Subaru idle problem (EJ20 in a T25)
Posted: 11 Dec 2017, 17:29
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
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