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Petrol engine cutting out when hot

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Category: LT, Crafter & Sprinter Section
Forum Name: LT, Crafter & Sprinter Tech
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URL: http://www.brick-yard.co.uk/forum/forum_posts.asp?TID=85944
Printed Date: 28 Mar 24 at 22:13
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Topic: Petrol engine cutting out when hot
Posted By: Angelina
Subject: Petrol engine cutting out when hot
Date Posted: 09 Aug 14 at 15:07
Hello all, I'd be grateful for any thoughts on this new issue I'm having with my horsebox.

It's a 1982 LT35 2.0l petrol engine. 

I was driving home the other day when the engine sort of paused or spluttered, it felt as if I was running out of petrol. I was going along quite fast (well, 50 mph) and I slowed right down and managed to get home without completely stopping. 
I booked in with a local garage as the fuel tank was pretty rough and I thought maybe there were bits of rust getting in to carb, bought and had fitted new fuel tank and garage took for mot. Flew through mot but on way home they had same issue only with them the engine completely cut out, they got it home, blew out the carb with an airline, adjusted the timing, and gave it back to me. 
So, driving back from garage had to follow a diversion as road was closed and after about 20 mins, same thing happened. 

Talking to farmer where I keep the horsebox, he said he wondered if it was overheating, and fuel can evaporate in the carb which is why it feels like it's running out of petrol. 
The temperature gauge is on about a quarter, no light flashing, but I did notice that the engine cover was really hot, don't know if that's normal? 

Any thoughts and/or things to try much appreciated. I've got a new coil sitting here in a box, is that worth putting on? Anything else?
Thanks in advance



Replies:
Posted By: LTCamper89
Date Posted: 09 Aug 14 at 15:22
I would say starvation possibly due to a blocked vent. Changing the fuel tank was probably a bit premature since the old vents back on, without making sure they were clear may be the problem.

AndyT may be along, he has an early petrol model too. Plenty other will no doubt put a word in.


-------------
1989 LT28 2.4D    Saviour of 6Music, well one of them. Now playing http://www.bbc.co.uk/radio/player/bbc_6music

VW LT Camper not Cramper

....at least the roof is not rusting away....


Posted By: Angelina
Date Posted: 09 Aug 14 at 15:29
Thanks, where are the vents and how do I check them? Old tank needed changing really, was full of holes and mainly held together with milliput! 


Posted By: LTCamper89
Date Posted: 09 Aug 14 at 15:47
Just found this page, in German, but the trnslation is easy enough to follow. It may give you a place to start.
http://www.lt1-forum.de/dokuwiki/doku.php?id=start:reparaturtips:tank" rel="nofollow - http://www.lt1-forum.de/dokuwiki/doku.php?id=start:reparaturtips:tank

Milliput is one of AndyTs' handy repair tips, so be careful.Wink


-------------
1989 LT28 2.4D    Saviour of 6Music, well one of them. Now playing http://www.bbc.co.uk/radio/player/bbc_6music

VW LT Camper not Cramper

....at least the roof is not rusting away....


Posted By: Angelina
Date Posted: 09 Aug 14 at 15:53
Lol, I know, it was him that put me on to it- great stuff and I've converted the farmer to it when repairing some of his machines! But there comes a point, when it's leaking everywhere that I thought was worth replacing the tank. New tank is lovely and shiny!

Thanks for the link :)



Posted By: volition82
Date Posted: 10 Aug 14 at 07:25
When it happened the second time with you were you also going fast (ignoring the fact that fast and LT is an oxymoron ) or under load i.e a lower gear up a hill? If so could possibly be the fuel pump breaking down when under to much load or after being run for a while.

With reference to the coil, do you have a Haynes manual and a multimeter? If so they are easy to check and the manual shows the range you should be getting.

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1989 LT35 - 2.4 Lpg/Petrol - Converted To Camper


Posted By: Angelina
Date Posted: 10 Aug 14 at 09:06
I was in low gear but around the lanes so slow. I may have been gently accelerating..... 
If the temperature gauge moves does that mean it works? The fuel gauge doesn't work.
Someone said drive it without the cap on the coolant, is this a good or bad idea?!
I've put the new coil on anyway as I had one and it's a 5 minute job, not test driven it yet to see if any change


Posted By: AndyT
Date Posted: 10 Aug 14 at 14:44
Coil would have been my starting point as they do break down and heat up.
Not easy to check on an LT cos of the engine cover.

There are a couple more simple checks but since you've replaced it let us know how you get on.

Edit: Great news on the MOT btw, emmisions were fine so this makes me think it's a spark issue.



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LT28 1979 2.0 Pampas Nevada Camper LPG 93K, 1980 T3 A/C Camper 98K,1994 RRC 3.9 LPG 120k , 1998 Audi A6 Est 2.5 V6 diesel 127k



Posted By: Angelina
Date Posted: 10 Aug 14 at 17:28
Just took it for a test drive with new coil and now feels different. Backfired and running really rough. Feels like it did when timing needed adjusting. Confused!


Posted By: AndyT
Date Posted: 10 Aug 14 at 18:32
Assuming the new coil is the correct 1 and wires are on the correct side, doesn't make much sense.
Is the dizzy lose by any chance and has been disturbed, and are the points sparking when it turns over. Points could have been adjusted to make it run with the old coil.

Bit of trial and error here but we will get there.


-------------
LT28 1979 2.0 Pampas Nevada Camper LPG 93K, 1980 T3 A/C Camper 98K,1994 RRC 3.9 LPG 120k , 1998 Audi A6 Est 2.5 V6 diesel 127k



Posted By: Angelina
Date Posted: 10 Aug 14 at 21:32
I just copied where the wires were on the old coil, it's not the same make but was sent to me as the right one... could the timing need to be set different for different coils? (Or should I buy a new coil same make as old?)
The dizzy has an electronic conversion, could the dizzy itself be worn?
Farmer has told me to run engine with hose pipe running in to expansion tank to flush radiator through, is this safe to do?!
Thanks for your help :)


Posted By: LTCamper89
Date Posted: 10 Aug 14 at 22:27
What AndyT meant about the timing being set for the old coil, is if they decided it was rough it may have been advanced/retarded to suit the condition of the coil, and therefore helped it run a little better.

Distributors do wear, especially after thirty years, and that will make a difference to the pickups and timing, with electronic ignition. Points tend to be more accurate since EI does not necessarily follow the correct advance curve.

?Do they have a condenser? Old bike stuff, so may not be applicable.

Getting there.Thumbs Up

Never done the hosepipe trick, so would not like to comment.


-------------
1989 LT28 2.4D    Saviour of 6Music, well one of them. Now playing http://www.bbc.co.uk/radio/player/bbc_6music

VW LT Camper not Cramper

....at least the roof is not rusting away....


Posted By: mat_the_cat
Date Posted: 11 Aug 14 at 00:18
Flushing the radiator through with a hosepipe MAY clean out any deposits in there and help the engine run cooler. But it would only help your cutting out IF it was overheating (which the gauge suggest it is not) and IF the overheating was the cause of the problem. There are probably better things you could spend your time on! (And there would be no need to have the engine running to flush the radiator).

The cause may well be heat related, but not necessarily overheating if you see what I mean. It's obviously difficult to diagnose blind, and now you seem to have a second problem too!

"Feels like it did when timing needed adjusting"
The fact you've had the timing adjusted, and now it seems like it has changed again, makes me wonder if you do have a fault in the distributor. Maybe a broken advance weight spring perhaps, allowing the baseplate the points are on to move around?

FWIW, intermittent coil problems I've come across have been worse under load so gut feeling says the coil may be OK. Might be worth sticking the old one back on to see whether the backfiring and rough running stop, but I can't see how changing the coil alone would cause that.

The initial problem *may* be fuel vaporisation. Modern petrol is more volatile than it used to be, so solder vehicles are more prone to this even if everything is A1. If you were moving slowly, there would be little fuel being pumped so consequently it's sat in the hot engine bay for longer. The engine bay will be that little bit warmer as there is less cooling airflow, so that may cause the fuel to vaporise and not be pumped by the fuel pump, especially if the original pump is getting tired.

IF this is the problem it could be helped by re-routing fuel pipes, and/or fitting a fuel return line if there isn't one as standard, or fitting an electric pump near the tank. This puts the fuel under pressure rather than trying to suck it, which makes vaporisation problems worse.


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Mid engined, 6 cylinder, turbocharged 2 seater - it can only be a VW LT!


Posted By: AndyT
Date Posted: 11 Aug 14 at 03:07
This is a bit difficult without being able to check what the timing is set to etc, but regardless of the setting the garage had it running for a bit before problems re-occurred.
LT's are really simple so it can only be spark or fuel.

Don't go spending lots of money on a new dizzy etc until we have done a few checks.
Ignore rad for now.

What I'd like to do is start it from cold and see what happens as it warms up.

As suggested I'd put the old coil back on for now. Only seen it once but the coil I bought for the RR had connections reversed. Unlikely but worth checking.
Also check that all the connections are in good condition.

Air getting into fuel lines:-

Fuel pump is in the tank and the connections are on the top so you can't check those, but you can check that all the other clips on the fuel pipes are tight and none of the pipes are split or look old.
Hopefully garage changed them all when they fitted the tank.

Engine bay:-

Undo clip and remove the air intake from top of carb.
Depending on carb there will be a wire for either the auto choke or fuel cut off.
Check that it is connected and in good condition.
Years ago the fuel shut off valve on mine came lose and caused all sorts of problems as it let air in.
Check that the nuts holding the carb on are tight.

Have a look in the top of the carb and check that the choke flap is closed. It should gradually open as the engine warms up.

See if it starts and if so leave it running (Choke will be on) just rev it occasionally and note how it runs (any backfiring, spluttering etc). If there are problems fit a new condenser (£7 ish) and try again.

Once the engine is up to temp choke should be off (check that choke flap is open), how does it run now. With the engine cover off heat should not cause fuel vapourisation.

If it's running ok, cover back on and take for a test drive.

If it's not and you have checked everything let us know.



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LT28 1979 2.0 Pampas Nevada Camper LPG 93K, 1980 T3 A/C Camper 98K,1994 RRC 3.9 LPG 120k , 1998 Audi A6 Est 2.5 V6 diesel 127k



Posted By: Angelina
Date Posted: 11 Aug 14 at 06:07
Ok thanks everyone, will get to work and report back.

Andy mentioning air intake reminded me the the garage man said he took it off to get through emissions for mot..?
Don't know why they adjusted timing, they said they don't have a strobe so did it by ear, it had been running really well for last 2 years since tune up man did it.
Thanks again
I did ask them to change all hoses when they did tank so hopefully they did! But will check


Posted By: mat_the_cat
Date Posted: 11 Aug 14 at 07:54
Good advice there Andy. I had assumed the pump was an engine driven one, so the fact it's in the tank makes vapourisation less likely.
Originally posted by AndyT AndyT wrote:

Don't go spending lots of money on a new dizzy etc until we have done a few checks.

Agreed - I hope I didn't come across as suggesting you should buy one on the basis of a blind guess!


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Mid engined, 6 cylinder, turbocharged 2 seater - it can only be a VW LT!


Posted By: AndyT
Date Posted: 11 Aug 14 at 08:25
No mate you didn't but I've seen too many people fitting new parts in desperation, when a few simple checks are all they need.

Timing will probably need looking at, should be 5deg btdc @900rpm and at the same time mechanical and vac advance checking. 10mins with a strobe light. Can post up details if needed.

As regards mot and air intake, could be a dirty air filter or fumes from breather.
If its the latter disconnect before MOT, plug back in afterwards.
Old 4 pots are pretty bullet proof but they do have to work hard in the LT.

At the moment my favourites are the condenser and the king lead, both are cheap to replace.


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LT28 1979 2.0 Pampas Nevada Camper LPG 93K, 1980 T3 A/C Camper 98K,1994 RRC 3.9 LPG 120k , 1998 Audi A6 Est 2.5 V6 diesel 127k



Posted By: Angelina
Date Posted: 11 Aug 14 at 11:53
Do I have a condenser as my points have been converted to electronic?


Posted By: Angelina
Date Posted: 11 Aug 14 at 11:56
Had a look at pipes going to and from tank, all new and tight on there, looked at air filter which is clean, will do some more later, was short of time this morning.

My carb is a pierburg 1b1 and it has a manual choke.

Thanks again.


Posted By: AndyT
Date Posted: 11 Aug 14 at 15:25
I think you will still have a condenser but can't be certain as I've never fitted a conversion.
It's a metal cylinder shape attached to the side of the dizzy.

Sounds like your carb has been converted to manual choke at some point so I can't say if it has a shut off valve. If there isn't a wire leading to the carb Just have a look around to see if there is a bare spade terminal anywhere. I'll try and look up the carb to see.

Principle is the same though, check that when you pull the choke on the flap closes in the carb, and when choke is off the flap is wide open.


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LT28 1979 2.0 Pampas Nevada Camper LPG 93K, 1980 T3 A/C Camper 98K,1994 RRC 3.9 LPG 120k , 1998 Audi A6 Est 2.5 V6 diesel 127k



Posted By: Angelina
Date Posted: 11 Aug 14 at 18:44
All pipes to/from fuel tank are new and tight on, carb isn't loose, the flap in carb opens and closes as I pull the choke in and out.

Had a look and there's no condenser on the dizzy.

The farmer took pity on me tonight while I was staring in to the carb forlornly and offered to take it for a drive to see what he thought- being more mechanically minded than me he is more clear about what is actually happening. 
He said it's actually just cutting out suddenly, but as I'm driving along when it does it, it bump starts it'self with the momentum which is why I feel like it's spluttering and kangerooing along.

When he got back it did it while it was idling and it just stops but will restart again straight away.
He said it's not misfiring and he thinks it must be electrical but not sure what. He did notice the coil is very hot, he didn't know if that is ok? 

Thanks again, thoughts much appreciated.  


Posted By: AndyT
Date Posted: 11 Aug 14 at 19:02
Coil should not be really hot, it's a sign of it breaking down.
I'd dbl check that the one you bought is the right coil, needs to be a ballast resistor type.
Also worth replacing the king lead (top of dizzy to coil) only £5 tops.

If that doesn't work I'd suspect the electronic module on the dizzy, they do break down, had to replace mine on the RR.
Since you don't have access to a strobe and multimeter it might be worth calling the tuning guy.
If it is the module they are not too expensive £35 ish.

Don't know the model you have fitted but there are quite a few suppliers eg:-

http://www.simonbbc.com/electronic-ignition-kits" rel="nofollow - http://www.simonbbc.com/electronic-ignition-kits

If you have any questions etc please ask.


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LT28 1979 2.0 Pampas Nevada Camper LPG 93K, 1980 T3 A/C Camper 98K,1994 RRC 3.9 LPG 120k , 1998 Audi A6 Est 2.5 V6 diesel 127k



Posted By: LTCamper89
Date Posted: 11 Aug 14 at 19:11
!! http://www.simonbbc.com/bundle-deals/points-set-cap-rotor-arm/vw-bosch-1-pcs-right-hand-points-rotor-arm-distributor-cap" rel="nofollow - A full points setup, cap, arm, points and condenser, for less than a tenner !!!..if it is the right one.

Proper bargain, and worth having in the toolbox.




-------------
1989 LT28 2.4D    Saviour of 6Music, well one of them. Now playing http://www.bbc.co.uk/radio/player/bbc_6music

VW LT Camper not Cramper

....at least the roof is not rusting away....


Posted By: Angelina
Date Posted: 11 Aug 14 at 19:20
Thanks, it's the new coil that's hot, (as was the old one)  it's definitely a ballast resistor, has that written on it. Wonder why the coil is getting hot?

I can't find just one lead to buy online, seems to be sets, if anyone could point me in the right direction? 

Will try the lead and give tune up man a call. Thanks


Posted By: jason k
Date Posted: 11 Aug 14 at 19:43
Check the rotor arm for cracks too!

-------------
Bcs shallowest surf award winner 2006
camperjam 2011 chug and tug team member
aberdare. south wales
newest member of karmann korner
no longer the only moderator to manage to ban himself





Posted By: volition82
Date Posted: 11 Aug 14 at 19:50
If it doesn't turn out to be the coil might be worth checking the wiring on the back of the ignition. If you have a dodgy connection it could cause it to just cut out like that.

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1989 LT35 - 2.4 Lpg/Petrol - Converted To Camper


Posted By: AndyT
Date Posted: 11 Aug 14 at 21:02
You can get a lead from any local car accesories, there's nothing special about them just need to be long enough. Take yours with you and they should have no problems matching it.

LTCampers bargain is just that even with £4 delivery on top.
Might be an option if the ignition module is suspect, go back to basics.

No idea why the coil is getting hot when new, but I'll do  a bit of googling.


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LT28 1979 2.0 Pampas Nevada Camper LPG 93K, 1980 T3 A/C Camper 98K,1994 RRC 3.9 LPG 120k , 1998 Audi A6 Est 2.5 V6 diesel 127k



Posted By: Angelina
Date Posted: 13 Aug 14 at 10:10
Tried it with a new lead this morning and same problem still, it only does it when warm but cuts out completely, but will restart immediately. 
Am I now looking at new parts in dizzy or new dizzy? Going to give the place a call in Andy's link, see how much I'm looking at for parts. Do I try new rotar arm and cap first? 
Desperate to get it going again, I need to use it for 2 days in a couple of weeks which will cost me £100 per day in lorry hire, so I'd rather spend the money sorting mine!
Thanks


Posted By: Angelina
Date Posted: 13 Aug 14 at 12:24
Hmmm been googling "why is my coil getting hot" and I'm wondering if that is my problem? If the coil being so hot is causing the engine to cut out? Going to go for a drive with my spare coil, wait for it to cut out and try putting new coil on; although if this works, I have no idea how to rectify it! 


Posted By: AndyT
Date Posted: 13 Aug 14 at 14:27
I think we have done everything we can without a multimeter and strobe.
With both you can test the dizzy, the coil and all the wiring etc that goes with it.
Could be a loose connection somewhere or the ignition module, or the alternator supplying too many volts to the coil for example.
You have had 2 years trouble free running since you called the mobile guy out, I really would call him again before you fit any new parts.


-------------
LT28 1979 2.0 Pampas Nevada Camper LPG 93K, 1980 T3 A/C Camper 98K,1994 RRC 3.9 LPG 120k , 1998 Audi A6 Est 2.5 V6 diesel 127k



Posted By: Angelina
Date Posted: 13 Aug 14 at 15:04
Yes you are right, thanks Andy. I will give him a call :)


Posted By: AndyT
Date Posted: 13 Aug 14 at 16:39
Good luck, and if you do need to find parts etc let us know.
Below is the detailed info for testing the dizzy:-

Dwell angle 44deg -50deg

Dynamic Timing 5deg BTDC at 850-950rpm.

Centrifugal advance:-
Commences 1100-1500rpm
12deg to 16deg @2400rpm
23deg to 27deg @3400rpm
Maximum 32deg to 36deg @4200rpm

Vacuum advance:-
Commences 100mm Hg
Maximum 17deg to 21deg 310mm Hg


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LT28 1979 2.0 Pampas Nevada Camper LPG 93K, 1980 T3 A/C Camper 98K,1994 RRC 3.9 LPG 120k , 1998 Audi A6 Est 2.5 V6 diesel 127k



Posted By: Angelina
Date Posted: 14 Aug 14 at 05:56
Thanks Andy, will print off and have with me when tune up man comes.


Posted By: Angelina
Date Posted: 22 Dec 14 at 13:08
Hello everyone, I thought I would come back to update this thread in case anyone else has same issues.
Got tune up man out who said it's definately an issue with the distributor. I ordered and fitted a new electronic conversion kit to the dizzy and it's all fixed now- had to get a different coil, a non ballast resist, as it doesn't have a condenser and points any more.

I'm hoping for a few more years of trouble free motoring from the old girl now!

Thanks for all your help :) 



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