Running problem

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Radorocco
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Running problem

Post by Radorocco »

Had a recent rather drawn out saga with a fueling problem. After excessive amounts of faffing about (replaced fuel pump, replaced distributor - don't ask) the fault was traced to a split hose round the intank pump.

SInce then the car has been running reasonably Ok, well OK enough to do a 1287 round trip to Scotland and back!

It does appear to be "holding back" though when not at a reasonable level of throttle and when toodling around town at 30 mph it runs very jerkily at times. at a steady 50 plus etc itseems to run fine.

I know its not a great description of a fault and although I think its a fuelling issue, any suggestions as where to look?

(1.8dx engine)

Cheers
Jeff


The Triumph Twins - 1973 GT6 and 1980 Dolomite 1850HL
The Karmann Krew - 1986 'Rocco GTX, 1995 Corrado 2.0
MGB roadster - the "Dark Side"
mark1gls
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Re: Running problem

Post by mark1gls »

Does the fuel pump start to make more noise when the problem happens?
Could be the lift pump is starting to fail/faulty the main fuel pump has to work harder to get the fuel hence more noise.
Some sort of fuel blockage from the split hose and dirt/grit got into the fuel system?


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
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Radorocco
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Re: Running problem

Post by Radorocco »

No, fuel pumps are both nice and quiet and both recently replaced. I gather the fuel filter was replaced as part of the FAFF !!!


The Triumph Twins - 1973 GT6 and 1980 Dolomite 1850HL
The Karmann Krew - 1986 'Rocco GTX, 1995 Corrado 2.0
MGB roadster - the "Dark Side"
mark1gls
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Re: Running problem

Post by mark1gls »

Just because they are new does not always mean they are working, some of the lift pumps I've bought from e-bay have been poor quality (looks ok from the outside) they have only lasted a couple of years.
Your pumps are nice and quiet so I guess it's not them.
What fuel are you using, super or normal unleaded and have you checked the timing, dissy cap and rotor arm?


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
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Radorocco
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Re: Running problem

Post by Radorocco »

Thanks.

As part of the FAFF I understand a new dizzy was fitted so would think that should be all right (uness the wrong dizzy or summat has been fitted). Recently took the car to Ian's recommended chap in Chelmsford (Alan) who told me that the timing was at 0 deg. which apparently is the setting for the DX engine on normal fuel ( he said there is different timing for super but I can't remember what that was), so I've been using normal rather than unleaded. It does need a fill up so I'll put some super in and see if that makes any difference.


The Triumph Twins - 1973 GT6 and 1980 Dolomite 1850HL
The Karmann Krew - 1986 'Rocco GTX, 1995 Corrado 2.0
MGB roadster - the "Dark Side"
Radorocco
Posts: 118
Joined: Fri Oct 26, 2012 10:46 am
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Location: Harrow, NW London

Re: Running problem

Post by Radorocco »

Filled up with Super but no real difference unfortunately.

Another symptom, if the car is idling and I depress the throttle pedal sharply there's no instant response, it has a kind of splutter and then kicks in after maybe 2 seconds ish.

Cheers
Jeff


The Triumph Twins - 1973 GT6 and 1980 Dolomite 1850HL
The Karmann Krew - 1986 'Rocco GTX, 1995 Corrado 2.0
MGB roadster - the "Dark Side"
mark1gls
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Joined: Thu Apr 02, 2009 9:28 pm
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Re: Running problem

Post by mark1gls »

You do have to adjust the timing to get the best out of super unleaded as your car is set for normal unleaded, I think it's advance 6 degress for super?
I found my car did not run well on normal unleaded as it had a lumpy tick over and was down on power and hesitated and I was using more petrol.
You can set the timing with out a timing gun and using a 13 mm spanner to loosen the dissy and a 7mm spanner to adjust the idle speed, you will also need a quiet road and even better if it's got a slight hill as you need to drive a bit and put the car under load then stop and adjust then drive a bit more etc....

If you mark where the dissy is set at the moment by scratching/punching a line in line with the little cut out on the block if it all goes wrong you can turn the dissy back to where it was and all should be fine.
Get the car warm so go for a drive. Stop the engine loosen the 13mm bolt holding the dissy and check you can turn it anti and clockwise to make sure it's not seized nip up the bolt a little then start the engine, CARFULLY as the rad fan is near loosen the dissy clamp a little and turn the dissy clockwise (I guess about a 3mm from the current mark) you may find the idle speed will rise so you may need to lower the idle speed from the bolt at the back of the throttle body, then tighten up the dissy clamp a little close the bonnet and drive the car listen for a pinking noise when the car is underload eg 4th gear at 25 mph or something like 3rd gear at 20 mph and slowly push the accelerator to the floor and listen with the window open for any noise. If there is no noise pull over and advance the timing a little bit more (turn the dissy a little bit more clockwise) with the engine still running so watch those hot things and your fingers and try driving the car some more as above. As soon as you hear the pinking noise you will need to retard the timing a little (turn dissy anti clockwise) till it stops. When it's all done tighten the dissy camp fully and set/check the idle speed.

The other way is use a timing light or take it back to your garage and get them to do it but make sure it's set up for super unleaded.
Let me know if you need any pictures/more info and any of the above.


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
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GTXTRA
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Re: Running problem

Post by GTXTRA »

Can re-inforce Marks point - the DX along with the EG 1588cc GTI engine will run at its best on higher octance fuel/suitably adjusted timing.

Ians old mechanic does know his stuff for sure based on my chats with Ian and Peter but if you're still not sure do take it to someone who lives and breathes these things.

People on here know how much I rate Tim at the Phirm - Edwin from Holland who was at the National can vouch for this after his recent visit during his UK holiday where his Scala was running badly.

A quick run 'round the M25 from where you are down to the Phirm in their new workshop at Blackwater is welll worth thinking about - mention me, ask for Tim to do an initial full vehicle check (standard down there and free of charge excluding any major parts/labour needed), explain the running issues and ask him to 'set up' the thing up.


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PeteGLi
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Re: Running problem

Post by PeteGLi »

I run my '87 DX on normal unleaded - 95 RON - with the timing at 6 deg BTDC, with no problems at all. Idles and accelerates beautifully.


Radorocco
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Re: Running problem

Post by Radorocco »

Thanks for all your help.

As it turns out this should really have been in the electrical section :oops:

Started the engine and was just looking for anything obvious and noticed some sparking where an ignition lead connects to the dizzy cap. New set of leads and now running sweet as.

Yay!!!

Happy Jeff


The Triumph Twins - 1973 GT6 and 1980 Dolomite 1850HL
The Karmann Krew - 1986 'Rocco GTX, 1995 Corrado 2.0
MGB roadster - the "Dark Side"
mark1gls
Posts: 3957
Joined: Thu Apr 02, 2009 9:28 pm
fill in the right answer: 10
Location: Somerset

Re: Running problem

Post by mark1gls »

Glad it's sorted out now.


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323
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