Help - very sluggish car

kiwi · Post by **kiwi** » Sat Dec 19, 2009 12:45 am

MULLEY wrote:I was until this most recent fill up running on sunflower oil with derv, in a ratio of approx 75% derv to oil. So i dont think thats the problem.

Dollywobbler · Post by **Dollywobbler** » Sat Dec 19, 2009 11:21 am

Have to say, fuel filter is the likely cause. When I ran my Merc 300D on Bio through a cold snap, I had to change filters quite a lot. It was sluggish enough at the best of times so I couldn't hack any fuel supply issues on top of that!

MULLEY · Post by **MULLEY** » Sat Dec 19, 2009 11:30 pm

Changed the fuel filter, no difference. Checked the brakes, thats not the problem either, i'll check the pump arm position against the throttle position tomorrow & will report back.

Something which i've noticed as an example, in 2nd gear, foot welded to the floor, car revs slowly up then at say near the top end of the rev range the car surges forward, change upto 3rd, deadly slow at accelerating again.

If i use lightish throttle & change gear at 2000rpm, the car although not as quick as normal, doesnt seem that bad & can get upto about 60, always seems that whilst under load its really poor.

Does that point towards a knackered pedal box?

Post by **docchevron** » Sun Dec 20, 2009 1:15 am

Has the throttle pedal moved away fromt he brake pedal towards the O/S of the car??

I'd be thinking about checking the cam and pump timing just in case the belt has skipped a tooth..

At this stage I'd also think about undoing the injector pipes off the pump and turning it over to roughly guage how much fuel is actually being passed by the pump.
Could be the stop solonoid is on it's way out I guess, or, just maybe the veg oil has murdered the pump.. since it will, even a bosch pump eventually..

MULLEY · Post by **MULLEY** » Mon Dec 21, 2009 12:36 am

Hmm, interesting thoughts Doc, i'm hoping that your wrong (in a nice way of course).

What would skipping a tooth on the cambelt actually feel like when it happens? Does this affect the idle from cold or hot? The car seems to tick over as normal, & the noise from the engine appears fine. I have managed to get the car upto 100 during my italian tune-up & it seemed fine.

Not sure about the throttle pedal, i think it's in the correct position, how far would it have to have moved?

If the veg oil has killed the pump, wouldnt the pump be leaking fuel & also run as rough as a badger? Neither of which its currently doing.

MULLEY · Post by **MULLEY** » Tue Dec 22, 2009 1:03 pm

I've had a look at the throttle pedal, it does appear to be at slanted angle from left to right with the bottom part closer to the door than the upper part. Should it be dead straight? This could be the cause of the problem

MULLEY · Post by **MULLEY** » Tue Dec 22, 2009 9:46 pm

Yesterday, i put approx 1 litre of petrol in the tank to see if that helped with thinning out the remaining oil to see if that helps at all. Initially it only seemed to make a minor difference on the way to work this morning, but on the drive home the car seemed a fair bit better, still not 100% but a lot better than it was.

I'll keep an eye out for things & report back on here, lets hope its not a bust pedal box afterall

demag · Post by **demag** » Mon Dec 28, 2009 11:04 pm

Have you changed your air filter at all? Could be something simple. You've changed fuel filters recently, a slight air leak will dull the performance under load.

MULLEY · Post by **MULLEY** » Tue Dec 29, 2009 12:07 am

Not changed the air filter, its a K&N so in the summer i removed it & cleaned it, so it won't be that. I've got a suspicion that its a bust pedal box, although no one has commented on my description of the pedal position on my car?

No idea about an air leak, would that affect the idle at all & starting the car up? All of which are fine.

ken newbold · Post by **ken newbold** » Tue Dec 29, 2009 12:20 am

A broken pedal box is the easiest thing to diagnose.

Get your head down in the footwell with a decent torch. Have a look and feel if need be, where the right angle bend is on the back of the pedal box, on the right hand side where the accelerator pedal is bolted through it.

If nothing is visible, try moving the pedal from right to left and keep looking and feeling for cracks or "give" in the metal.

BX596 · Post by **BX596** » Tue Dec 29, 2009 8:05 am

I had similar symptoms and mine was the pedal box.If you get your old one welded up,tell the welder man not to weld around the hole.I had to get my trusty angle grinder out,when I got mine back

kiwi · Post by **kiwi** » Tue Dec 29, 2009 10:34 am

I got a spare and am thinking of putting it in the TRS. The accelerator pedal is a little bit offset in that car basically you can put your foot between the brake pedal and the Accelerator pedal.

Does not cause any problems though its not flopping around just bent to the right.

Post by **Tim Leech** » Tue Dec 29, 2009 10:48 am

Mulley, get the missus (with the engine off) to sit in the car and press the throttle down as far as you can, stick your head under the bonnet and see whats happening if the pump lever is moving properly.

toddao · Post by **toddao** » Tue Dec 29, 2009 6:11 pm

Has anyone suggested sludge in the tank? I had similar and persistant troubles and went through the whole range of possibilities : air leak ( also a possibility), diesel heater ( only on Mk.1s?) filter etc.
It was Doc who suggested having a peek in the tank : the fuel pick up was completely sludged up and it was a miracle it pulled anything at all. As well as that I had a pleasant hour 'fishing' through the access hole lifting out virtual jellyfishes of sludge!

demag · Post by **demag** » Tue Dec 29, 2009 6:24 pm

I thought Mulley said he was doing that.