B21FT Kjet Problem

[Michael92]

This is for those of you who are knowledgeable about Kjet systems. On a b21ft car, I had an clean fuel distributor and lines I had from another car so I swapped them on my car because the lines and body of the one I had was much nicer, and started the car after and it ran great!!..... until I noticed a fuel leak from both of the feed lines into the fuel distributor maybe 30 seconds to 45 seconds into it idling nicely. I had not tightened the banjo bolts tight enough to crush the copper washers and seal it tight so I was spraying a bit of fuel and so not wanting to start a fire I turned her off. Anyway after tightening the fuel lines going to the dizzy, the cold start injector, and the 2 banjos feeding the CPR, I go to start the car and it is taking forever to start, or mostly it is not starting at all..

I changed the plugs thinking maybe my plugs got wet, but nada. Once again to repeat, I changed the fuel dizzy and and the lines leaving only the fuel injectors in this b21ft and the CPR in place. How does it go from starting strong and fast on this changed system, to springing a leak and after tightening the banjos... not wanting to start at all, or starting and running really bad...? but mostly now not starting at all. I don't even hear it fire, it just cranks and cranks.

Any clue?

[Michael92]

Also I forgot to mention the Fuel Distributor no longer buzzes audibly either

[Redwood Chair]

Is the engine wiring harness any good?

[Michael92]

Yes it is, it is really nice no Frayed wires

[the_hairy_baboon]

So it will start, but struggles to do so if it does at all.

Is the timing correct for spark? (rotor points to that little notch when cylinder 1 is TDC)

How's your fuel level? Both fuel pumps running fine?
Pull off an injector and see if it's spraying fuel when cranking - that'll tell you if you're still getting appropriate pressure (since there's a min pressure before it sprays).

[dl242gt]

If those injectors sat around for a few years. They may have clogged with varnish. Moving the lines around while swapping things if there was any old residue in the line it can move down the pipe to the injector.

An injector spray test is really helpful as suggested.

[Michael92]

I got it to start again today and I it definitly is rough. It ran a bit, smoothed out, I shut it off and then it did not start again. I will add some more fuel because I am very low. I don't think low enough to have it be an issue but will add some to be sure. Will keep you posted. Do fuel Dizzy's go bad often? What about the CPR?

[johfraser]

I believe there is a feed line and a return line. Fuel lines are connected to the dizzy? The plugs have to be in contact with fuel in order to ignite the mixture. Test the injector flows by placing them in separate bottles and running the pumps without cranking the engine.

[the_hairy_baboon]

Originally Posted by johfraser

I believe there is a feed line and a return line. Fuel lines are connected to the dizzy? The plugs have to be in contact with fuel in order to ignite the mixture. Test the injector flows by placing them in separate bottles and running the pumps without cranking the engine.

Run the pumps by jumping the fuses with a switch, but you'll also have to take the air hose off the fuel distributor and lift the venturi slightly to see if injectors are working.

If it ran and then once turned off didn't want to restart I'd also take a peek at the accumulator - it's really there to help keep pressure for hot restarts - if it's got a hose that goes back to fuel tank then there's a chance you're not getting enough pressure for hot restarts. No hose style would mean any pressure loss would be seen by fizzing/spitting gasoline out the backside.

Personally my fuel pump issue was a seized sender in the tank as well as a break in the rubber hose connecting sender to outside tube, so below XX fuel level, the main pump would suck air.

[TestPoint]

How much fuel in the tank?

A failing tank pump can cause erratic pick up by the pressure pump and work sometime and not others. The fuel can usually be picked up by the pressure pump if more than half a tank.

[Michael92]

Okay here is an update:

I put the original Kjet fuel distributor back in and it runs like it should

as for the one I put in, it starts rough cold, does not want to start the car after the car has been run, the frequency valve does not buzz, however I took the frequency valve from this unit and installed it on the original one to see if it is working and it is functioning properly. So car runs rough with this fuel distributor, no buzz and with the original FD the car runs properly. This FD would start to run better after it idled for 60 seconds but better not to turn the car off because you are not starting it back up.

Any thoughts of what is the issue with this fuel distributor?

[Redwood Chair]

Junk it.

[TestPoint]

If you are linking the replacement FD to no vibration of the Frequency Valve the only link is through the lean/rich reading of the 02 sensor and lambda module.

Just guessing but the car may be starting on gas from the cold start injector and the replacement FD may not be passing any gas to the injectors. When cold start injector shuts off, about 20 seconds, the engine stumbles to a stop.

The earlier suggestion of sticking the injectors into plastic bottles to verify that fuel is being sprayed is a good one.



Here is what my fuel delivery results looked like after two efforts by a commercial rebuild company looked like. Notice that I did not use the word 'professional'.



Here is the results after my attempt at a rebuild.



DO NOT throw the FD away! They have become too precious. A rebuild kit is about $90 while one from a professional rebuilder is $450+

[dl242gt]

When you slip the precious on. It makes you disappear. Plus you can see dead people.

These systems respond well to cleaning. Try some BG44K and run it through a couple tanks of fuel.