T-shaped ICV for m20b25

[Tibboy12]

Hello!

I’m searching for a tested and working t-shaped ICV for an m20b25. Thank you!

[82eye]

Hello!

I’m searching for a tested and working t-shaped ICV for an m20b25. Thank you!

you might have to go new. they are currently available but disappearing fast and getting more expensive every day. i might pick one up myself before they are nla like the eta valves. the cost is holding me back.

[Tibboy12]

Hey,

I’m half tempted to buy one as well.. does no one rebuild these units like other serviceable parts like the ICM and AFM? I’ve been dealing with idling issues and have tracked it down to both the ICV and AFM.

[It's Soda Not Pop]

this guy might rebuild them not sure.

https://www.bavrest.com/index.html

[packratbimmer]

Make sure the check valve for your charcoal canister is functioning - they fail way more often than the ICV. Make sure all vacuum leaks are repaired. I have valves if you need one. Thanks

[jeffnhiscars]

You can try cleaning it w carb cleaner but that's about it for fixes

[Tibboy12]

Hey,

I installed a new genuine check valve for the charcoal canister but still have a bit of a lumpy idle at 500rpms. Waiting on Greg at Bavrest to send back my AFM to see if that fixes the issue if not then I’ll reach back out about an ICV.

[jeffnhiscars]

Many idle issues are related to vacuum leaks. I'd do a smoke test before buying any more parts

[ZeKahr]

OP before throwing expensive parts at the low idle problem, I’d recommend checking your vacuum and compression levels.

I have the same 500 RPM idle (though not so lumpy) as you. I just checked my vacuum with the car fully warm and here’s what I got:
Park (yes, car is auto): 15 in Hg
Reverse (parking brake engaged): 14 in Hg
Drive (parking brake engaged): 13-14 in Hg

Haven’t checked compression yet, planning to have a shop do it (cuz lazy :D)

[packratbimmer]

I had a similar problem back in the day and it was the stock chip in the ECU. When I switched to a SSSquid chip the problem vanished

[ZeKahr]

I had a similar problem back in the day and it was the stock chip in the ECU. When I switched to a SSSquid chip the problem vanished

If an aftermarket chip fixed your issue then it’s probably because the aftermarket chip had more advanced ignition maps. The stock chip uses conservative timing maps to prevent engine damage in the event the engine runs lean. If you pulled out your plugs prior to installing the chip I bet they were sooty

[Tibboy12]

OP before throwing expensive parts at the low idle problem, I’d recommend checking your vacuum and compression levels.

I have the same 500 RPM idle (though not so lumpy) as you. I just checked my vacuum with the car fully warm and here’s what I got:
Park (yes, car is auto): 15 in Hg
Reverse (parking brake engaged): 14 in Hg
Drive (parking brake engaged): 13-14 in Hg

Haven’t checked compression yet, planning to have a shop do it (cuz lazy :D)

Hey! What do those numbers mean?

[Tibboy12]

I ended up purchasing an ICV from a member on here, should get here this week so I’ll report back. In the mean time my buddy just picked up a new smoke machine so I’m going to check for vac leaks on the car. As far as ECU goes, I did let someone else try it on their car when they had a no start issue and my ecu fixed their issue and idled good.

[ZeKahr]

Hey! What do those numbers mean?

According to my Bentley manual, it means the following probable causes:

a. Incorrect ignition timing (retarded)
b. Incorrect valve timing
c. Low compression
d. Throttle valve sticking
e. Leaking intake manifold gasket or fuel injector seals

The Bentley says normal vacuum at idle should be 15-22 in Hg, but 15 is the border of “normal” and “problems”. Something around 17-22 is closer to “normal” vacuum according to the Pittsburgh (from Harbor Freight) vacuum gauge I have

[Tibboy12]

Good to know! I’ll have to refer back to my Bentley and see If I can find that information. Also, my AFM should be coming back from bavrest here soon so I’ll report back on those findings.