I have a 1974 145 and I am trying to troubleshoot the fuel injection system. The Hayes manual I have describes a control unit under the passenger seat, which I don't have, and describes the injectors as having bayonet fittings holding them in place. The injectors I have are held in place by a plate that is shaped like an asymmetric figure eight. Is the Hayes manual for a D-Jetronic and I have a K-Jetronic ?

The problems, which seem to be fuel related, are that :
(1) Usually, when the engine is cold, there is a hesitation when accelerating from a stop that results in a combustion sort of pop noise and then stalling unless I press down on the gas pedal.
(2) Sometimes, when re-starting a warm engine, the engine starts readily and then stalls immediately. Re-starting enough times results in normal operation.

I removed the injectors. One of them was wet. Does that indicate a problem with that injector ?

The connections on the control pressure regulator seem OK. Is this a device that is likely to fail in this way ?

Thank you for any advice.

K-jet has it's own learning curve, and can involve a specialized fuel pressure gauge that allows you to monitor fuel control pressure as the car warms up, but basically, I have found 2 things go wrong.

1. The control pressure regulator has probably failed, if you are getting bad mileage or stumbling running. New ones aren't cheap >$150. Old ones don't work. (YMMV).

Replacing the original with new involves updating to a 240 style. The 140 style had a barbed fitting on top, permanently affixed to the control line from the fuel distributor. If you still have this, it is disassemblable for cleaning, but like as not, it will not work correctly again.

The 240 style CPR has a banjo fitting for the top, and these fittings are fun to find. A hydraulics supplier might be able to direct you to the correct Parker part numbers. Most of the Volvo stuff is for 5/16 hose. YOu will probably have to go up to 3/8 hose and fittings, but then you can use normal HP rubber fuel hose instead of the original nylon type. See the notes the online parts suppliers put in with the 140 CPR. something like "requires upgrade kit".

2. The hard warm start is caused by a failed check valve at the fuel pump. This is also tricky to fix, since it is a barbed fitting into the same type of nylon hose, must be done with heat. The hose is commonly used as air brake hose, but the check valve I haven't tackled yet, and I just deal with a hard hot start. Porsches and mercedes used a lot of k-jet, and putting a check valve up near the fuel distributor seems to solve the problem, but that means dealing with more high pressure hose fittings and adapters.

The fuel distributor is probably okay.

Run a can of SeaFoam fuel system cleaner through 1/4 tank of gas. YOu might get lucky.

If you fuel pump is running pretty smoothly, it's probably okay.

The Haynes manual should have a supplement chapter for k-jet.


Good luck. It runs great when finally sorted out, though, and requires nothing thereafter.

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MPergiel, Elmhurst, IL '74 145e T-5 'Orange Alert'

Also look in the 700 series FAQ, it used virtually the same K-Jet stuff. A wet injector could be a leaking injector. But your problem sounds like maybe the control pressure regulator. I'll see if I can dig up info, both my 760 and 240 had K-Jet and I should have info somewhere (lost most of it when I sold the cars). But the 700 FAQ would be a good starting point.

http://www.volvoclub.org.uk/tech/fuel_injection/k_jetronic.shtml

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...and the bricks keep on rolling

Unfortunately not. Maybe in the future, but that will be a long way off. I'd rather improve my 144. The other day a chrome strip on my 144 got damaged while parked at work, so now I'll take one off the 164.

My wife now works close to my work and she drops me off, so I do not need the 144 as a daily driver any more. Time for restoration.

If anyone wants parts off my 164, I might be convinced to sell. It does have Euro fog lamps instead of US grills... The D-Jet engine runs very well, but the injectors need replacement. Keep in mind I am in New Zealand, not the US.

Yes, it's K-Jet.

Check for air leaks, a slight leak will affect the idle & off idle more than anything. The big concertina hose that connects the manifold to the metering assembly on top of the air cleaner can get cracks in it, take it off & have a good look.

The leaking injector isn't too much of a problem for power, but a new set never hurts. I'm not sure how helpful that would be to your second problem.

Yeah control unit under the seat would definitely be Djet. Yours is Kjet. Other than that you'll have to wait for an answer from someone more experienced with the mechanical fuel injection, I only know the electronic.
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And in the near future Lola 2.0

I appreciate all of your suggestions. At least I know the name of the thing now. I'll be checking out the CPR.