Club 80-90 Forums

Hi I am having a nightmare saga. I have a T25 petrol and LPG 1984 engine in a 1989 van. She had the MOT done a few weeks ago and has been in and out the garage since. Before she went in she was driving well and had been for some time apart from some back firing when she went down hill that had recently started. She failed the MOT on emissions - high CO 5.265/ anti roll bar link bushes / nearside track rod end boot. This work was done along with brake pads which were an advisory. I got her back and drove about 75 miles to Taunton ( I had her on LPG) on the way there she was still back firing and this was getting much worse and the driving performance was very poor. I got back and parked at the local shop she them would not start on either LPG or petrol. I left her over night managed to start her with difficultly but the van was revving furiously as I drove and on idle. I took her back to the garage and they changed the throttle cable and welded the exhaust that had loosened from a bracket. I picked her up and tried to drive to the next town ( on LPG) she was sluggish and the engine seemed to be resisting at times as I started to drive up a long upward slowing bit of road she started to loose power at the roundabout she cut out and again wouldn't start and she has had to be towed back. The mechanics don't seem to know what the problem is all they can tell me is that she is firing but not starting. Can anyone suggest what has happened and what to do now.

Back fire down hill and powerloss is a classic air leak problem on the inlet side
usual suspect is the choke pull down but make sure that all the other reasons are ok.
also note...
A cleaned carb would help
A new fuel filter would help
a good working fuel pump
get it working on petrol and the lpg issues will disappear with it

no big issues just a frustrating elimination process ahead.

on the issue with the fast idle.
normal choke and idle operation...
the autochoke and fast idle mechanism are linked.
Correct start procedure for a cold engine is to depress the accelerator once and release
turn the key and crank.
the engine will idle at 2000 rpm.
when you touch the accelerator pedal again the idle speed should drop to around 1500 rpm, then 1200 then 950 as the motor warms.
The choke is fully off in around 6-8 mins.

I think your cable may have stuck.
These old ladies will have some issues as they reach their later years.
You are there to administer the HRT

Thank you Kev
I had a similar thing happen a few years ago after a fuel pump was changed and an mot was done. This seems like a similar thing, I will head out to the garage today, it is my local garage and only one mechanic likes the vans and he has not been working on it. I will check the choke pull down and electrics myself today. If I can get her started I will book her in and drive north to the garage that does my gas as it does the T25's and she drives really well after a visit there. I'm in a rural part of Dorset and have struggled to find a T25 garage/ mechanic that also does or wants to work on a van with LPG. The garage I am using sells the gas but doesn't have a mechanic trained to work on it. The tend to blame every problem on the gas. I am reassured, last time this happened she was off the road for four months! before a mobile mechanic got her going again. Is there anyone in Dorset who could help if my efforts today fail...........

It is frustrating when a member is so far away and has no reliable mechanic available nearby.

Was it backfiring during normal driving, or just when slowing down ? (if when slowing down usually means a leak in the exhaust, but that would not cause your other symptoms) From what you say (lack of power etc) I guess not just when slowing down.

Backfiring whilst motoring along on a flat road can (as Kev says) be caused by an air leak somewhere in the inlet side. The brake servo hose from the top left side of the inlet manifold is a common suspect. Or carb base gaskets. Or the thin vac hoses on the carb. Or fuel starvation perhaps.

Backfiring whilst motoring along on a flat road accompanied by power loss, then non starting, could also be an intermittent issue with the connections to and from the coil, or the connections on both the dizzy or the ignition amp. Or the ignition amp could be failing = not unheard of at all (I carry a spare one).

Oh dear, as I write this it becomes apparent that any half decent mechanic would just methodically go through the "likely suspects" starting with the most obvious and working back. Hope you can find such a guy. Try Googling "classic car garage" in your area perhaps ?

Don't know if this is too far away from you - but they may know/recommend someone closer to you?
from the wiki -

West Country
Devon
(Dave ) Futbus Ltd. take on a wide range of T25/T3/Syncro specific work and have a very good understanding of the vehicles.
They produce a wide range of custom parts and engineered solutions, for all T25s as well as their particular Syncro interests
One speciality is brake kits, for T2s as well as T3s
If you require references or sight of previous work, take a look at their website or email and just ask :-
Contact Details:
Futbus Limited
07866 581136
http://www.futbus.com" onclick="window.open(this.href);return false;
247engineering@googlemail.com

Hi
The mechanic who knows the van and likes T25's has started to look at her himself yesterday, they believe the electric fuel pump she had fitted was not working. Though I was driving on LPG when she lost power and stopped. The back firing was happening when I drove down hill. I am going to leave them to work on it now since this mechanic has always got her working well, it seems rude to go down now and start interfering. Thank you all for your advice I have taken note and will check these first if the new pump has no effect.

daphne wrote:Hi
The mechanic who knows the van and likes T25's has started to look at her himself yesterday, they believe the electric fuel pump she had fitted was not working. Though I was driving on LPG when she lost power and stopped. The back firing was happening when I drove down hill. I am going to leave them to work on it now since this mechanic has always got her working well, it seems rude to go down now and start interfering. Thank you all for your advice I have taken note and will check these first if the new pump has no effect.

Not rude to say that you have asked a few questions on an enthusiasts forum... everyone does these days
print out the page with the answers and ask him to take a look if he wishes to.


or invite him here and we can discuss % payments for information

Daphne...

just a thing worth mentioning.....there are a number of fuses for the lpg system. I have experienced driving and parking on lpg....and no restart. Turned out to be an electrical issue...If I remember correctly a fuse had blown somehow. Maybe connected with the failure of the electric fuel pump? Electric pump shouldn't be running while on LPG. should only come live when called for by the switch..


oh - the gas controller switch isn't at fault is it? properly connected??

regards

daphne wrote: The back firing was happening when I drove down hill.

9 times out of 10 = a leak in the exhaust system.

Hi
Thank you all for advice 'Daphne the van' is now working on both LPG and petrol, she is driving well at all speeds, not loosing power and has stopped back firing. The electric fuel pump has been changed and some wiring work has been done under the dash. I'm not sure what other work has been done as I had to pick her up this morning when only the showroom is open, not the workshop. The exhaust was mended last week along with the throttle. Altogether a very expensive episode but she is now driving again and I can get back to work, I need to after this. Is there anything I may have done that could lead to the pump failing, I don't want to kill this one.

ghost123uk wrote:

daphne wrote: The back firing was happening when I drove down hill.

9 times out of 10 = a leak in the exhaust system.

I disagree..backfires on overrun are very common with a lean-running VW engine...
http://www.vw-resource.com/backfiring.html" onclick="window.open(this.href);return false;

I run an electric fuel pump and lpg. I agree with previous post that it's wise not to have power to the pump when on lpg and hopefully the pump is near the fuel tank rather than in the engine bay. My pump likes to push rather than pull fuel. I hope the garage have not inadvertently 'created' or added to problems by not knowing their way..... I'm sure in the old days men with carts would blame cars and petrol as devil's work. Seems that lpg can attract this sort of ignorance at times. I hope the garage can explain clearly what was wrong in clear English.

The electric pump has been sited near the original pump at the front of the engine. A different mechanic put it on three years ago, so they have replaced the new one in much the same position. Is this going to be a problem. It has always my belief that this only comes on when I switch from LPG to middle/ petrol position on the little controller. I have suggested an air leak problem to the garage but they told me they did not believe this was the problem. The position of the electric pump has been seen by an LPG specialist and he did not move it when he was fitting a new fuel economy gadget. Am I heading for further problems or likely for this pump to break as well. Someone has told me that you should always make sure there is a reasonable amount of fuel if you have an electric pump. I tend to drive on the LPG and only switch to petrol is I run out LPG. I usually only have 1/4 tank of petrol at any time as I only use it in a search for LPG. Sometimes I have used up most of the petrol whilst finding a garage to fill up, therefore petrol nearly empty is this a problem with an electric pump. Should I have it on 1/2 tank so it never drops below 1/4 tank. Or for that matter drive it on petrol more often?

re pump
I have only ever seen electric pumps sited near the fuel tank.