Starts spitting at 6K rpm

**82cab** · 06-07-2006, 03:33 PM

OK i did a kr 16v conversion with K-jet in my mk1, and still trying to get it to run right.

My problem at the moment is that when i take it up to around 5500-6000 rpm @ full throttle, the engine seems to starve and spit. It pulls really well until i reach those revs.
I don't think its the timing because the longer i drive it, the engine seems to spit at lower revs at full throttle. When i back off the throttle a bit she runs ok. Plus i can get it to go up to 7500 without spitting by backing not opening the throttle all the way.

So i'm guessing i have a prob with fuel pressure due to a crappy fuel pump that seems to loose its pumping power the warmer it gets.

Does anyone think the same way or am i heading down the wrong path.
Ps what is the fuel line pressure supposed to be for the k-jet system and is there any easy way of increasing line pressure from the fuel distributor?

syncro · 06-07-2006, 03:37 PM

Check all of the easy bits first. Plugs, plug connectors, distributor cap etc.

Usually high rpm problem = electrical low rpm problem = fuel.

Not always like that, but it's a start.

**Golf Loon** · 06-07-2006, 06:16 PM

There is a little filter in some of the fuel metering heads that can get choked.

Also are you running a pressure regulator?

syncro · 06-07-2006, 06:41 PM

Originally Posted by Golf Loon

There is a little filter in some of the fuel metering heads that can get choked.

Only on '85 models

syncro · 06-07-2006, 06:43 PM

Are you using the correct pump? K uses more pressure than EFI.

**gtimk5** · 06-07-2006, 07:33 PM

The KE pump runs much lower pressure than the K pump. KE injection has electrical control at the metering unit.

**DOHCDAVE** · 06-07-2006, 08:17 PM

Running pressure of k-jet i believe is between 70 & 80 psi.
Also are you running a vacum warm up reg it also determins pressure to the sys as the fuel load is raised.
Fuel pump should run cold so start the car raise the rpm slowly the pump should increase in rpm due to less pressure in sys. point is, is the pump running hot if so time to change , they can be intermitant in the way of heating one min there cool to touch the next they're to hot to touch then back again that indicates that the pump is on it's way out.
My 8v EV Gti motor was doing the same thing it had a little knock in the bottom end so i pulled it down to find worn bearings and cracked rings in every pot.
so check that it's not running to lean though they tend to run themselves rich but not in al cases .
hope it helps some as i played with my mech injection for close to a year before getting it right and the thing runs hard to right up to vavle bounce.
good luck.
And i read up top that surgical law aplies wich is important b4 you start playing with the unit prep an area dust free that won't be affected by fuel.
br reconnecting unit always good to run the pump for a while to flush any loose bits floating around in the line.

While i'm talking fuel ALL TAKE NOTE diesels as well check out www.fueldoctors.com.au i have tried it in several cars and it works dyno proven an locally owned in qld .
Cheers Dave
PS. UP THE QUEENSLANDERS

**82cab** · 07-07-2006, 08:21 AM

Ok got up this morning to start the car and it barely started, then it **** itself.
I manualy pushed the metering head to see if the injectors squirted and got next to nothing.

i'm running everything i'm supposed to be running on the k system so it looks like my fuel pump.

I'm going to clamp the fuel return line to see if the system pressures up before i do anything. If i get nothing, its definitely the fuel pump.

the thing was sitting around for a few years so that doesn't really help.

Does anyone have a spare one floating around in sydney?

**82cab** · 07-07-2006, 09:41 AM

Its not the fuel pump. I clamped the return line and got fuel pressure again, so it looks like the pressure regulator in the fuel distributor is the problem. Does anyone know how to repair this or should i just run a seperate pressure regulator outside of the metering head?