I have a 79 244 with 2.1 and ke jetronic. Did not run(had been sitting) when I got it, fuel pumps were not working. So far I replaced the in tank pump and fuel pump relay. What it is doing now is, with the key on both pumps run continually and the engine floods. With the no.7 fuse out, key on, tap the fuse so pump runs momentarily and it fires and runs until fuel is burnt up, last thing I tried was, tap fuse to get engine to start and after it starts put fuse no.7 in and the engine dies immediately( unless you pull furs before it dies and most times it’ll recover.

 

first off, the engine shouldn't flood with the pumps running, unless the air meter is stuck open, or you have leaky injectors.

K-Jetronic has a pressure differential test, requires a pressure gauge with fittings to the upper and lower chambers of the fuel distributor, at zero air flow, the pressure should be below that required to pop open the injectors.


old K-jet injectors are problematic, they typically last 10-15 years and need replacing. but first sort out the air flow meter and fuel distributor. hardly anyone professional knows this stuff anymore, as volvo switched to EFI in 83.

 

The air meter moves freely. With the injectors pulled out and the key turned to the on position so fuel pump runs the injectors spray a fine mist.

 

the injectors should not be spraying at all with the air flow plate in the rest position. that either means the fuel pressure is too high in the upper chambers of the fuel distributor, or the injectors pop-off valves are stuck open.

[note, btw, I've only actually dealt with CIS-E systems on Mercedes and VWs, but the Volvo stuff should be pretty similar].

 

They should not spray - the higher the plate, the more fuel, and at rest there should be no fuel - there is an adjustment, you will need a shortened/cut down 3mm allen wrench with a half cut off T handle on it - that fits into the little hole between the fuel distributor and the rubber boot between the air metering plate and the throttle housing. Turning clockwise makes it richer. - But I can't imagine anyone setting the mixture that far off to make injector spray - So

The first thing I would do is to check fuel pressures. Three pressure are read - Line, control, and rest. I can't imagine diagnosing a CIS fuel system without a fuel pressure gauge (that can fit as previously described) The rectangular silver box with two hoses and an electrical connector next to the boot is the control pressure regulator - it controls the downward pressure on the plate, resisting the air flow attempting to push it up. When the engine is cold the regulator put less pressure, allowing the plate to go higher and deliver more fuel, like an automatic choke.

 

Finally messed with the car again. I played with the air flap in the metering box, moved it up and down as well as pushed it down lightly to make sure it was seated. After I did that I could feel resistance( even slight resistance) through the entire travel and it moved up more. I did however realize that it may not be flooding. With the no. 7 fuse in the ignition will not fire, it is as if you turned the key off. Any ideas on that one? I jumped power from battery to + coil and it did the same thing so I’m guessing the problem is on the trigger (-) side.

 

The car is running well enough to drive now, though it needs to warm up about 20min before you can drive it. I found that one wire(the white/red one that goes across the firewall) when connected would kill the ignition. If that wire(the white/red one hanging down in one pic, same one going across firewall) is disconnected while the other white( red heat shrink at the terminal end, also the one that goes to ignition module) is connected the ignition works and the car runs. I’m guessing they are both intended to be connected to the coil so I’m hoping you guys can give me some insight on the issue.

 

Is there a good book on kjet? I need to learn more about the system as I’d like to keep it and be able to diagnose and fix myself.

 

the two side terminals on the coil are '15' and '1. 15 should be connected to power when the ignition is on (II/run and III/start). pin 1 comes from the ignition timing, be that electronic, or breaker points, and is momentarily grounded each half turn of the engine to fire the spark. What is that white thing with the red and black wire along side the coil, it looks like a fuse holder ?!?

re: a book on CIS/CIS-E aka K/KE-Jetronics? I believe there was a rather good Bosch book on it but I've not seen one in 20 years.


ok, I'm assuming you have the electronic breakerless ignition (eg, there's a hall sensor in the distributor and an electronics module, rather than breaker points)

following is the ignition and K-Jet injection... that skinny grey thing in series with the coil power drawn just above the coil is a ballast resistor.

 

I understand how a coil works. That plug is for an hei module. I am wondering what the second wire on the - coil terminal is for and if I need it. As of now the engine will not run with the second wire connected to the coil, yet when we got the car it was connected. With it disconnected the engine runs though it is very cold blooded.

 

i see that 2nd red/white wire going to the fuel pump control relay/module "J" on the second diagram. I would assume that's so the fuel pump stops running when the engine isn't turning over.

 

oh, and I do see the ballast resistor down under the coil tucked against the body in your 2nd photo.


the "A" module on the first drawing of mine is the equivalent of an HEI, its an ignition amplifier that takes the signal from the hall sensor and boosts it to fire the coil. on early volvos like the 79, the timing is vacuum and centrifigual, on later cars (85+?) there's a chrysler or bosch electronic ignition control unit instead that does the timing, temp compensation, etc.


btw, that box with the red wires at the very top of both drawings is the 'positive terminal', its a black plastic chiclets style cover with a bus bar inside that has all the raw + stuff coming directly off it, on 240's I've seen its on the left fender near the spring tower.

 

Thanks for the info and diagrams. I do need the second wire connected as the pump runs constantly as soon as the key is on. I do not understand why it kills the ignition. I will have to check again but I’m pretty sure the pump runs constantly even with that wire connected.

 

maybe the electronics part of the fuel pump relay is fubar then. in the FI drawing, you can see the insert on the lower right shows where power is when the ignition is on but the engine is not running, and the fuel pump relay is 'off'. it takes the timing pulses from the distributor to switch it on normally.

 

ah, here's some stuff on that K-Jet fuel pump relay...
https://www.240turbo.com/fuelpumprel...ner-kjet-relay

this green relay is under the dash, above/behind the fuse panel

 

We have replaced the fuel pump relay, maybe I should try the old one. I thought I had read something about the ignition “triggering” the fuel pump but was not clear on that. I did noticed, from the many times we pulled the no. 7 fuse while doing test, that every time you put the fuse in you can hear the relay click. Anytime the fuse is in the pump runs as soon as the key is on and stays running.

 

I tested the car with the old fuel pump relay and the pump does not run with key on like it does with new relay. However it needs the extra wire connected to the coil to get a signal to operate yet the ignition does not work with this wire connected so the new relay is back in. Most recently I installed a new 02 sensor( figured it couldn’t hurt) and a new fuel filter(at the firewall, which definitely had a restricted flow) now the engine barely runs. I removed the idle control valve, warm up regulator/control pressure regulator, cold start injector and one more piece to clean and bench test. I recalled that the previous owner said he diagnosed the vehicles poor running( reason he stopped driving it) and the culprit was this part but I can not figure out what it is called.

 

That is a "frequency valve". Only used on later cars with oxygen sensors. It's not on the wiring diagram shown earlier in the thread. That diagram must be for a pre- o2 sensor car. The frequency valve Adjusts the fuel mixture and the cars don't run or run bad when not working. It should audibly buzz all the time. No buzz? There is a relay for it - I think it's under the hood on the left side - between the strut tower and the battery. (it's been a while) The O2 sensor on those early cars did very little - usually made the cars run bad. Leave it disconnected. When I did the first generation Emission inspections in the late 1980s - early 90's - many times when the car was clean and passing, they ran bad, sluggish,and lacked power. A mixture adjustment and disconnected o2 sensor made all of the 118 hp available again!

 

I don’t think I’ve ever heard a buzz in the engine bay, can I get a new frequents valve somewhere? Is it more common that the relay is bad the frequency calve being bad?

 

I never saw a bad frequency valve - (of course last time I worked on one was maybe in 1995) it was always lack of power to it. It's a soft buzz, you might need a stethoscope, or long screwdriver on it, to hear -