Warm-up Regulator 3.0 or 2.7 please help

1979911sc · 1979911sc's Garage

I am looking at buying a rebuilt wur for my 79 sc usa model. After taking it off the car i looked up the part number 0438140 009 and it shows to be for a 73-75 2.7 or 2.7s. I am the second owner and part is believed to be original for the 3.0. I just wanted to see which one I really needed? (There is no cat or smog equipment on the car) thanks Troy

wowzer911 · 02-07-2009, 08:47 AM

Take another look at your WUR, your part number posted in not correct.
Ever consider a digital WUR?
Check this link for digital WUR, scroll down and you'll also see correct WUR part numbers for different 911 models and years.
http://unwiredtools.com/utcis.asp

1979911sc · 1979911sc's Garage

I will consider the digital warmup reg but to save money I was hoping to get a rebuilt one. The part number I used is the bosch part# 0438140 009. According to specialtauto.com it shows up as a 2.7- 73-75 not the 3.0?

kodioneill · kodioneill's Garage

what is wrong with your current wur. is your engine running poorly?

wowzer911 · 02-07-2009, 09:19 AM

also shows up as equivolent to porsche part 91160610901 (1974-77) on some sites.
78-79 WUR shows up as Bosch 0438140045/0438140089 on some sites.
I can see where this can be confusing.

1979911sc · 1979911sc's Garage

I was told by my mechanic that it is the warmup reg. The car runs terrible until it is warmed up. It has an oscilating idle, runs very rich and will die if left unattended. When it is warmed up after a couple of miles or so it runs great. I just need to know if the warm-up reg I have the 0438140 009 was ever used on a 79 or if anyone else has one on theirs or if it will work?

e p slick · e p slick's Garage

Rebuild it yourself. Very simple. Imagine has kit.
Cleanliness, cleanliness, cleanliness.

EPS

wowzer911 · 02-07-2009, 09:44 AM

The point he's making is that he's not sure he even has the correct WUR to begin with.
The part number seems to correspond to a 2.7L and not his 3.0L.

wowzer911 · 02-07-2009, 10:04 AM

Looks like others have used differing WURs with sucess.
WUR Question

kodioneill · kodioneill's Garage

Quote:

Originally Posted by 1979911sc

I was told by my mechanic that it is the warmup reg. The car runs terrible until it is warmed up. It has an oscilating idle, runs very rich and will die if left unattended. When it is warmed up after a couple of miles or so it runs great. I just need to know if the warm-up reg I have the 0438140 009 was ever used on a 79 or if anyone else has one on theirs or if it will work?

make sure there is power to it after the engine starts. also you should check pressures. if there is power then check the resistance of the element. if it is open then the coil is bad.

ossiblue · 02-07-2009, 10:21 AM

First, it is quite possible that you have a different WUR than specified but, as mentioned above, that does not mean it is your problem.

Your symptoms describe an overly rich cold-start mixture which can be simply from a misadjusted WUR, regardless of the part#. How much do you trust your mechanic's opinion? How much experience does he have with CIS? Did he do pressure checks, and electrical checks on the system?

You may be able to save yourself considerable frustration in tracking down or paying for a WUR that you don't really need. If you can post the answers to the questions, above, the people here can help you more readily.

boyt911sc · boyt911sc's Garage

Troy,

The WUR (-009) was calibrated for '75 and WUR (-045 & -069) were calibrated for early SC's ('78 &'79). All these WUR's will work on your car provided they deliver the correct control pressures (range).

Ask your mechanic to check the cold control pressure, power supply to WUR, and how much resistance (heater). Don't replace WUR unless confirm defective. At this time of the year, you will need about 1.0 - 1.5 bar or less for cold control pressure and your resistance should be around 24 ohms (+/-).

You could easily perform these tests if you have a CIS fuell gauge and a multi-tester. Keep us posted.

Tony

1979911sc · 1979911sc's Garage

First of all let me thank everyone for the great advice and info! I had managed to drive the car daily for over a year in vegas. Now that I moved back by omaha it has become my winter project/summer driver). Last time I had it checked out we believed the heating element of the regulator to be at fault. I had all the fuel pressures checked at various temps (don't have the #s in front of me b/c car is currently in storage) There is power to the wur. I was wondering if anyone else is using the UTCIS digital warm-up regulalor and if there are major benefits to be had. Otherwise I will get a rebuilt one and install it. Then i will get it to my tech to have the fuel pressures checked and hope I have not wasted any money. Thanks Troy

1979911sc · 1979911sc's Garage

I will also get an ohm meter and try to double check the resistance first. Do I need to dismantle it?

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by 1979911sc

I will also get an ohm meter and try to double check the resistance first. Do I need to dismantle it?

Troy,

NO!!!!. All you need to do is disconnect the plug to the WUR. Then use the ohm meter to measure the resistance of the heater inside the WUR. Typically, the -045 WUR's have about 24 - 25 ohms (new). However, as they aged and gets worm out, the resistance tends to deteriorates over time.

If you're planning to buy a used WUR, make sure that it has a good resistance (heater). Or obtain it from a reputable rebuilder. Keep us posted.

Tony

4sd911 · 02-08-2009, 09:16 PM

I may be out in left field here but, shouldn't the '79 WUR be of the vacuum type? The '73-'74 are not vacuum type. I think the vacuum type starts with the '75. Is the one you have vacuum or non.

T77911S · 02-09-2009, 06:08 AM

the 78-79 needs the WUR with the vacuum port. the early ones did not have this. the 77 should work too, although the vac port is on top fot eh 77 and the side for the 78-9

1979911sc · 1979911sc's Garage

The regulator has a vacuum port on the top of regulator. Not on the side like I have seen in pics of the 78-79. I checked the resistance with an ohm meter and it read 30.8. So I am not sure whether to rebuild or have it and the fuel pressure adjusted?

ossiblue · 04:37 PM

Quote:

Originally Posted by 1979911sc

The regulator has a vacuum port on the top of regulator. Not on the side like I have seen in pics of the 78-79. I checked the resistance with an ohm meter and it read 30.8. So I am not sure whether to rebuild or have it and the fuel pressure adjusted?

First things first (and cheapest)--check the pressure of the fuel system, especially the cold, regulated pressure (with the heating element disconnected). Too low of pressure will produce your symptoms, and the WUR can be adjusted if this proves to be the case. Your "incorrect" WUR should be fine for your car if it is working properly, though it was not the one supplied for the engine.