low to no idle when cold - '90 Westy 2WD

[RBEmerson]

The symptoms: almost no idle after first starting engine, restarts and/or lots of pedal pushing needed. As the engine warms up from just standing, idle comes up to the expected 1K +/- 100 RPM and all is well. No issues with driving.

The onset of the problem was "a couple days ago OK, now it's not". Once warmed up, no problems. This is true with OEM AC on or off, verified with ScanGauge showing _AC signal, as well as "is the condenser fan running".

I have the GW EFI. "Back in the day", I'd ask for their input. Now, at $75/30 minutes, NFW.

I can follow engine temp on the ScanGauge, and it behaves as expected. The temp gauge on the dash also looks normal, and there's no blinking red light.
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[Franklinstower]

First thing I would look at is a dirty ICV, bad o2 sensor or the Temp 2 sensor, ground issue somewhere...

Good luck.
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'89 Westy - EJ25/22 Frank 4.44 5mt
'75 Miami Blue Sunroof FI Standard Bug
YITB

[RBEmerson]

Good starting points all. Can I assume Temp 2 is not what the OBD ScanGauge shows?
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[4Gears4Tires]

I'd start with the Temp2 sensor. I might also start reading/asking questions in the Megasquirt forum, since they're going to be better equipped to diagnose your questions.

This sounds like an issue with the cold start enrichment. Not a tune issue though, since that presumably hasn't changed. Something feeding the tune is broken. Cold start enrichment is based off engine temp, so the temp sensor is the first thing I'd check.
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'87 Syncro Ferric Oxyhydroxide Superleggera Edition
'85 Westy Sciuridae Domus Edition

[RBEmerson]

The Temp 2 sensor is looking more and more like the most likely villain. The O2 sensor is behaving itself (ScanGauge data), and I replaced the ICV recently (unrelated issue).

After my last go-around with GW over their EFI (gee, wish I could pull down $150/hr for automotive phone sex...), I thought seriously about yanking the EFI for a Megasquirt system from MansiSpeed. And hit a deal-breaker: no OBD support. The GW EFI stayed, but I assume it's effectively unsupported. (can you tell I'm less than head over heels in love with GW?)
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[RBEmerson]

Any words of wisdom on swapping the Temp II sensor?

It appears to be "get a new sensor, get a new O-Ring, put a bucket under the thermostat housing, do a 'hot swap', dump the spilled antifreeze back in the expansion tank".
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[AlfromNH]

[RBEmerson]

D***, d***, d***!! >:-(

I switched to the Van Cafe thermostat housing. They use a threaded temp sensor. And they're not answering their phones. Hades will probably freeze over before I find out "no NAPA, exclusive with us" for sourcing the sensor locally.

Has anyone successfully come up with a FLAPS-sourced Temp 2 (and Temp 1) sensor?
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[Altoona]

It is just the 1.9/syncro sensor.

[Altoona]

Also, to test the sensor, just plug a good one in and try it when cold, no need to swap it out yet.

[RBEmerson]

I just looked on Bus Depot (close to me) and there are two contenders

1) P/N 0280130026 - grey connector
2) P/N 025906041MY - Blue connector

The good news is VC used a sensor that accepts the old push-in sensor's connector

So, do I want what's behind door #1 or door #2 or Carol Merrill? ;D
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[RBEmerson]

[Altoona]

https://www.busdepot.com/0280130026

This should be what you want.

I see they have two different ones that are the same with different part numbers. I would go with the bosch sensor.

[RBEmerson]

Sounds like a winner to me! Thanks!
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[RBEmerson]

The rest of the story...

Confronted with a non-standard (for the 2.1L Westy motor) Temp 2 sensor, and a distinct need to get our Westy running, I waved around a can of CRC's contact cleaner, and played with the plug and sensor.

To my surprise, the sensor read 2K ohms, which is right for an ambient temp in the 70's. I tried cleaning the contacts, plugged the cable back in and... Normal idle. Since then, the engine fires and idles as it should, with or without the AC on.

Bottom line, the sensor is working as it should. The problem was probably only a dirty connector. I will NTL keep a spare of the correct sensor on hand "just in case".
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.