Vw 172 GTI

[Mk1sleeper]

Hi Tommie, I hope it's a simple fix, I can't be of much use to you, I'm way out of my depth with tuning K-Jet!
It sounds like Mtech knows a bit!

The cleaner is Sodium Hydroxide ( caustic soda) same isht used in the hot tank for engine blocks and other STEEL / IRON parts. Dont use it on alloy stuff ( disolves alloys )

Build is looking good !

It's actually Potassium Hydroxide one step up from sodium hydroxide. some cleaners are a combo of both, with other additives to keep them in solution, and help with rinsing it off.

[Tommie]

Hi All,

Still no luck with the car. Running out of ideas....
Again the car starts, idles and revs without too much trouble . As soon as you stick it in gear and under loads the car conks out and doesn't want to run.
Things we've changed.....
1. New spark plugs
2. New rotor.
3. New Leads
4. New Fuel pump ( Bosch 044).
5. Set base ideal ( disconnect both vacuum lines).
5. Confirmed fuel pressure sitting about 4.5-5bar at idle and free revving.
6. Swapped Kjet fuel distributor.
7. Swapped Kjet injectors.
8. Swapped coil.
9. Fresh fuel in fuel tank.
And probably a lot more I can't remember.
Please let me know of any ideas.

[dubstar]

You haven't got the timing out by 180deg?

[Mk1sleeper]

Hi Tommie, I'm assuming the car wasn't running when you pulled the motor out?
It sounds like an ignition problem, I'd assumed that they were electronic dizzys, if so check the ignition module, if points check gap and points condition (I only added that because there was a points dizzy sitting in the rain tray of my GTI so now not sure if it's original to the car).
Cheers Scotty.

[Mk1sleeper]

You haven't got the timing out by 180deg?

Nah,then it wouldn't run well without load, if at all.

[Tommie]

Lucky 13 ( Dan) came around this arvo to help me work on the old girl.
We've decided to go back to basics and start at the beginning again.
Checked all 4 cylinders and all 4 checked out fine. Removed and checked spark plugs too.
Next we removed the rocker cover and it looked like we might be a tooth out. Got that sorted and did the timing again.
Few times up and down the street and we have the same issue.
Got it back in the garage, check timing again.
Next we removed the injectors and cranked the engine over to see how much each one is squirting.
Number 1 and 2 injectors had heaps of fuel and number 3 and 4 almost nothing. Seeing that the firing order is 1,3,4,2 that might be our issue. The fuel might be enough for idling and revving, but as soon as its under load it might not be enough.
Will definitely have another crack at it tomorrow........

[GeorgeMK1]

Hey Tommie, after lots of thinking and reading over what you said a few times, I think the issue could be that there isn't a 20vt in there. Give that a try and let me know if it works out! Cheers

[Mk1sleeper]

Hey Tommie, after lots of thinking and reading over what you said a few times, I think the issue could be that there isn't a 20vt in there. Give that a try and let me know if it works out! Cheers

Hey Tommie......There's always one in every crowd!!
Although.................It's a costly fix but it would solve the problem!

[Mk1sleeper]

On a serious note I think you could be on to the cause. Leaning out under load could well cause the problem you've described. Just don't ask me to give any suggestions on why the K-Jet is doing it, other than a blocked line/s!!

Good luck, Scotty.

[roccodingo]

Check the fuel flow delivery rate from the pump. 30 seconds running should deliver 900 mls @ 11.3 Volts. The stuff you stuck in the fuel tank may have choked the outlet line from the swirl pot inside the tank.

Doing the injector test did you raise / lower the air metering plate several times ?? ( bleed any air from the system )

The metering head & injectors you swapped known good units ??

[Tommie]

Hi guys , thanks for the replies and advice. Been hectic lately and no the car is still not running under load.
I am planning to do some more work tomorrow and will give a detailed description then...
Here's a teaser of the car as it sits now, still needs decals/ stickers and few little finishing touches.

[Tommie]

Righto Gents,

Car is still not running, but it might be the dizzy....
So what have been done ,
- Stripped and cleaned Kjet distributor in ultrasonic cleaner.
- Basic set metering head arm to 18.8 mm.
- Ultrasonic cleaned injectors .
- Reshimmed fuel pressure regulator to 4.7 bar.
- Confirmed fuel spraying out of all 4 injectors when cranking.
- Found timing advance was not smooth and was jumping around in increments when revving.
- Stripped distributor. Cleaned and lubricated.
- Centrifugal advance , looks like it moves freely.
- Disconnected and sealed both vacuum lines to dizzy.
- Set timing to zero degrees. Check centrifugal advance at different rpm. Once rpm stabilised advance was in spec.
- Still suspecting distributor issues.

[Mk1sleeper]

WOW!!! She looks awesome Tommie!

How are the shaft bushes in the dizzy that can cause breaking down and missfire under load, however I suspect that there are a combination of small things at play here. It's just a matter of finding them all.

A couple of things that you're probably onto, Cracked dizzy cap, it may look good but a crack can cause under load issues. Is there supposed to be a ballast resistor in the system, Points or trigger playing up, I had a brand new after market distributor in another car (a Holden SHHH!) the advance was all over the shop, breaking down under load, revved freely when in neutral, wouldn't rev past 2500 under load. It turned out to be a combination of the bearing clearances, and a faulty trigger.
I hope my brainstorming is helpful!

Cheers, Scotty.

EDIT: Corrosion on terminals or in wires of the ignition system, check earthing too!

[Tommie]

WOW!!! She looks awesome Tommie!

How are the shaft bushes in the dizzy that can cause breaking down and missfire under load, however I suspect that there are a combination of small things at play here. It's just a matter of finding them all.

A couple of things that you're probably onto, Cracked dizzy cap, it may look good but a crack can cause under load issues. Is there supposed to be a ballast resistor in the system, Points or trigger playing up, I had a brand new after market distributor in another car (a Holden SHHH!) the advance was all over the shop, breaking down under load, revved freely when in neutral, wouldn't rev past 2500 under load. It turned out to be a combination of the bearing clearances, and a faulty trigger.
I hope my brainstorming is helpful!

Cheers, Scotty.

EDIT: Corrosion on terminals or in wires of the ignition system, check earthing too!

Cheers Scotty,

I appreciate all help.
I've tried another mk1 dizzy ( which is running), and still no luck. Decided to open the dizzy, inspect it and clean it . Installed the cleaned dizzy and still no luck. Re- do the timing , advance and retard, and again it runs like ass once under load.
Gone through all the other previous steps as mentioned in the thread and nothing.
Decided to buy a fuel metering distributor repair kit for the Bosch Kjet, so until that arrives there will be no progress. ��

[abreut]

The car looks absolutely awesome Tommie! It will look spectacular with the trim and pin-stripe finishing touches.

I'm not much good with k-jet so can't think of anything you could try there sorry. It does sound like ignition to me as well, but it does sound like you have replaced most of the usual suspects, except maybe the TCI switch? The only other thing I can think of is downstream restrictions ie exhaust. It doesn't have a cat converter on it does it? When they block up the symptoms are similar - car dies under load. If no cat, maybe check the muffler?