Need help with K-Jetronic

[rozment]

I am new to this and all forums, so bear with me. I have an 1985 Vanagon with a 1984 Jetta 1.8l 8V in it. It was previously owned by Kindahippyish and described in this thread: https://www.thesamba.com/vw/forum/viewtopic.php?t=593748. Anyway, my kid got it really hot, I got the head milled down, and put back on. It has good compression. In the process, the one of the wires on the ignition distributor broke, so I got a distributor off Ebay and put it on. I am almost positive I have the timing correct, even though I didn't mark anything before I took it apart and the engine sits at a different angle than original. When I see the second mark on the fly wheel, the 1st cylinder is at TDC and cam mark is at the right/top of the valve cover. So I can get it started, the cold start injector works great, but after it starts, I have to give it lots of throttle to keep it going. It has no power and I can barely get it to move. I have tinkered with the mixture and the timing some and it doesn't seem to affect it much. One mechanic told me I needed another fuel distributor but couldn't tell me what was wrong with it. He also suggested a weber but I am not sure a weber would work at the angle this engine is at. I know fuel is making it to the injectors. I've worked on alot of cars but I no mechanic. I can't diagnose mixture or timing by ear like a good mechanic can. I need either a runner fuel distributor to try out or a good mechanic. I am 60 miles north of Austin and could get it there if need be. Thanks, Robby

[Butcher]

CIS is pretty simple, but many technicians and owners get frustrated by it.

All the air must go through the air flow meter. There should not be any leaks what so ever. Any unmetered leaks will cause issues. The smaller the leak, the smaller the issue. Since you had the head off, I'm certain there were many things removed that could not be installed correctly. Double check that. A smoke tester is the best way, but for certain, it's not in the average DIY'er tool box.

Timing is important and the best way to know is a timing light. Again, this was a common tool in anyone's tool box, but not so much anymore. There are ways to confirm the timing is close, a bit of searching is better that what I could explain.

Obviously the timing is close because the engine runs. Rotating the distributor left or right will change the timing and that can increase the power if the timing is really off. Of course, it's a hit/miss.

There is also cam timing. With the head off, you may have the cam a tooth off. This certainly would cause a running issue. Again, it's close because the engine does run.

If you have to go somewhere, I could call around before I drove anywhere. CIS is getting so old no body wants to work on them. Good parts are getting harder to find. Good technicians are even harder.

[rozment]

Yeah, I've tinkered with timing at the distributor and at the cam. It just seems like a timing issue but maybe I've covered it. A couple of questions: Where does the vacuum line coming off the intake itself usually go? What are the symptoms of problems with the pressure differential sensor? I know there is fuel getting to the injectors but Could there be an issue with 1 or 2 of the injectors? Are the injectors in this system open all the time(there no power to them)? Thanks

[Butcher]

You have a differential pressure regulator? If so, you do not have K-Jetronic.

Which system do you have again?

[kamzcab86]

As I stated in the original topic for this van over in the Vanagon forum (linked in the OP), the fuel system is KE-Jetronic (aka CIS-E), which is an electronically controlled mechanical injection system. In contrast, K-Jetronic is 100% mechanical.

I'm not as familiar with KE-Jet as I am with K-Jet and don't have my manuals in front of me at the moment.
_________________
~Kamz
1986 Cabriolet: www.Cabby-Info.com
1990 Vanagon Westfalia: Old Blue's Blog
2016 Golf GTI S
"Real knowledge is to know the extent of one's ignorance." - 孔子

[rozment]

Yeah, sorry, this is my first vw. Looks like it's ke-jetronic. It has an o2 sensor and a differencial pressure sensor. Should I post again? Anyway, so I haven't paid much attention to the o2 sensor since I figure it's in a loop until it's gets warm, right?

[Butcher]

If the O2 sensor is shorted [to ground] the computer will think the fuel mixture is too lean. Then the system will start to add fuel till it's way too rich. I've seen this in the past where it will lack power.

A simple way to see if this is an issue is to unplug the O2 sensor. That way the computer will not see any signal and will say in the programed 'open' mode.

The KE system is just a K system with a bit more sophistication. Basically works the same, but goes about the fuel mixture control a bit different. I would suggest to Google how this system works so you can wrap your head around how it works and what issues you have.

If you could make a test harness so you can watch the DPR current, it's worth the effort knowing what the computer is doing to attempt to make things right. You will need a good mA tester so if you do not have one and are not willing to make the commitment, then making the test harness would be a waste of time/money.

Again, intake leaks are a big concern. You need to make certain you have none. Thinking is not good enough, you need to know there are no leaks.

[rozment]

Does anybody know a good mechanic with KE-Jetronic experience in central Texas? I'm in Temple, 60 miles north Austin.