T25-Engine Misfire-Pierburg carb connections, Distributor ?

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brucem
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T25-Engine Misfire-Pierburg carb connections, Distributor ?

Post by brucem »

Hi,

First off Thanks for taking time to review this.

From reading other entries, "Forum Etiquette" suggests that i should at least introduce myself before jumping in with the tough techy questions :)

I have recently ( thanks to Mrs M ) obtained a 1983, A REG, T25(3) Camper Van and we have despite a few trials succesfully managed to spend a few night's in it. Having driven one of these for work in the mid to late eighties / early nineties I feel fairly at home with them and it bring back old memories.. :-)

Having acquired the van i have done some off the jobs you'd expect to do..
Oil change
Air filter
Plugs
replaced leaky fuel pipes on tank breater ( scary incident on Garage forecourt never to be repeated )
Figured out how to make fridge work on 12V ( one owner had sneaky additional switch hidden away ! )
Removed the locking wheel nuts the last person had put on and lost key for
bled brakes ( yes rusty nipple syndrome too )

oh what fun we have had over the last month or two.. :-)

So things are going in the right direction, but now I come across a strange one that I'd appreciate the clever guys and gals taking a peek at to see if we can come up with a crowd sourcing solution...

OK here goes...

Photo's and video at end of post !

The van drives fine most of the time when things are taken gently we pottered off to cornwall not so long back. but when the engine is driven a bit harder things seem to go a bit juddery and I think that there might be more than one issue.

The engine is a 1.9 DG recon about 4 years ago.. ( previous owner )

The symptons are that if you rev the engine high it seems to judder / splutter and sometime after driving it til it splutters will stop if you come to a roundabout, if you drive up to 75% throttle things are fine. My initial thought is fuel starvation, but please keep reading !

Having read the other post it seems this could be a fuel / ignition / timing / carb issue so i have been doing a few tests etc and have a few questions to confirm some of my suspicions.

Carb - The carb is a pierburg 2e3 there are pictures below. I have cleaned out the little inline filter and its fine ( i have also as a test run the van with it out for a min or two )

Plugs - Seem in good condition, they are the three prong ones, so should be gapped correctly, a bit oily, but not sure if thats a symptom of the issue.

Air / fuel filters new.

Back to the carb. I have uploaded some pics to photobucket and they are linked below.

The haynes manual and muliple googling have given me a number of pictures of the carb, but not one where it is in situ and easy to see the hose connections. In the van the distributor is connected to an inlet pipe on the bottom left of the carb as you look in from the rear of the van. What I believe is the "choke pull down" a black suction looking device has a vacuum hose that goes around to the other side and connects to one of a pair of hose connectors, the other one of the pair goes to the air box. Is this correct ??

The connection from the card to the distributor... I have run the engine at low / med / high revs and there seems to be no suction from the carb to the dist. ( my old when i was a lad home mechanics with my dear old dad seems to tell me that as i rev up this should suck on the dist to create a vacuum and advance the timing) The seems to be no suck at all when revving. which i think is wrong ??

To the Dist.. On the surface it looks OK, clean , tidy, clean rotor arm, clean connections.. BUT when i suck / blow on the hose attached to it ther seems to be very little / no resistance? My old dad, god bless him if i recall correctly would remind me that it should be hard to suck as its like a bellows / diaphragm in there. ???

I have had the top off the carb and it looks clean in there ( without taking it apart ) I have emptied the float chamber ( i think ) as there is a little hole on the top left, near the edge and near to the non choke venturi that you can stick a straw down and suck the crap out ( not tasty, three strwfuls of petrol )

I have added a video of the symptoms, you can see the engine rev up ( the kncking noise you might here at the beginning is i believe the alternator ) if you do short revs it's fine, but if you open it up and hold the throttle open it goes roarrrrrrrrrrrrrrrrrrrr-stutter-roarrrrrrr-stutter,roar......

now it might be that what i am describing here is, faulty dist, faulty carb and poor fuel pump, but before i take my place in the change that and hope tango your views would be much appreicated.

am off from Tuesday p.m. for about 10 days with no internet access, so if you are kind enough to respond and i don't get back to you i am not ignoring people, just no internet etc etc..

Thanks in advance.



Links to photo's here

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Aidan
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Re: T25-Engine Misfire-Pierburg carb connections, Distributor ?

Post by Aidan »

sounds like faulty vacuum advance, with the engine off and the cap off the disi and the dust shield and rotor off if you suck on the advance unit you should as well as feel the diaphragm resist be able to observe the arm pulling the cam plate in an anticlockwise direction

brucem
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Re: T25-Engine Misfire-Pierburg carb connections, Distributor ?

Post by brucem »

Hi,

thanks for the reply, I think that getiting little or no resistance is probably one of the issues.

Also interstingly enough with intensive googlin last night i came across some PDF service manuals and in one of them there is a picture showing the hose layout to be like this.

Image

This is not the way mine is setup, ( which i suspected was wrong ) so am going to go for new V.A.U. and re connect hoses as shown.

On a similar note if anyone would like copies of the PDF please shout :-)
Carb connection and offical service manual.

Is there a place on here where we can dump fixed files ??

Cheers

B....

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kevtherev
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Re: T25-Engine Misfire-Pierburg carb connections, Distributor ?

Post by kevtherev »

Once the vacuum is sorted out
Turn your attention to the fuel pump and it's ability to deliver fuel to the carb when the engine is demanding more.
AGG 2.0L 8V. (Golf GTi MkIII)

brucem
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Solved

Post by brucem »

Hello there.

I have finally got around to sorting this out !

The problem was a dodgy fuel pipe and connections.

Having been thru the timing, new fuel pump, carb clean out, it turns out that the culprit was the fuel pipe / lack of fuel getting thru. This was found out more by luck than judgement. I happened to be discussing with a friend of mine who offered to have a look at the van, he tinkers ( well he's rebuilding an austin 7 from scratch ). When we opened the engine compartment we found too things

1. the fuel pipe was crushed slightly at a join thus keeping the fuel flow restricted to the carb
2. When he looked at the fuel pipe he commented that it looked way to small a diameter for what he expected the required flow to be.

So off came the old pipe ( a thin plastic thing ) and on went a decent size metal fuel pipe

Fired it up and off we went, runs a treat.

Looks like one of the previous 500 owners had made a bit of a bodge putting a wrong bit of pipe on.

Naturally i assumed ( foool ) that the pipe was the right type / diameter !!1 [Grrrr]

So if you have this problem then this might be one of the things to check.

Thanks for the responses

B....

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