# CIS-Basic, no fuel at injectors, a little help?



## Lord_Verminaard (Apr 6, 2004)

Ok, long story short, Mk1 Scirocco with Audi 3A engine, someone had swapped a CIS-E system in it. It never ran right. So I pulled it all out, kept the knock-sensor ignition, and put in a CIS-Basic system. (no lambda, no frequency valve, BASIC!)
Before I go into what it's not doing, here's what it does have going for it:
Main electric fuel pump is new. (and for real new, not a good used one or pulled from a junkyard, it's NEW)
Injectors are all known good ones, they came from my 84 Scirocco, perfect spray pattern, they replaced the CIS-E injectors which were all bad.








I have 3 CIS-basic metering heads here, I've tried 2 of them so far with the same result.
CPR- unknown condition. I also currently do not have a power source hooked up to it, but it should not matter other than making the car run more rich for a longer period after startup.
Port to cold-start injector is blocked off, no fuel line going to it.
Here's what happens. I hooked everything up, left one injector out so I can test and get basic settings down. Hooked up my Jeep with jumper cables to the battery so I can test and not run the battery down, also to verify I am getting enough voltage. I jumper the relay, fuel pump runs. Injector sprays a little fuel, then stops. I hear a slight, rhythmic clicking coming from the fuel dizzy, about once every second or so, sometimes it speeds up, sometimes it slows down. If I pull the airflow plate up, I can feel the resistance build and on every click, it loosens up again and repeats. When lifting the airflow plate and then dropping it quickly, there is a slight delay when I feel the plunger hit the plate arm. I crack the fuel lines to the injectors, I get fuel coming out. Actually, I cracked every fuel line coming to or going from the dizzy and both lines on the CPR, I get fuel out of every line. But NO fuel from the injectors. Even when raising the airflow plate all the way up. When cracking the lines, the fuel coming out sprays in the same rhythmic pattern as the clicking. I have swapped the dizzy heads once and got the exact same result.
So what the heck is going on? I do not have the means to do a system pressure test, but with a new fuel pump and swapping the heads that wouldn't be a problem. The only unknown is the CPR- but I've never heard of a faulty CPR preventing fuel from coming out of the injectors. Another thing I thought of was air in the lines, but I cracked all the lines several times and I would think that would be enough to free it.
Thanks so much in advance.








Brendan


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## hogg (Oct 2, 2007)

*Re: CIS-Basic, no fuel at injectors, a little help? (Lord_Verminaard)*

no expert here but if you get fuel to the injectors but not spraying, then it's not enough pressure. Just cracking the lines doesn't tell you the pressure and it's my understanding that it takes alot to make these injectors open.
changed fuel dizzy so it's not blocked.
The "pulsing" spray tells me your pressure is pulsing
Some blockage "before" the pump?
Almost out of gas? (a long shot but...)


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## Lord_Verminaard (Apr 6, 2004)

*Re: CIS-Basic, no fuel at injectors, a little help? (hogg)*


_Quote, originally posted by *hogg* »_no expert here but if you get fuel to the injectors but not spraying, then it's not enough pressure. Just cracking the lines doesn't tell you the pressure and it's my understanding that it takes alot to make these injectors open.
changed fuel dizzy so it's not blocked.
The "pulsing" spray tells me your pressure is pulsing
Some blockage "before" the pump?
Almost out of gas? (a long shot but...)


Pulsing, yeah, that's what it's doing. I stuck my head down by the pump and it is whirring at a constant rate, and the "pulsing" is not heard or felt at that end. There is plenty of gas in the tank- and this car was running on CIS-E not long ago so nothing has changed accept the addition of the CIS-Basic stuff and the CPR. 
Has anyone ever had a problem with air in the fuel lines? The dizzy head was installed empty, so was the CPR and all of the lines were pretty much dry. How would you go about bleeding off the air in the system? I've searched and it does not seem like anyone else has had this problem.
Thanks for the ideas, keep 'em coming.
Brendan


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## PASHAT (Oct 23, 2006)

*Re: CIS-Basic, no fuel at injectors, a little help? (Lord_Verminaard)*

I sure don't know much about CIS-Basic, but your problem is consistent with a bad in TANK pump. Without the transfer pump working properly, you don't get fuel to the fuel dizzy in appropriate quantities.
Some of the older systems did not have in tank pumps though...not sure if yours is one of them.
It could also be a FPR issue, where there is no pressure as fuel is returning effortlessly to the tank.....
Open the line from the main fuel tank and put the end in a jug. Jump the fuel pump relay and watch the flow for a few minutes, then report back on what you see. If it "pulses" you know that your problem is on the fuel pump side of things.
Also, the pressure on the plunger in the fuel dizzy should be very hard. Not too bad to push using the plate, but it should hurt your finger to push it in directly....


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## Lord_Verminaard (Apr 6, 2004)

*Re: CIS-Basic, no fuel at injectors, a little help? (PASHAT)*

Thanks for the reply.
Ya, this car does not have the in-tank pump assembly. And the main pressure pump is new, so unless there was a fluke incident with the pump, it should be fine.
The fuel system pressure on CIS-basic is controlled by a spring-loaded plunger that is bolted in to the side of the dizzy head. I removed the Diaphragm pressure regulator that was present on the CIS-E unit- which, to my understanding, keeps the system pressure at a pre-determined level and is used in place of the plunger system on the older CIS-basic units. Or does it do something else?
Either way, fuel is going in and coming out. What's the cheapest way I could measure the fuel pressure? My financial situation is dire right now, besides the holidays, we are also moving at the end of the month.








Also, why would the injectors spray a little fuel right when I started this experiment, and then stop and not spray any more?
Thanks,
Brendan


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## PASHAT (Oct 23, 2006)

*Re: CIS-Basic, no fuel at injectors, a little help? (Lord_Verminaard)*

Is it possible that yours NEEDS an in tank pump? Might have to change the tank. How is fuel flowing to the main pump?
Check the flow out of the main pump, like I suggested. Also, check pressure by testing how hard it is to push in the fuel dizzy plunger. that should give you some idea of what is going on without a fuel pressure guage. 
Check for consistent fuel flow where the injector lines attach to the fuel dizzy. Raise the fuel plate all the way. Again, don't just crank it and see that there is some fuel, watch it for a minute or so.....I know its hard when gas is expensive, but you really do need to know this....
No Sparks when you are doing these tests. NONE!


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## Lord_Verminaard (Apr 6, 2004)

*Re: CIS-Basic, no fuel at injectors, a little help? (PASHAT)*

Fuel goes to the main pump with gravity- IE the tank has the outlet going out at the bottom of the tank through a short (4") rubber hose to the main fuel pump. The return line goes in through the top.
I forgot to mention, the plate does take a bit of heft to lift, it's not just flopping around in there. I've messed with CIS long enough that to me it feels "normal". The "pulsing" felt through the plate is not strong but noticeable. I did lift the plate while one of the lines was loose, and it went from a slight dribble to blasting fuel all over the place- seemed pretty good to me.








Any thoughts on air in the lines?
Brendan


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## PASHAT (Oct 23, 2006)

*Re: CIS-Basic, no fuel at injectors, a little help? (Lord_Verminaard)*

So...good fuel flow at the outlets for the injectors?
If that is the case, pull the injectors...all of them, and check for spray. Run all the injectors into a container for 30 seconds with the plate lifted. Measure the volume. Check the spray pattern on each. Replace the 0 rings on the injectors while you have them out, if you haven't done so recently.
Air should be pushed out of the lines already....but the 30 second flow test should reveal any air problems....
You are using the steel dizzy, not the CIS-E aluminum one?


_Modified by PASHAT at 9:30 PM 12-17-2007_


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## hogg (Oct 2, 2007)

*Re: CIS-Basic, no fuel at injectors, a little help? (Lord_Verminaard)*

"Injectors are all known good ones, they came from my 84 Scirocco, perfect spray pattern, they replaced the CIS-E injectors which were all bad. , "
"I get fuel out of every line. But NO fuel from the injectors. Even when raising the airflow plate all the way up."


no fuel coming from injectors that are known to be good and there is fuel going at the injectors means there isn't enough fuel pressure


_Modified by hogg at 8:14 AM 12-18-2007_


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## Lord_Verminaard (Apr 6, 2004)

*Re: CIS-Basic, no fuel at injectors, a little help? (hogg)*


_Quote, originally posted by *hogg* »_
no fuel coming from injectors that are known to be good and there is fuel going at the injectors means there isn't enough fuel pressure

_Modified by hogg at 8:14 AM 12-18-2007_

So I guess what it boils down to is sorting out my fuel pressure. Which means I need to engineer a fuel pressure gauge somehow... Great. Any thoughts on the cheapest way to do that?
Brendan


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## wclark (Mar 28, 2001)

*Re: CIS-Basic, no fuel at injectors, a little help? (Lord_Verminaard)*

Your symptoms are those of too little fuel pressure (below about 4 bar). The pulsing of fuel from the injectors is probably the result of fuel pressure exceeding the injector shutoff springs closure pressure then droping off again.
You need to test your fuel pressure, cracking a fitting will not tell you if you have 3 bar or 6 bar.


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## PASHAT (Oct 23, 2006)

*Re: CIS-Basic, no fuel at injectors, a little help? (wclark)*

Why not just run a stock 9A in line Fuel Pressure Regulator on the return line? You should be able to get that from any 1990-1993 Passat 2.0 l. Probably lots of others would do, but that is the only one that I know about....
If pump is new and getting gas, then your problem is your FPR, I would think. Wonder if you can try blocking the return line and see if the injectors spray then?


_Modified by PASHAT at 12:13 PM 12-18-2007_


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## Lord_Verminaard (Apr 6, 2004)

*Re: CIS-Basic, no fuel at injectors, a little help? (PASHAT)*

I actually have one of those from the CIS-E system that I removed. Problem is, the CIS-Basic unit has the pressure regulator built in on the side of the unit. Besides that, I've swapped dizzys which means two different pressure regulators with the same result- so I'm not getting enough pressure to the injectors, some way or another.
I'm going to re-check my connections, I may have a line swapped on the DPR or dizzy-side, I've been reading diagrams all day and something as simple as CIS starts to look a little blurry once you've been fooling with it long enough.








Brendan


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## Lord_Verminaard (Apr 6, 2004)

*Re: CIS-Basic, no fuel at injectors, a little help? (Lord_Verminaard)*

Figured it out. Cause? A severe case of dumbass.







I had installed one of the "check-valve" banjo bolts on the inlet of the fuel distributor. When assembling this stuff, I had a big "box o banjo bolts" that I was pulling from, didn't even pay attention to the check-valved thingy. I did have the correct check-valve bolt on the filter (since that didn't change) but I also had one on the inlet from the filter to the dizzy. Ya, that'd do it alright. Swapped bolts and ran the pump and low and behold, fuel at the injectors!
Didn't get a chance to turn it over though, the battery was low enough to not be able to spin the engine, even with the Jeep jumpered to it. (Jeep's battery is getting sucky too)
Round 2, putting everything back together and maybe getting it to fire. Not a moment too soon either, move-out date is in 10 days.









Thanks for the replies everyone. Once springtime rolls around I'll be sure to do some pressure tests.








Thanks again,
Brendan


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## hogg (Oct 2, 2007)

*Re: CIS-Basic, no fuel at injectors, a little help? (Lord_Verminaard)*

now i feel really bad 'cause there is a thread here somewhere that mentions that check-valve bolt giving trouble. 
need to commit that to memory fo next time


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## PASHAT (Oct 23, 2006)

*Re: CIS-Basic, no fuel at injectors, a little help? (hogg)*

Check valve Banjo Bolts? I am not familiar with those....are they just for CIS-Basic? Don't recall coming across them with CIS-E. Would appreciate learning about them...


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## Lord_Verminaard (Apr 6, 2004)

*Re: CIS-Basic, no fuel at injectors, a little help? (PASHAT)*

Ya, this little guy right here:



I'm pretty sure the CIS-E and M variants have this too. (at least the setup that was swapped in my car did, which was how I ended up with a few extra) It's the 17mm one on the outlet of the fuel filter. It's basically a one-way valve so when you shut the car off, it keeps the fuel from draining back to the tank, also helps keep it under pressure to prevent vapor lock. Since fuel only goes through it one way, I had one on the inlet of the dizzy, and well, it wouldn't let fuel through.








Notice the spring visible inside, the brass plunger on the "screw" end, and the little notches in the hex. I work in a dark garage, so it was easy for me to just grab the first 17mm bolt I saw in my bag-o-banjos. 
Just a DUH moment! I guess it's happened to a lot of people, especially after changing out a fuel filter.
Brendan


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## PASHAT (Oct 23, 2006)

*Re: CIS-Basic, no fuel at injectors, a little help? (Lord_Verminaard)*

Thanks....I seriously did not know about those. So, instead of me helping you, you helped me. 
http://****************.com/smile/emthup.gif


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## tdipower4me (Dec 1, 2005)

hey, i'm having the same exact problem but i drilled out the filter thingy in the banjo bolt. it didn't run with the check valve and it doesn't run without it ethier...


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