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Discussion Starter · #1 ·
Having troubles with enrichment? Hey try this out, it may or may not work for you...
I was browsing through my Bosch fuel injection book and stumbled upon a section that talked about the different styles of warm up regulators. Some of the regulators have an atmospheric compensation port; this port can be used to convert your CIS/lambda or Basic warm up to act as a load sensitive enrichment device. So I popped the little black cap off the port and ran a vacuum hose from the port to intake manifold vacuum. This jacks control pressure up to 70 PSI at idle, when under WOT it drops to 50 PSI. Re-calibrate the fuel mixture so it runs at 50% dwell with the 70 PSI control pressure. The next time the vacuum drops it will drive the warm up to reduce control pressure in synchronization with the engine load! While I was driving I was monitoring the O2 and at WOT it responded with a perfect slightly rich .70V-.75V under a heavy load.
I’m ditching the throttle-activated enrichment; it sucks compared to this!
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (gearhead455)

So you're saying your warm-up regulator has this port available? My understanding was that only "high end" model cars had this type of regulator, like the Audi 5000 Turbo (which does have this). I quickly scanned mine for this port last month but wasn't appearent to me it existed...where abouts is this cap you speak of? Is it possible you have an Audi 5000 Turbo or Mercedes warm up regulator?
Jason

[Modified by ONLY 8V, 7:00 PM 4-11-2002]


[Modified by ONLY 8V, 7:01 PM 4-11-2002]
 

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Discussion Starter · #3 ·
Re: Enrichment problems? CIS K-Jet guys: Try this mod! (ONLY 8V)

Some CIS warm up regulators have this port for "high altitude compensation" according to the bently. I got a reman unit from "The parts place" for $60 and it had this port on it ..... so did the one I turned in I got off of a junked 85 Jetta GL. I'll take a picture of it friday.


[Modified by gearhead455, 3:08 AM 4-12-2002]
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (gearhead455)

Okay, that makes sence...didn't realise they offer them from the factory on VWs...was this standard on a certain year or is it for high altitude markets (like Denver)?
Jason
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (ONLY 8V)

I don't think he is talking about the side ports from the Audi Unit (boost sesitive) but the top port next to the electronic connector on the top of the WUR...
I wanna see pics of how this is set up..
James
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (ONLY 8V)

BTW which bentley did you read that in?? Can you specify page number too?
Thanks!
Jason
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (ONLY 8V)

Actually the side port on the Audi version isn't really for boost....one is for altitude compinsation (reads atmosphereic pressure) and the top reads full load enrichment (vaccum)...this is just a little more advanced than the single unit, but neither is a "boost" reader...the full load acts as this. The one gear is refering too is actually a full load enrichment unit or a combo FLE and altitude compensation. Got this info from the Bosch Fuel Injection and Engine Management book and the Bosch CIS Technical Book (Bosch yellow book).
Jason
 

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Discussion Starter · #8 ·
Re: Enrichment problems? CIS K-Jet guys: Try this mod! (ONLY 8V)

I don't have the book with me now ( I left it with the car at my other garage). It's in the blue Bosch book with the hot wire MAF on the cover. Inside there is a picture of all of the different types of pressure regulators side-by-side. If you ever see a warm up with a black cap on the front next to the electrical connector, pull it off, you will see a port.
I found a picture on the net that looks like the regulator I have, except mine has a plastic cap covering that port sticking out next to the connector.
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (gearhead455)

Can you provide the part number for the rebuilt WUR you bought...can you provide both the Bosch Part number and the VW/Audi part number as well? Also, where abouts is this "Parts Place" where you bought yours?
Thanks...Jason
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (gearhead455)

where in the engine compartment is locate the warmupregulator?
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (gearhead455)

Gearhead....couple more ?s....what were your control pressure reading prior to making this change. Also, at WOT what were the O2 senor readings prior to making this change (i.e. with the WOT switch enrichment). Basically just wanting to see if this actually make for improvment for the 83-84 GTI K-Lamda with the WOT enrichment switch. If you didn't do these tests prior to connecting the WUR to vacum, would I be asking for to much to have you run thru the same test both with and without(but with the WOT switch) the vacum line to the WUR....proper comparisions would need to be done on the same day in the same location/altitude.
Thanks!
Jason
PS: could you give me a brief run down of the motor that you're running this on?

[Modified by ONLY 8V, 10:58 PM 4-11-2002]


[Modified by ONLY 8V, 10:59 PM 4-11-2002]
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (gearhead455)

Was just thinking of a third test....vacium line connected to the WUR AND the Full Throttle enrichment swtich hooked up....this should give even more fuel, one would think....not that it would necessarly be needed for most apps, but it would be nice to see what O2 sensor numbers come up in this situation for those really high HP motors....like the ones you and I are most interested in

Jason
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (ONLY 8V)

Very interesting info, Gearhead. I've long wondered if that would work. I recall standing in front of my motor , wondering "if the environment is pushing into the WUR and properly leaning it for altitude, why wouldn't a vacuum pulling in the opposite direction of the atmosphere, fatten things up? "
I just kept forgetting to investigate further. Come to think of it, I should have just thrown my vacuum pump on the WUR and see what happened on the A/F meter. Anyway...
ONLY8V, both of my Rabbit GTI's have had this type of WUR(don't have the pn in front of me), so I don't think we're dealing with anything exotic or rare.
I'm headed to the dyno on the 28th. We'll have a wbO2 sensor to track fueling, so ........hmmmm. I could do some tests to see what's happening to quantify stock enrichment, the adj trim pot fuel inrichment I have hooked up on my 83 GTI, and the added vacuum line fuel enrichment.
 

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Discussion Starter · #14 ·
Re: Enrichment problems? CIS K-Jet guys: Try this mod! (ONLY 8V)

Gearhead....couple more ?s....what were your control pressure reading prior to making this change. Also, at WOT what were the O2 senor readings prior to making this change (i.e. with the WOT switch enrichment). Basically just wanting to see if this actually make for improvment for the 83-84 GTI K-Lamda with the WOT enrichment switch. If you didn't do these tests prior to connecting the WUR to vacum, would I be asking for to much to have you run thru the same test both with and without(but with the WOT switch) the vacum line to the WUR....proper comparisions would need to be done on the same day in the same location/altitude.
Thanks!
Jason
PS: could you give me a brief run down of the motor that you're running this on?
My current engine mods are in my sig (no MSD retard yet)
Fuel pressures on the warm up where 50PSI at idle before the mod and 70PSI after the mod.
I received the warm up from a place locally called “Parts place”. Here is the web site : http://www.partsplaceforallvws.com/
I will try to look at the WUR today and find the part #
I still need to do more testing, I still need to know the affects of this upon cold start up (should be OK)
I will try both enrichment methods at the same time and see what happens…
I would also like to try to put is a manual boost control valve inline with the vacuum source. Then tweak the fuel ratios and WUR enrichment for a fine adjustment!

Well my big problem I had with the throttle activated system was inconsistency. If I was at 3/4 throttle under a load, the engine seemed to lean out before I hit the switch. Sometimes the when I was at full throttle under a heavy load it could only muster up .45V on the O2. Sometimes when I was at a lighter load at WOT the O2 would read too rich well into the .85V range. Now when I am into the throttle medium it NEVER reads under .55V-.60V. Before the O2 used to swing all over the place. WOT is a rock solid .70V - .75V under any load. Also I noticed that the car seems to idle smoother after a real hard WOT acceleration, I think this is because when I decelerate from WOT the intake manifold vacuum increases to 22 inches of vacuum and drives the warm up lean. (cutting off fuel on deceleration)
It occurred to me that the WOT 60% duty cycle enrichment is kinda dumb. Sure, I am at WOT but how much fuel do I need really for the load I have? That’s why I think this system of using the WUR is better.
Now you all realize that this has to be validated on a dyno so this is all in the experimental stage now. The results on the O2 sensor and my "a$$ accelerometer reading" are encouraging.



[Modified by gearhead455, 5:56 PM 4-12-2002]
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (gearhead455)

Boy oh boy, you guys like confusing my train of thought on this topic. I'm currently running the euro/CIS basic injection on my car and my trip to the dyno proved that the car was running lean up top. I tried hooking up an Audi 5K WUR to the car but it actually ran worse, way worse. I was a little confused as to where to hook the vacuum line at first. The first time I hooked it to the port on the throttle body and when I fired it up it smoked like crazy, running super rich. After taking it for a drive, I then moved the vacuum hose to a connection on the front of the intake, where I have my knock sensor vacuum hose connected. It idled much better but after another drive, the feeling at WOT was still worse than with the CIS basic WUR connected.
So, I guess I'm still wondering where exactly do you run the vacuum hose to on the intake?

Thanks!
 

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Discussion Starter · #16 ·
Re: Enrichment problems? CIS K-Jet guys: Try this mod! (davela72)

quote:[HR][/HR]Boy oh boy, you guys like confusing my train of thought on this topic. I'm currently running the euro/CIS basic injection on my car and my trip to the dyno proved that the car was running lean up top. I tried hooking up an Audi 5K WUR to the car but it actually ran worse, way worse. I was a little confused as to where to hook the vacuum line at first. The first time I hooked it to the port on the throttle body and when I fired it up it smoked like crazy, running super rich. After taking it for a drive, I then moved the vacuum hose to a connection on the front of the intake, where I have my knock sensor vacuum hose connected. It idled much better but after another drive, the feeling at WOT was still worse than with the CIS basic WUR connected.
So, I guess I'm still wondering where exactly do you run the vacuum hose to on the intake?

Thanks![HR][/HR]​
Did the CIS basic have this port like in the picture above? Audi 5000 WUR's have 2 ports, one for barometric compensation and the other for boost. If you are using the boost port, I don't think it will work with vacuum.

Otherwise you have everything hooked up right if you are using the port in the picture, the warm up connected to intake manifold vacuum like it's supposed to. But you missed one VERY important aspect of this mod. With the engine at idle, you MUST reset the fuel mixture to be compatible with the new WUR base (at idle) pressure of 70PSI instead of 50PSI. If you don't your car will respond like you described.

[Modified by gearhead455, 5:51 PM 4-12-2002]


[Modified by gearhead455, 5:57 PM 4-12-2002]
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (gearhead455)

gearhead, I was using the smaller, boost, outlet on the WUR for the vacuum. I just assumed that would be the one to use, guess I was wrong. Now, for a dumb question, how in the world do you get a vacuum hose over that big port on the WUR?
It looks like I might have to give it another try. I could just put the WUR that was on the car back on, i.e., '84 GTi w/ the atmospheric port on it. I guess I could then try to run a vacuum hose from that port to the intake.
Please let me know how you squeezed a hose over that port though.
Thanks!
 

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Discussion Starter · #18 ·
Re: Enrichment problems? CIS K-Jet guys: Try this mod! (davela72)

I had to use a fairly large diameter vacuum hose i got from the hardware store.
 

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Re: Enrichment problems? CIS K-Jet guys: Try this mod! (agropena)

quote:[HR][/HR]where in the engine compartment is locate the warmupregulator?
[HR][/HR]​
It's located on the engine block. Just above where the oilpan is, about halfway along the front of the block. There'll be two braided fuel lines going to it and an electrical connector. It shouldn't be too hard to find.
 
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