Car dies under any load, limpt home on choke 2nd gear! Help please.

[88turboesprit]

Hi All,

 

I am not having much luck with my Lotus. Since taking ownership a few short
weeks ago I have had to repair the light module, Also to Remove and fix a fuel tank now I have a problem.
 

After relocating the fixed fuel tank I started the car and all was well I drove it 2 miles and put my
foot down a little. The car went then spluttered to a halt. As soon as I put my
foor on the throttle it dies. But only under load not in neutral.

I drove it home on the choke but as soon as
I touched the throttle it dies. I limpt back in 1st and 2nd (it couldn't cope
with 3rd).

So as the tank was rusty I thought it must be a blocked fuel filter. It was very dirty and rusty fuel that
drained out and I fired up the pump to see if it was working a steady flow of
fuel came arching out about 6-8 inches.

I drained the fuel from the sump and flushed a couple of times,
it was full of little bits in the bottom. I replaced the filter and drove it up
the road. It ran of for 300 yards ok and then started all over again, cutting
out on the throttle. so choke out and limp back. It ticks over fine.

I had noticed that the water level was low as it drained abit when i did the fuel tank. I wondered it the turbo has not been cooled (there is a bit of water in the bottom of the header canister) and this
might be causing it.

I also didn't find where the black and white vacuum pipe went to and it appeared to just vent to
air even though it had a tee peice at its end. Where is this meant to go anyone? I saw a picture that showed it going to just before the one way valve afetr the carbs but there is no break in the pipe there on mine.
Could this black/white pipe be causing it?


Any ideas where to start next would be great. Why did it run fine
for a few hundred yards? I cant believe the new fuel filter would be blocked
that quick as i flushed and it was pretty clean by then.

Thanks
Tony

Edited February 16, 2013 by 88turboesprit

[andydclements]

Have you checked the carbs to ensure that no debris got through to them? It could be in the float chamber but more likely a small piece blocking a jet. 

[88turboesprit]

thanks for that Andy. I would have thought it would run but rough acceleration if A jet was blocked. I haven't checked but did wonder if it could be that. I don't really understand why it would run for a short while fine. But can I just unscew the jets in the carbs and check or access the float chamber to check for debris. It

 

Why does it run on choke all be it just to limp home in 1st or second but not on throttle anything other than 2mm open?

 

What pressue should there be in the fuel line?  As it might be a clogged regulator?

 

Thanks for your help.

Edited February 16, 2013 by 88turboesprit

[andydclements]

You can remove the tops of the carbs quite easily, 4 machine screws each carb. The jets can also be easily then accessed as they are secured in place by being screwed into the body of the carb, so no settings to worry about upsetting.

 

If a jet is blocked/ partially blocked, as you open up the throttle you'll be increasing the air going to the engine but not the fuel and so weakening the mixture until it finally gives up.

 

As you say it could be the regulator but I don't have the pressure spec to hand (my car has the later fuel injection turbo engine).

[Sparky]

Does sound like fuel delivery, and it won't be helped by a vacuum issue.  Pressure from the regulator should be close to 4PSI.  I wouldn't consider the turbo at this point as it wouldn't compromise normal running.

 

Did it drive fine when you bought it?

[andydclements]

Ah, by black and white pipe I hadn't considered it might be part of a vacuum system. 

Can you post a picture of the carbs etc as I'm struggling to recall the vacuum pipes on the Turbo cars.

 

I just did a quick Google search, the image may help show the layout, it looks like a UK spec car.

http://i421.photobucket.com/albums/pp296/sweetesprit/DSCF8192.jpg

[J400GED]

Tony,

      The black hose with the white trace should be connected between the TIV and the vacuum advance capsule. See attached sheet for details.

 

Hope this helps

 

Ged

Vacuum Hoses.doc

[Mike6]

There are a few black and white vacuum pipes if they are original and your car is the carb turbo. The first one runs from the boost guage transducer, under the wheel arch along to a Tpiece which then goes to the one way valve and then into the cold enrichment valve. The other one goes from the thermal ignition valve into the throttle jack solenoid.

 

To be honest I dont think a problem with the vacuum pipes would cause the issue you have. If you are loosing boost then yes.

 

If the car was running fine before you carried out some repairs then the problem must lie in that area or you have dislodged some connectors. Was it the right hand tank you took out . A lot of plumbing runs in that area and that is the first place I would check.

 

If ypu pm me your email I could scan you a copy of the vacuum connection diagram 

[88turboesprit]

Yes Gary it drove fine on the 250 mile trip home. I have a good picture of the vacuum system but don't know how to attach to the forum. but the picture is in this post:-

 

http://www.thelotusforums.com/forums/topic/33693-88-turbo-carbys-no-power-over-3000-revs/

 

The black and white is at the top. But i don't remember disconnecting this and am sure that it was just laying there with on 2 open ens of a t-peice at its end! though age may have played a part. As you can see in the pic that it should tee into the pipe leading to the one way valve, but mine is connected without  this pipe and I definatly didnt touch this area.  

 

Fuel at 4psi doesn't sound like alot as I thought there was some rule about turbo pressure plus about 3 psi (I read this somewhere and might be rubbish!).

 

I may have made a hash of connecting the vacuum pipes but if so why did it run ok for 1 mile or so? Surely I would have noticed as soon as I left the drive (It did only fail once I put my foot down as the car had warmed up ticking over for 10 mins before I left the drive)

 

I think it will be the fuel pressure as the No 1 suspect, then carb jets or vacuum. It runs on choke but add any air and it just dies not matter how little you tickle the throttle.

 

On this post they ask if the choke makes it better but dont explain why as this problem the choke made it worse unlike mine. What do you think he was getting at?

Thanks again

Thank Mike,

 

I forgot that I actually drove my daughter to school (4 miles round trip) with no problem after I had replaced the petrol tank. Then On the second time I put my foot down and splutter cough had to walk 1/2 mile to her school! I limpt home on tickover and choke.

 

Replaced fuel filter-yuk came out and then flushed tank -more rubbish- so felt sure that the new filter would solve. But 300 yards after the car pulled fine I was back to the same old story of having to use tick over and choke to return home. 

 

If it was vacuum im sure the first 4 mile drive should have not worked. It must be fuel pressure or blockage i think. Should I remove pressure regulator and inspect it?

 

Thanks again all for your great help. I am feeling abit down about this car and its a shame because I loved getting it and hope to sort soon.

[slewthy]

Hi Tony,

Do you have some carb cleaner? If so, get cleaning and spraying out those jets.

My NA had crap in the float chambers so stuff definitely gets past the filter. Does your car also have the filter in the fuel lines leading to the carbs? Check those too if you have them.

 

For that matter, do you know when the car last had its carbs rebuilt? There are kits out there for this and might be an evening exercise worth considering.

 

Best of luck. Dont get downhearted. The feeling you will get when this is sorted will soon drown out these initial disappointments.

 

Simon

[Sparky]

The regulators are pretty bomb-proof.  Providing it's got about 4PSI at idle, I'd first be looking at float level in the carbs.  I'd also consider the fuel pump - maybe some crap got that far?

 

One other thing - how bad was the tank, and how did you fix it?

[88turboesprit]

Cheers Simon, Is there a link on how to check jets and 'float chambers'? As I think this need to be looked at. Possibly I need to rebuild them but first I want to just get it to run a bit.

 

And thanks Gary- I think it is just Tank- pump-filter- fuel regulator and carb in line on mine. So the pump (which appears new) is first to take the rubbish from the tank and this could have damaged it so under load it is failing?

 

I have run the pump disconnected and it pumps a stream of fuel out to about 6" from the end before arking down to the floor with no load. I will try to borrow an inline fuel pressure tester to confirm. I only had this tank repaired and it was quite rusty, having flushed it it seems to be running clear now though. So I would not expect it to foul up new the filter and carbs so quick. There must have been rubbish further up the system than the filter I have replaced. So Regulator first and Carbs are next.

I will keep you posted but meantime if there is a carb check guide you can point me toward or just let me know how to I would be very greatful.

 

Tony

[88turboesprit]

Does anyone know what carbs they are so I can search for a service manual? I think they are dellorto's of some description.

[slewthy]

The guys on here will know the exact type but it will also be stamped/written on the carbs themselves.

I was loaned this book for when I rebuilt mine but there must be others out there.

http://www.ebay.co.uk/itm/How-to-Build-Power-Tune-Weber-Dellorto-DCOE-DCO-SP-DHLA-V275-/200895791179?pt=Non_Fiction&hash=item2ec652804b&_uhb=1

[mdw]

The pic below shows the muck that was in my carbs before rebuilding.  The car had been standing still for 4-5 years.

Edited February 17, 2013 by mdw

[andydclements]

DHL40

[88turboesprit]

Thanks Simon, Andy and Malcolm.

 

I have just flushed tank again loads, now seems clear but did get some more crap out. I checked the new fuel filter and no blockage. Run the fuel pump and put my finger over the end of the pipe and it seems to provide a high pressure flow as it was not possible to stop flow coming out. I thenm replaced everything and drove the car.

 

As before it appeared ok for first few hunded yards until I put my foot half way down and then the problems started again as before. The higher demand brings the fault to the fore and then no matter where my foot is it wont go until i use tick over and choke to limp home!

 

If it was carb jets or floats wouldn't it be unlikely to be quite so drastic a change from fine to not running at all? It seems unl;ikely that all jets would simultaneously block?

 

Thanks

[andydclements]

My suspicion is: The idle jets are separate to the main jets (which normally come into plat at 2000rpm when under load but you'd get much higher revs without them if not under load), so it's not the jets blocking, it's the jets being blocked and so as soon as you open the throttle up the mixture goes so weak so suddenly that it cannot combust.

[Sparky]

On the assumption that it was working before you played with it... ;-)

 

If that pipe is still disconnected, a number of management systems controlled by vacuum won't be working properly, and it's possible that this won't become evident until the engine warms up.  Notably, you'll probably have ignition advance issues.  That has to be first on your list, if only to eliminate it from your enquiries.

[88turboesprit]

SORTED!!!!!!!!!!!!!!

I was playing around looking at the carbs and wondering the best way to remove
float chamber case and touched one of the two large metal joining/balance pipes
and noticed it moved. I then checked the top 19mm bolt and it was loose as were
all the others! I thought I did them up tight enough (they only have paper
washers) but obv. not and they had worked loose. No Fuel leak but must have
leaked to atmosphere causing a lack of pressure in the fuel line.

I tightened them up and woosh!!!!!!! It went great.

Thanks all for your help. A carb service is on the cards in the spring.

BTW It looked like it boosts to about 2/3 of the gauge which would indicate about 10psi is this
about right?

Thanks again All.

Tony

[pete]

thought 8 psi  was max but sure someone more knowledgable will answer soon

[Sparky]

Hehehe!  That was the problem in the thread you linked to in post 9!

 

Glad it's sorted mate.

[Mike6]

Glad its sorted. Funnily enough I was driving to Newlands Corner this morning when my car lost power juddered considerably a few times, backfired and then died rapidly, just couldnt get the revs up and then it cut out. Nearly an hour wait for the breakdown truck and then it fired first time and taking it easy managed to get home.

 

Wondering if its the fuel pump and filter as these are about the only things I havent changed.

[88turboesprit]

Check them pipes Mike! The backfire and dieing sound like fuel to me.

[Shanesprit]

I have similar issues with my 89 2.2 na

No idea what's up yet though I think it's ignition coil maybe,

Problem is it drives well although I know it's rich on tick over

But if I open it up for a short while it starts missing and at first I can open the throttle and drive through the issue

But the longer it goes on the worse it gets, some times won't even tick over

But the tricky part by the time I stop the car it runs fine. So I cannot see the engine when the issue is present?