Bosch

Please restrict your questions and replies to Capri related technical issues!
Post Reply
Noel Reeve

Bosch

Post by Noel Reeve »

Does anyone know anything about Bosch K-Jet fuel injection as fitted to the 2.8i ??

Mine has been sitting idle for a year, and now it runs like a dog (difficult to start, misfires, pops and farts, spits back through inlet, total lack of power, almost undriveable).
When it went off the road last year (following a crash) mechanically everything was spot on and it run perfectly, having just had a new fuel pump, warm up regulator and air valve. Thankfully said accident did not harm anything in the engine bay.

I think things maybe just need cleaning up and connections checking, but I have NO IDEA at all where to start! It's not that I don't understand how the fuel injection works (because I have a basic idea), but in terms of fault diagnosis I just look and it and see a load of pipes and wires.
I am a bit stumped.

Ta, Noel.
guitarswet
Posts: 334
Joined: Mon Jul 28, 2008 8:23 pm

Bosch K-Jetronic

Post by guitarswet »

Noel

There is a book you can buy on the Bosch K-jetronic system. I know Burton power have it printed in the back of their new catalogue (which is very informative by the way).

I would start at the start - that is at the coil. Make sure you are getting a good strong spark out of the end of each HT lead. You can buy these cheap spark testers where you increase the gap until the spark won't jump it anymore.

Assuming you have a good spark going into the plug and the plugs are in good shape then your problems must lie with the fuel delivery. Is it possible that the injectors might need cleaning? There are quite a few sensors on the injection system which can fail and cause problems. I also know that the throttle plate that rises up and down can stick and cause problems. But if the car starts OK then you can eliminate a lot of things associated with the fuel injection system as they are mostly associated with improved starting and warm up. If she runs rough when up to temperature than there must be something more obviously wrong.

You say the car has been off the road for a while - is the petrol 'old' as well. Petrol does go off after about six months. You may want to fill her up with some fresh stuff plus some injector cleaner.
Noel Reeve

aha

Post by Noel Reeve »

Didn't realise there was a book, might have to invest in that.

As regards the spark, I haven't really checked that thoroughly, so will do so. The plugs are new and so are the ignition leads. Maybe the dissy needs cleaning? obviously won't be a points prob as there aren't any.

I suspect it might be the plunger thing under the fuel distributor box sticking, since it will tick over fairly smoothly, but when you open the throttle up it sort of dies as if it's starved of fuel (hence the rather violent spitting back). Maybe that's not moving freely enough and hence increasing fuel flow? I've got some carb cleaner to spray round it and check it moves OK.

The petrol is fresh LRP, so it isn't that.

Thanks for your ideas.
Noel Reeve

admission

Post by Noel Reeve »

I have cleaned all the intake bits thoroughly with carb cleaner, especially the plunger in the fuel distributor, which was well caked with deposits, but does seem to move up and down freely.

No change, still runs like a dog.

I have an admission to make though. During the crash, the axle moved around a bit and interfered with the fuel lines close to the petrol tank, where they run along the chassis rail. The fuel return line was severed and I had to replace the last 10 inches or so. The supply line was squashed a little flat, but not punctured, so I left it as I did not want to disturb or put joins in a high pressure fuel line.

Could this restriction be causing low fuel pressure and hence the symptoms described, where the engine will idle fairly OK but die when you open the throttle (and eventually spit and fart back through the inlet) as if the mixture suddenly leans out ??? Is it just that when I open the throttle the distributor tries to increase the flow to the injectors but cannot because there is too little pressure in the system?

That would seem to make sense, but I have no gear to test the fuel pressure.

Does anyone know if I'm still barking up the right tree?
Post Reply