[WUR] heat element testing

[Platiporsch]

I checked my warmup regulator with a ohm meter and it only shows 9.4 ohms,the Bentley manual calls for 30 to 40 ohms. I have two old warmup regulators laying around, i checked them and they are both 35 ohms however they are the wrong year for my car, I have cold start problems and im waiting for my CIS pressure tester to arrive. meantime how would the low ohm reading affect my cold start problem.

[Funracer]

bump

[Travis Neff]

I believe that the lower the ohm rating the slower the bimetallic strip heats up, which would affect your warm up time.

[boyt911sc]

You just resurrected a 17-year old post. Must be the effect of the pandemic.

Tony

[AndrewCologne]

I guess Funracer just wanted to pump up an issue where he refers to as well.

[AndrewCologne]

@ FUnracer

AFAIK your engine is a lambda based one so your WUR comes with a two level resistance heating, means one at 10 Ohms and another at about 23 Ohms (or 30, not sure).
The actual resistance depends on the actual temperature and the lever which affects the resistance can be set in the picture below.

[mysocal911]

Originally Posted by Travis Neff

I believe that the lower the ohm rating the slower the bimetallic strip heats up, which would affect your warm up time.

It's just the opposite.

[Funracer]

Originally Posted by boyt911sc

You just resurrected a 17-year old post. Must be the effect of the pandemic.

Tony

Haha I know. That might be a record. But I thought it was a good question that went undiscussed.

[Funracer]

To the point though, my car is at 2.6bar CCP with WUR unplugged and stays there until plugged in then goes to 3.7bar within about 3 seconds. My car cold starts instantly runs perfectly for 2-3 seconds then idle drops to 500 RPM and surges up and down 3-4 times until everything warms up (about 4-5 minutes) then it runs and starts perfectly the rest of the day.

My WUR measures 9 ohms when warm and 25.6 when chilled with ice bags.

Thanks

So I guess my question is on cold start should it go from 2.6 to 3.7 so quickly?

[boyt911sc]

Originally Posted by Funracer

To the point though, my car is at 2.6bar CCP with WUR unplugged and stays there until plugged in then goes to 3.7bar within about 3 seconds. My car cold starts instantly runs perfectly for 2-3 seconds then idle drops to 500 RPM and surges up and down 3-4 times until everything warms up (about 4-5 minutes) then it runs and starts perfectly the rest of the day.

My WUR measures 9 ohms when warm and 25.6 when chilled with ice bags.

Thanks

So I guess my question is on cold start should it go from 2.6 to 3.7 so quickly?

Funracer,

Your engine will always experience erratic cold idle. The problem is that the transition period or time from CCP to WCP is too short (3 sec.). You will need a properly calibrated WUR-090 to correct the problem. What is the heater resistance value (Ohms) of the WUR when engine is cold?

The answer to your question is NO. Keep us posted.

Tony

[AndrewCologne]

Originally Posted by Funracer

My WUR measures 9 ohms when warm and 25.6 when chilled with ice bags.
So I guess my question is on cold start should it go from 2.6 to 3.7 so quickly?

The ohm/temp value relations seem ok, so its like Tony said, ... your WUR should be recalibrated

Originally Posted by Tony

What is the heater resistance value (Ohms) of the WUR when engine is cold?

I read 25.6 ohms from his line above

[boyt911sc]

Funracer,

Let me be more specific. What is the heater resistance value (Ohms) of the WUR at room temperature (68°~70°F) or ambient temperature? Thanks.

Tony

[Funracer]

Originally Posted by boyt911sc

Funracer,

Let me be more specific. What is the heater resistance value (Ohms) of the WUR at room temperature (68°~70°F) or ambient temperature? Thanks.

Tony

I live in FL. It was 96 today. It won’t be 68-70 til November.

However I did take that reading in May when it was 85F. It was 9 ohms.

Also took it yesterday when it was 92 in the morning. I think it was 8.9 0r 9.

[boyt911sc]

Originally Posted by Funracer

I live in FL. It was 96 today. It won’t be 68-70 til November.

However I did take that reading in May when it was 85F. It was 9 ohms.

Also took it yesterday when it was 92 in the morning. I think it was 8.9 0r 9.

Do you have WUR-090? When you get a chance, read the posts of “Mike in FL” and “JSZ” regarding their WUR-090’s that were newly rebuilt but out of calibration. Since you live in sunny FLORIDA your cold idle could be tolerable but not if you live where you get frost and snow.

As you have observed, the WUR gets to warm state or condition quickly while the motor is still warming up.

Tony