Shortage of fuel at injector lines out of fuel distributor
I will take any thing I can get on this problem.
I have looked at the K-Tronic diagnosis posting and I got nothing..!!
I have the simple K-Tronic with out the Lambda.
My fuel distributor is the cast iron type and not the alloy if that helps...
Symptoms are:
* wont start and run (although it will idle briefly upon first trying to start),
* it is not electrical as i have a ton of spark,
* when cranking engine catches but not quite and it lingers on the starter until you give up...not quite getting to the idle,
* I have changed fuel pump and filter + the gauze filter in the distributor,
* appears to have plenty of pump pressure at the feed line to distributor and plenty at the return side as well, I have not put a guage on to test pressure and flow but I cannot hold back the pressure with my finger ...it pushes through
* I thought maybe a relay but the fact that I have good pressure at the end of the main feedline negated that,
* when I crack an injector feed line at the distributor there is not even a dribble evident,
* so if all else fails is this indicating a U/S fuel distributor and what is the history on these units are they reliable or reknown for playing up.
* appears to have plenty of pump pressure at the feed line to distributor and plenty at the return side as well, I have not put a guage on to test pressure and flow but I cannot hold back the pressure with my finger ...it pushes through
*Cheers
Peter
Hi Peter, first I highly recommend investing in a fuel injection pressure tester. You'll be thankful as just about any diagnosis of drivability problems starts with pressure testing.
About your fuel distributor, think about it this way. The circular/flat plate which moves up and down in relation to intake airflow is one end of a teeter totter (a long flat board with a fulcrum at the middle and one happy little kid sitting on each end; kid one goes up while kid 2 goes down). Deep inside the fuel distributor, the other end of the plate assembly moves up and down changing the fuel flow volume to the injectors.
So...first you want to verify the plate moves...and it moves freely. If so, the fuel is being measured and adjusted just fine. But, if the fuel isn't leaving the fuel distributor, there's a significant physical blockage. My experience is these units will get heavy stains but if the ffilters are refreshed timely, there should be no dirt. But old filters can let dirt through. Also, non-use can be a problem. If fuel dries in the distributor, the residual is very bad for fuel flow.
I have taken several apart and cleaned them with lots of carb cleaner and lots of compressed air. If you are patient and can remember how parts go back together it's fun to explore...you never know what you'll find. My goal has always been to clean... but not disturb settings or gaskets...with care this cleaning can be done without having to renew any parts.
So...my bet is dirt and grime inside, if the plate is moving freely. Good luck.
Dave
PS. I apologize for assuming you may be unfamiliar with "teeter totter". If you know what it is that's another reason I should go down under for a vacation...and learn more about my Australian friends.
Dave
firstly thanks for the response and advice.
I will take a look tonight and give some feedback.
You are absolutely right though...I need a pressure guage which i will acquire b4 going fuirther.
That blue sensor that sits on top of the airflow sensor near the venturi....
Disconnect the harness from it,then make a jumper wire with an 8amp fuse inline.
On the harness itself,loop the jumper wire on the two female pins.Try to start.If it starts and runs,replace the fuel pump shutoff switch (the blue sensor) try that and let us know what happens.
Nutz along with what Dave has put to me I am pretty certain I can get the thing up and running again. Will post the reults after the weekend. Have to get a fuel guage firstly so i am 100% on the pump pressure. So please confirm that I am looking for around 5 bar or 75psi at the delivery line to the distributor.
If the pressure regulator within the distributor is playing up though fuel will bypass and it wont matter what the feed rate psi is, so is there a check on that to ensure that I have indeed got the correct pressure within the distributor.
I guess an injector line pressure is indicative of this. So what should a nozzle line be around in psi or is it 75psi through the whole system with the exception of the warm up regulator circuit and maybe the cold start circuit.
Your feedback muchly appreciated.
You've read the K jet sticky in the W116 forum haven't you? Specs are there.
Ok Nutz
thats a good thread for unwary players.
Didnt acquire a fuel pressure guage yet but bridged that cut out switch as you suggested and unforunately...no difference.
I need to get a pressure guage and work thru the system.
Tie off a 14 gauge wire about 6" long to the plate buffer (the flat bar that goes across the venturi) and let it wedge open the plate by running the 6" wire down the venturi (MAKE SURE IT'S TIED OFF WELL).Try to start now.If it starts,the airflow rest height on the airflow sensor may be too great.
Vehicle: My toys: 83 280ce Euro / 78 280ce (the future 560ce) / 74 Triumph TR6
Location: Texas
Posts: 126
I had read this thread a few days ago and thought more about it. Benzhead, you had said the engine would try to start but never achieve idle. One other thing I would check would be the fuel pump relay. The relay will provide a short duration signal to the fuel pump, prior to engine starting, to pressurize the distributor, but then requires a signal from the distributor/ign. module to keep running. At least this is the case on my 83 280ce that incorporates the rev limiter in the fuel pump relay. If the fuel pump relay is faulty, the engine will try to start but not achieve idle as you described. One check is to remove the fuel pump relay and jumper across the two pins that power the pump, I think they are #30 and #87 but I'd have to check to make sure. This will make the pump run continuously even without the engine running so you don't want to leave it in. If the engine starts and runs, then you know it's a bad relay.
Linear Mode
