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Engine Specific Info and Questions => IDI Engine => Topic started by: kidmogster on May 07, 2010, 05:58:36 pm

Title: no start unless throttle pressed
Post by: kidmogster on May 07, 2010, 05:58:36 pm

Hi, new guy to the site, I have a 1994 jetta 1.9 turbo diesel and will no start unless throttle is pressed half way. Is this normal since i just bought this and not sure. Car has 327,000km. Once started it idles good and drives great with no smoke. So far thats my only concern,thanks Gary

Title: Re: no start unless throttle pressed
Post by: Smokey Eddy on May 07, 2010, 06:25:46 pm

Weird. That is odd.

with the pedal down a bit does it stumble to start or does it start on the first stroke?

you might try turning up the "residual fuel screw" which is at the back of the pump close to the head. the throttle lever rests on it. it should make sense that it would increase the fuel a bit on idle.

OR you might try advancing the injection timing slightly by loosening off the 4 bolts that hold the pump in place and gently rotate it towards the head a fraction at a time.

loosen it up a bit (still should be stiff, not flopping about) and gently tap it towards the head with a rubber mallet or something similarily as soft. try starting.
no go, try a little further.

I'd do that after i increased the fuel on idle.

Title: Re: no start unless throttle pressed
Post by: Runt on May 07, 2010, 06:35:12 pm

Most, if not all diesels need a large injection to get them started.  There is a part of the linkage within the governor/speed control assembly that is supposed to give you full throttle to start it.  I'd suspect that you either have a sticky spot in the sliding portion of the governor shaft, or you have a problem with the speed control assembly.
Either way, I think that you are probably looking at having the pump gone through, though if everything else works fine, I'd just run it for now.  Unless your idle is low, I'd probably not try to compensate by adjusting the residual fuel screw.

Title: Re: no start unless throttle pressed
Post by: FoXBoXRaCiNG on May 07, 2010, 06:54:32 pm

Sounds like it runs good after the startup, perhaps a cheap place to start in my opinion is glow plugs ??? Vince Waldon has a nice writeup in pimping the glow plugs on the cheap!

Title: Re: no start unless throttle pressed
Post by: kidmogster on May 07, 2010, 09:52:32 pm

just to update while running i can see bubbles in the fuel line to the injecton pump

Title: Re: no start unless throttle pressed
Post by: rabbitman on May 10, 2010, 11:50:40 pm

Quote from: kidmogster on May 07, 2010, 09:52:32 pm

just to update while running i can see bubbles in the fuel line to the injecton pump

That isn't good for anything.

Maybe run a quart of ATF through the fuel system.