MK1 1.8 8v cold rev limiting!!

[xaviersolo136]

Need some help!!!

Heres the issue, its a 93, 1.8 8v kjet cabrio golf. When it is cold it starts fine and idles fine, but if u put ur foot down it will cough and splutter its way up to about 3000 rpm and then its as though it hits a wall, it will NOT rev any higher no matter what you do.

After about 10 mins and when its presumably warm, it will decide all is hunky dori and it will suddenly take off like a scalded cock if u have ur foot down in an attempt to go anywhere. Even with it revving at 3000 it has no power whatsoever, not enough to get up the smallest of hills.

This problem is corrected for a matter of months if you play with the adjuster pin in the fuel distributer, but gradually it gets worse and worse again until it is un-drivable. Any suggestions???

It shouldnt be the Aux air reg as that is effectively redundant when the throttle is open, and it idles properly when cold, but i checked it anyway as suggested. And as it is a problem that gets progressively worse after correcting it it seems as though perhaps twiddling with the adjuster pin on the distributor may just be disguising another problem... or not...

Vaccum system checked, throttle body checked, Fuel pump and circuit have been checked, pressure in the lines checked etc etc (Im assuming it to be a fuel system component related issue)

What do you think? Help appreciated as re-tuning it every month or so is a damn pain!!!

[Dan]

Hi, don't know much about 93 cabrios...is that still k-jet or is it actually Ke-jet?
If it is k-jet i am guessing it is the warm up -reg on the front of the block. Sometimes the metallic strip inside can actually break. Anyway, if it is j-jet it does sound like a control pressure issue. Can you confirm it is K-jet?

[gldgti]

does it do that same thing free revving (in neutral)?

i'm really guessing, but lack of fuel seems reasonable, esp the sputtering when open throttle.

[WABIT]

its just k-jet mate i have one too

wabit

[xaviersolo136]

Just to confirm, it is K-Jet and it does splutter etc when revved in neutral.

[h100vw]

Warm up regulator would be a likely candidate. You would need to do the tests detailed in a Haynes manual or replace it to confirm the problem.

The warm up reg alters the fuel pressure in the fuel distributor, which lets the flap move a touch higher, allowing more fuel in, during the first few minutes of running.

When they fail it is as if they are stuck in the warmed up setting. Consequently you get a weak mixture which the engine isn't happy with.

Gavin

[cab93]

Any luck? Anyone know of a business that can deal with its repair or service? I sorted the wavy idle, and now its has the same symptoms has yours. I hear an audible click just as normal service is resumed. Sometime this happens when restarting after the engine is fully warmed just not as severe. As in your case its back to normal after 10 minutes. Would love to get it running like new!

Michael.

[xaviersolo136]

So far no luck, but i am suspicious of the warm up reg as directed. I did the tests in the Haines manual, it specifies 11.5+ volts which i have, but its ohms resistance, specified at 20-26 is only 18.3.

Does anyone believe that this is a large enough fall in resistance to be causing the problem?

[Dan]

Not sure about your test results there mate, i am not a k-jet expert, but i have owned 3 k-jet golf and one had major issues which took a crazy amount of sorting out, we touched every bit of the fuel system... (don't worry revnit it was not your car ) You can definitely find out by testing the fuel pressure- bit hard to tell the exact effect of your electronic test results- I can photo ( i do not have a scanner) and email you the BOSCH manual pages so you can test the pressures that relate to the warm up reg. PM me your email address if you have access to a fuel pressure test kit.