Wur...?

[balleta]

Do anyone recognizes this type of WUR?

Sent from my LG-D950 using Tapatalk

[fanaudical]

It sort-of looks like an early Unwired Tools UTCIS (but can't tell for sure). Any markings? Does it work?

[balleta]

Yes it works. Is installed in my 78SC now. It was there when I bought it. No markings of any sort

Sent from my LG-D950 using Tapatalk

[fanaudical]

Huh - OK - Not at all an early UTCIS. I am guessing that is some kind of MANUAL pressure regulator (probably not much more than a needle valve on the other end of that knob on the side).

Assuming the gauge works, do you notice any difference in the fuel pressure when idling right after start-up versus when warmed-up? Are there any other ports/plugs on the other faces?

[balleta]

The gauge is somewhat fogged but works. Really I have not recorded the readings but I see it going up when I manually lift the plate at the fuel distributor to start the car when warm. (I'm having warm starts problems). I checked the UTCIS site and found a kit to correct this condition. Not available at this time but it is easy to replicate.

Sent from my LG-D950 using Tapatalk

[fanaudical]

I'm not sure that I would expect the gauge to change when you lift the plate (unless lifting the plate starts the fuel pump on your car. What year/engine do you have in there?)

Warm start problems are not surprising if that is a manual regulator. The factory WUR changes the active system operating pressure based on temperature and sometimes engine load (depending on WUR model). Who knows what other modifications are in place...

Replacement WUR's are available from various contributors here on the forum.

As an alternative to the UTCIS you may look at FrankenCIS. I think this looks promising as a WUR replacement.

Digital WUR plus? ( FrankenCIS )

[balleta]

I forgot to mention that the plate lifting procedure is switched on so, yes the pump goes on to pressurize the complete system.
The car is stock 78SC with its 3.0
I'm following another thread of the warm start issue and almost everybody points to the fuel accumulator as the cause. I was thinking about an electric valve to shut off the return line after shut the engine off. Then another guy came with that same solution already in his car. I'm waiting for some photos of his car system. Is an easy, not expensive, more modern way to solve a common problem. I will also check your FrankenCIS suggestion

Sent from my LG-D950 using Tapatalk

[Reiver]

CIS Flowtech has wur's of every type in stock/rebuild. He's the only auth Bosch rebuilder in the US for wurs and fuel heads and does them for Bosch.
No affiliation except as a customer, Larry is a good guy to deal with too.

[RarlyL8]

I would simply replace that thing with a new or rebuild WUR of the correct type.
No need to add electric gizmos to any system, just fix what is causing the issue. Warm start problems are typically due to faulty accumulator or check valve. A set of fuel pressure gages will point you in the right direction.
If you do end up needing a WUR we keep them in stock.

[ossiblue]

That is one interesting WUR. If he doesn't have lean cold start issues or overly rich warm running issues, there must be some internal mechanism to adjust the fuel pressure. The body looks to be designed like a heat-sink so, possibly, there is some design that allows for engine heat to change the pressure.

Question to OP, have you ever recorded the pressure on the gauge at cold start and then once the engine is warm and running? I would be interested to know the readings under both conditions as well as the time it took to change.

[balleta]

I took the readings today and found that the gauge goes down only to 38 and not zero. On cold start it rapidly goes up to 90 and stays there also when warm. Rev the engine and it fluctuates a little but mostly maintains a constant press. I found a broken wire at the cold start sensor but really don't think it is the problem since the issue is with warm starts. Will continue...

Sent from my LG-D950 using Tapatalk

[boyt911sc]

Originally Posted by balleta

I took the readings today and found that the gauge goes down only to 38 and not zero. On cold start it rapidly goes up to 90 and stays there also when warm. Rev the engine and it fluctuates a little but mostly maintains a constant press. I found a broken wire at the cold start sensor but really don't think it is the problem since the issue is with warm starts. Will continue...

Sent from my LG-D950 using Tapatalk

balleta,

Not until you replace your WUR and find a good working unit, you will always have this problem. Your main problem is the control fuel pressure compounded by the residual pressure. We don't even know your system fuel pressure at this point. Could you post your residual and system fuel pressures? If you need a good WUR, I could lend you one and try it on your car. Send it back to me when you are done. Do you know IVANUF (Ivan H. from PR)? Keep us posted.

Tony

[balleta]

Tony
You are a gentleman. Not everyday one find this kind of offer. I really appreciate it.
Let me try to take some more pressures and check the fuel acumulator before changing the WUR. I'm trying to remember when this condition started since it was not like that before. And I have changed nothing in the car. It has had that strange manual WUR since I bought it. But I remember the adjustment knob was somewhat out. Now it is all the way in. I will take it off its base to have more access to the knob and play with the adjustment. Will continue...
PD: Don't know Ivanuf but found his email and sent him a note. Saw a post of his project and your help with the FI parts.

Sent from my LG-D950 using Tapatalk

[ivanuf]

Hi Tony. All working perfect!! Thanks

[boyt911sc]

Originally Posted by ivanuf

Hi Tony. All working perfect!! Thanks

Balleta,

Since you have Ivan H's email, contact him and he could give you a lot of good advices and help plus he is local. Ivan got the rebuilt WUR and FD from me. Glad to hear everything is working.

Tony