Attn. CIS Guru's....

[Gumba11]

Hey guys,

This is going to be one of my longest posts yet because I think I have a difficult problem to fix.

I have a 77 930 that is running poorly to say the least. It is a 3 litre car that is now a 3.2 running on European CIS. The car is a Euro car.

This problem started intermittantly around a year ago and has become worse over the last 1000 miles or so to the point it is full time.

When you drive around once at normal operating temp it seems to be fine when you are less then 15% throttle. Once you get beyond 15% and get into ANY kind of boost the car falls on its face, smokes black out of the tail pipes, shutters and wants to almost die. Once you lift off the throttle it is fine. So really I have NO driveability at this point at all.

When the engine is cold is the only time it will even kind of idle smoothly and after warm up when at idle I am having to keep my foot on the throttle to keep it running or it will load up and die.

I recently made a post about a frequency valve that I thought was issue but just found out tonight that my car never had a frequency valve or an oxygen sensor for that matter. I have wondered since I bought this car what the blue box with absolutely NO labels on it was for in the rear of the car near the lower seet cushion on the vertical surface there. I am leaning towards the thought that it is a fuel enrichment device from someone. I would think Andial would have put a label on theirs but who knows. It looks pretty old. Looks like early 80's to me.

I will post pictures of the box. I am hoping that someone has some kind of idea as to what this is. I have not got to the point of tracing wires yet but I do see something in the engine bay zip tied to the WUR. It appears to be a frequency valve. Is it possible that this blue box controls it to manipulate the WUR? Please help???

I am very confused and just want my baby to run like it used to!

Thanks in advance for any help here. If I didnt post all the info I should have please ask me questions as I would be glad to answer any and all of them I can.

[RarlyL8]

It certainly sounds like your WUR is involved in the problem.
Much more info is needed on the mods to this engine. A picture or digram of the WUR add-on device and how it is hooked up will help.

[ischmitz]

Chris,

if the blue box is wired to the WUR it is some sort of mixture adjustment. Its principle could be to reduce power through the resistor that's warming up the bimetal spring. This would lead to a richer mixure. Can you run without the blue box? Maybe it is on its way out (capacitors drying out) and pegs your mixture at full rich. Another possibility is that your WUR itself is going bad.

If think the fist step is to check your cold and warm control pressures. This is the only way to get a clear picture. For this you need a fuel pressure gauge for CIS. From what you describe you might be running too rich once you get on the throttle. That would explain all the black smoke.

BTW, read here for some great information about the principle of CIS.

Keep us posted,
Ingo

[Gumba11]

Thanks for the help guys, I will be checking pressures this weekend. I am also curious if anyone has a CIS diagram for a 77 car that would show all lines and electrical connections that would apply in a stock set up. I am affraid my car has had many changes that I want to put back to stock and start over. The wiring work I am finding is also scary. I want to correct EVERYTHING. Last isnt there a chart that shows ambient temp and target pressure for the system? Can someone post this if you have it?

Thanks again for your help!

[Gumba11]

The engine mods are as follows. 3.2 Litre with 964 cams, mild ported, polished, balanced, CC,d, heads are flame ringed, full bay IC, Magnecor wires, stock ignition, K27/7200 turbo, GHL dual 3" muffler with GHL heat delete headers, 8.0:1 compression, and last stock WG and .8 bar spring.

Hope this helps get a better picture of things. I will work on tracing wires and taking photos this weekend as well. Just trying to get as much info going into this as possible.

Thanks again!

[RarlyL8]

Did your engine start life as a 3.0L CIS 930 (Turbo)?

If there are enough issues that you don't trust the CIS at all I would tackle this situation in the opposite manner. Remove evrything and build it back component by component checking everything as you go and leaving out what you don't need.
This add-on device may no longer be needed (if it ever was). Check the A/F throughout the range when you're finished and you'll know what, if anything, needs tweaked.

[Gumba11]

It was originally a 3 litre 930 yes.

Thanks, I think that is the route I am going. I have a call in to Stephen at Imagine Auto. I think they have a system that better manages fuel using parts of the CIS setup. Im not sure yet but am looking forward to his return call.

I will keep you all posted with what I find this weekend.

Thanks,

[schamp]

Maybe a dumb comment but is your distributor in good shape? Spencer

[shbop]

What shape is your turbo in?

[Gumba11]

Distributor has been rebuilt 4K ago and turbo is brand new from Imagine Auto.