Solenoid cold start valve

[mauro12]

Hi guys, I’m trying to solve a problem of fuel consumption in my car. I’m sure depends on the csv and I’m almost sure that my solenoid is not working . When I disconnect the valve and I turn on the ignition ( without starting the engine) I see fuel coming out but I guess this fuel is not stopped due to the solenoid failure and for this reason I have rich mixture . Can you give me some advice? Thank you

[mnahon]

You probably need to lap the CSV valve. There are a few threads on this topic. Do a search using the search function using keywords 'leaking CSV' and you should find them/

[kampala]

Mauro,

Read this section of the Tech Manual :  https://www.sl113.org/wiki/Engine/ColdStartValve

There is a lot of information in the Tech Manual about CSV.

If your electric wire is disconnected ( I think this is what you mean) and I assume you see fuel when you remove the small access bolt on the side?  If that's the case, see the tech manual you may need to clean the valve seat or give it a lapping as mentioned.   

If you are seeing fuel at the electric connection area on the solenoid, this is usually solved by replacing the small seal that you will find when you remove the solenoid from the valve body.  A very common problem.

[mauro12]

Hi, thank you all for this advices . According to your experience what could be the cause of a fuel consumption of 9mpg? I’m pretty sure I have a leaking cold start valve but if I’m wrong what do you suggest me to look? Distributor and plugs are ok ( I have electronic ignition) no problem at all for cold start or hot start. The problem is only this huge fuel consumption .

[mrfatboy]

Leaky fuel injectors?  Take them out and test them.

[mauro12]

I cleaned ultrasonically and now they are ok, before the cleaning they had terrible spray pattern. The fuel economy improved a bit but nothing more . In your opinion a leaking csv can cause a fuel consumption around 9mpg?

[mrfatboy]

It definitely will contribute to it.  Have you looked at your injection pump? Is it running rich?

[mauro12]

Is running rich overall .yes.

[mrfatboy]

I would suggest fix your CSV first then check   your FIP mixture again.  Use process of elimination 👍

[Benz Dr.]

If your warm up regulator isn't shutting off completely, and by this I mean even a small amount, you can and will end up with a rich mixture.  It's key to getting everything else to work. Everything is important so check everything for proper function.

[mauro12]

To repair the warm up regulator you have to change the thermostat right?

[mrfatboy]

Have you removed the air filter on the fuel injection pump to see if it stops sucking air when the car is warm?  That should tell you if it's working properly.

When the car is cold you should hear a loud air sucking noise and suction which slowly gets quieter and less suction as the car warms.

[mauro12]

It can be possible that the system is not working at all? I feel no air being sucked at all. I was feeling some mo the ago but I think something is wrong now. Maybe the thermostat

[mrfatboy]

If the car is cold and you are getting no air suction I would think the air slide valve is stuck closed.

Cold car has suction through FIP Air filter that slowly diminishes as car warms.

Totally warm car should have no suction through the FIP Air filter.

[mauro12]

The best thing to do I guess is to disassemble the wrd and inspect the thermostat and the air filter. The car starts much better when warm rather than cold. When cold I have to push gas a little and after it starts.

[mrfatboy]

Before disassembling the WRD just take off the air filter on the FIP and test the air suction as stated above

[mauro12]

How I remove the air filter?

[Cees Klumper]

You don't actually need to remove the air filter. What works very well, is to hold a piece of plastic or rubber hose, doesn't have to be that big in diameter, close to the air filter inlet, and hold the other side to your ear. You will be able to hear air noise very well as the car warms up from a cold start and, if the thermostat/WRD is doing its job, you will hear it shutting off slowly.
Otherwise, to take the filter off requires a very skinny open wrench. Not sure about the size but it's not small. You can replace the filter with a new one, but this likely is not your problem.
Once you know what the noise sounds like of the air rushing through on cold starts, you don't really need a piece of hose to hear it, you will recognize it just being close enough to the engine with the hood open.

[wwheeler]

I believe the size is 22mm. As Cees says, it needs to be a skinny (thin) open end wrench. The flats on the air filter are quite narrow and a standard width won't fit. You can buy them or just buy a standard 21mm open end wrench and grind the face off to fit. I take the air filter off from time to time and mostly for access to other parts around it. Handy wrench to have for you collection.

[mrfatboy]

So close   I just checked because my pump is off my car.  It's a 22mm. 

[wwheeler]

So close   I just checked because my pump is off my car.  It's a 22mm.

That is what you get when you go off of memory or what is left of it. Close only counts in horseshoes and hand grenades!

Thanks for catching. I edited my post.

[ja17]

On the early cars the filter is a 19mm on the later it is a 22mm. (skinny wrench required) These filters can get clogged. When this happens the WRD works fine but the mixture is always rich during warm up. In addition fast cold idle is non existent.