position switch circuit.

My ECU needs to see a signal coming from the NPS that emulates what the ECU normally sees when connected to a Subaru gearbox (mines an auto ECU). In the real world this is a fluctuating signal that corresponds to the shifter position. In my case initially I just had the NPS wired to ground and therefore constantly on, this was my problem and disconnecting it didn't help either.

Anyway, I can't share the file with the solution here but if you sign up to the Yahoo group you will see it in the files section along with a lot of other useful info. All of the parts required were obtained from ebay and fitting was easy with a little 'tuning'. I now have no running issues or code 24 fault code. Not saying that this is your issue as your install is different to mine but worth a try.

Any problems PM me, good luck.

https://groups.yahoo.com/neo/groups/subaruvanagon/info

multisi
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Re: Subaru idle problem (EJ20 in a T25)

Post by multisi »

Torsen was there a fault code showing up when you had the problem regarding NPS.
1992 red lle 2.2 subaru 1990 rhd caravelle 2.2 subaru 1986 california import vanagon

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torsen
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Re: Subaru idle problem (EJ20 in a T25)

Post by torsen »

multisi wrote:Torsen was there a fault code showing up when you had the problem regarding NPS.

Yes fault code 24 idle valve

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