KE-Jetronic Fuel Injection testing

[DaveDorson]

Anyone got any tips on testing the operation of Bosch CIS KE Jetronic Fuel Injection.

 

I've got pressure gauges and the correct kit for the higher pressures of KJet, but I'm really after some reference values.

 

Car is an 89 w124 3.0 12v (m103) mercedes

[spike60]

Been there, got  the T shirt etc, A 1989 W126 3.0 12v m103 was about 76psi from memory but that wasn't the full picture, you need a pressure differential between the two parts of the fuel distributor which is where my problem lay. What's it doing or not doing?

[spike60]

That post may have made it sound like I know all about them, I don't. Any knowledge was gained with a lot of trial and very nearly as much error but if I can offer any insight I will.

[steveo3002]

get the bosch repair manual and a pressure gauge ...check it out as per the book 

[DaveDorson]

Been there, got  the T shirt etc, A 1989 W126 3.0 12v m103 was about 76psi from memory but that wasn't the full picture, you need a pressure differential between the two parts of the fuel distributor which is where my problem lay. What's it doing or not doing?

 

Turns over, gets spark, plugs are bone dry.

 

Seems to be fuel at the meteringhead/fuel distributor, but not tailed off the pressure yet to check that. (cracked off a cold start line last night and there was fuel in it).

 

Not compression checked the car yet, may well do that tonight if time permits it.

 

Will also pull the injectors out and test them to make sure they're actually spraying when I move the flap..  The seals that hold the injector into the plastic bung didn't look great.. I'll buy some of them.  Don't fancy pulling the plastic bungs out though unless I really need to.

[DaveDorson]

get the bosch repair manual and a pressure gauge ...check it out as per the book 

 

I've just found a PDF download of that from DMC News of all places.

 

I'll see if I can get that done tonight.

[spike60]

Yours is a very different problem to mine, mine was great until it got to 75c then went flat. Sound like you need to check pressure at the head. I would expect it to inject without throttle, mine started instantly like that. Injector seals could make run lean but I would expect it to go. Have you ever heard it run?

Good shout for Bosch manual but it may cost more than the car!  I have a Haynes W124 book and can post the data page if you want.

[DaveDorson]

Yours is a very different problem to mine, mine was great until it got to 75c then went flat. Sound like you need to check pressure at the head. I would expect it to inject without throttle, mine started instantly like that. Injector seals could make run lean but I would expect it to go. Have you ever heard it run?

Good shout for Bosch manual but it may cost more than the car! I have a Haynes W124 book and can post the data page if you want.

I might have that in the workshop somewhere too.

 

It ran previously and I've driven it, had a bad misfire and was very rich, but it's been sat years since then

[fordperv]

Anyone got any tips on testing the operation of Bosch CIS KE Jetronic Fuel Injection.

 

I've got pressure gauges and the correct kit for the higher pressures of KJet, but I'm really after some reference values.

 

Car is an 89 w124 3.0 12v (m103) mercedes

Leave it with me I have an old fuel injection manual which iirc gives checking info I put some bits up on here before, it will probably be tomorrow

[spike60]

If you need any bits Merc are worth a call, I replaced all the rubber bits and bobs around  the idle valve etc plus the big boot from the bottom of fuel distributor with genuine stuff cheaper than Ebay or online specialists.

[steveo3002]

https://www.amazon.co.uk/Tune-Modify-Bosch-Fuel-Injection/dp/0879385707

 

this is the book i used for my k jet....pointless guess at stuff

[chatsharris]

I've got the autodata books at home, when I'm back from work I can have a look if you'd like?

[fordperv]

This is what I've got in my book

 

 

Might be useful for you

 

[DaveDorson]

Zero pressure at the fuel distributor.. the fuel I was apparently seeing in there must have been stale residual fuel.

 

Pump is also incredibly noisy now.

[spike60]

Is the pump noisy because it's knackered or because it's starved of fuel or sucking air?

[Junkman]

I guess the stuff in your tank has silted up.

[DaveDorson]

Is the pump noisy because it's knackered or because it's starved of fuel or sucking air?

 

Dunno.  The tank was try to be honest, the fuel is fresh.

 

I suspect it's corroded being sat either with a tiny dribble in it, or dry.

[DaveDorson]

I guess the stuff in your tank has silted up.

 

There wasn't anything in there to silt up mate.  It'd be drained of fuel before it sat.  I'll blow down the lines when I pull the pump off.

[DaveDorson]

I bought a pump and a filter, I'm waiting for the second pump to appear now so I can get them both swapped over and I'll re-check pressures.

 

absolutely, positively no pressure at this point in time.  Very noisy pump/s and a dribble of piss yellow/gatoraide like fuel coming out the other end when I bleed off the pressure tester.  It's fucked mate©. (or whatever the pump is moving is the crud that was already in the lines.

 

The weekend might well be spent blowing air back through the fuel lines once all the filters and pumps are removed to see if I can back clear whatever might be blocking flow.

[lisbon_road]

I wonder if given the layout, it might not be too difficult to convert it to efi?  

 

Just wondering, and I appreciate that this might be the last thing you want to do.  

[DaveDorson]

I wonder if given the layout, it might not be too difficult to convert it to efi?  

 

Just wondering, and I appreciate that this might be the last thing you want to do.  

 

I want to get it up and running on the CIS and see whether the system works well enough, I don't really want to convert it to EFI as they tend to look a bit lashed in, and I want it to look stock.

 

The M104 fuel rail and injectors will fit, I'd need a proper TPS as the one in there is only a WOT on/off switch really.  There's nowhere stock for a crank position hookup, or a cam position hookup and because mine is actually a non catalyst model, it apparently never had a lambda probe from the factory.

 

Then I'd have to figure out the ignition.  The W124's have a distributor but it's linked to the EZL, which uses resistors for the igntion curve, and you can mess about with them for poor quality fuels to give more retard by moving a jumper pack around.  I'd have to get rid of that and probably run COP or batch spark firing and figure out where to put the coil packs.

It's doable, but it's not a route I want to take if I can help it at the moment.