K-Jetronic experts?

If you have a leak in your fuel system then that is your problem. K-Jets require high pressures to run, and lack or loss of pressure will result in poor or non start.

My initial thought would be that the problem lies with the Pump, accumulator or WUR, but as you mention a leak then my money is on that

Only ever take a vehicle with mechanical injection to a garage who understand the system. Its beyond me how someone would even attempt to plug it into a diagnostics coms port. The only way to test mechanical systems is the old fashioned way, and thats by checking fuel pressure etc. as per the manufacturers spec.

Try the following:

Turn ignition to prime the pump. And off. Repeat 3-4 times and then start. If it starts quicker now, it might be a faulty fuel pressure reservoir. Part number A 000 476 06 21, 126€

Btw: a '90 car allready has the KE-Jetronic with electronically controlled fuel pressure regulator.

Do you have the factory service manual? Contains lots of diagnosis stuff for the KE. Can be tricky to track down a fault on these. I f you want to keep the car, might be a good idea to 'get into' the KE-Jetronic. Seems like people who know theyr way around the K/KE are getting scarce...

It's part of the fuel pump bundle [26]



But yeah, sort out any leaks first.

From top to bottom: pressure reservoir, filter, pump. I'll give all pipes a good coat with wax on my W123 to prevent future headaches. Also check the fuel line where it goes over the subframe, you might want to put some wax or grease there; they'r usually quite rusty there

Just tried the above, she fired up straight away (and started to pee out fuel from the filter banjo side)
Is there a way of testing the fuel pressure reservoir? I'll change the pipe and fittings first though, pressure might be dropping, confusing the FPR.

Found a good link about KE-Jetronic:
www.coming4you.net/downloads/KE-Jetronic_missing_pages_10_and_11.pdf

Also another photo of the above W126, one mighty parts hauler...
560SEL based:

I'll have a go at the pipe first, and go from there. Fuel filter was replaced not long ago, so all should be clean (Filter is just above the pump on the picture)

Yes, they use the same setup, my OVP relay is fine though, she idles lovely. Just the starting bit that isn't (and that she sometimes stalls when running LPG, but that is fairly normal apparently when using a vapouriser)

Have you got anymore pictures of your car? I'm liking the estate conversion.

K Jet is very sensitive to fuel and vacuum leaks, even the tinyest leak can knacker hot or cold start as the pressures used in the metering head get out of kilter.

Fixed loads of 924 problems jsut by fixing vac and fuel leaks.