Still got problems- engine stalling acceleration?

[Terrence79]

Drove from the 25 miles from cheltenham to Worcester and it was faultless (combination of motorway and back roads) but on the way home the problems were back- try and put my foot down in 2nd and it just kangaroos like it's cutting out, if i accelerate slowly it seems fine most of the time but sometimes struggles. Sometimes it struggles to get going and stutters but then the power comes in fully and I can accelerate hard through all the gears.

I'm sure it's not the fuel system now and the pumps nice and quiet so where else can I look? Running out of time for Paris on the weekend!,

[jwigglesworth]

Have you tried the HT leads and/or spark plugs? Had a similar thing several years ago where it only showed the symptons when the under bonnet temperature got high coupled with putting the engine under load, new leads helped a lot. Just a thought

[Adrian@]

I've not followed anything more than this thread...have you checked that the throttle pot is wired correctly.
Adrian@

[Tant]

I had similar with mine a few years back....it turned out to be a small split in one of the hoses from the air flow meters to the plenum....it was barely visible but clearly letting in air. It would accelerate slowly on very light throttle openings, but kangarood like mad on anything more ambitious.

[Terrence79]

A bit more background, last year and after a couple of years of very very little use the fuel pump died, I had it replaced but the new one was struggling so after investigation it was discovered the tank was corroding from the inside and clogging the pump up, I've had the tank out and done the por15 treatment, cleaned the pump out the best I can, added an inline filter to replace the one in the tank that fell apart.

This weekend was the first time it's been back together and all was well, this mornings 25 miles went perfectly with all sorts of driving (cruising, accelerating hard, traffic etc) but after work it was back to how it was before with the kangarooing and stuttering.

I did notice when I put it back in the garage not long ago that the pump was noisey again (like its permantly working hard) so maybe i still have fueling issues between the pump and the engine.

As we are off to Paris on Saturday I'm going to take it into the garage by work and hope they can find something as I don't have the time (or talent) to sort this out before then.

[Loach1]

What level of filtration does your new inline filter have? I just went through the same stuff and installed a 10 micron filter, but the pump was growling at me after a few miles. I now have a 100 mesh (about 140 micron) inline strainer to go in its place, but I haven't got it on yet. If you have a pump with a built-in strainer (the Bosch one usually does) and have done the POR treatment, I would bypass the filter and go for a spin to see if it's cleared up.

David

[greymrj]

If the pump is noisy again it suggests it is starved of fuel and that the problem is pre pump rather than post pump. I am sorry but it sounds like pump and filter need checking again. I cannot remember what filter you fitted and therefore how easy it is to check?

I am not as familiar with the 2.9 (mine is an S1) but I do seem to remember that the 2.9 Sierra would sometimes develop a similar fault which was caused by some electronic component overheating. Car would run Ok when cold, or with bonnet open, but developed problems as you describe when warm. On the S1 that would be the 'ignition module' unit but the S3 is quite different.
Anybody else aware of this issue on the 2.9?

[Roy C]

Did you eliminate the TP?

http://www.tvrsseries.com/throttlepot/throttlepot....

[Terrence79]

I didn't want to risk the drive to work this morning so have booked the afternoon of to investigate, if the worst comes to the worst we will be be cruising Paris in a Fiat Punto!!.

The inline filter I added is syntec filter from demon tweeks - http://www.demon-tweeks.co.uk/motorsport/fuel-filt... - its comes with an 8 micon paper filter. I will bypass this this afternoon and remove the pump again to try and see if its still clogged, put in a new filter after the pump incase thats still blocked.

I'll also look into the throttle pot idea too as thats quite an easy check as well as check all the induction hoses incase there is a problem there.

Hopefully its still the fuel line as the morning drive was fine I cant see it being an induction issue as it would've been present then too? (would the throttle pot issue have shown up then to? it was a lot cooler yesterday morning but the engine was up to temperature all the same).

I will still book it into the garage for tomorrow incase I cant find anything today.

[Terrence79]

Contents of original filter- new one going on now

[Elfit]

Check this little resistor at the top of the fuel pump relay.
This caused me problems once. Make sure it's properly pushed in. It's a problem that took me ages to find ~ the "star tester" coupled with a waggle test is what found it in the end
Best of luck

Tim

[phillpot]

Terrence79 said:

Contents of original filter- new one going on now

Should there be a picture here

[Terrence79]

There should

Water in the filter (original filter after pump), put a new filter on and cleared the pump again, pumps still noisy and no change.

If there's water between the engine and filter will it clear itself slowly or just be stuck in there causing problems?

[phillpot]

Where did that lot come from if you've had tank out to treat with Por 15 ?????

I would disconnect fuel pipe at fuel rail and blow through all fuel pipes.

Have you changed filter "pressure" side of pump?

[Terrence79]

That's where it's from so I have put a new one on- stupidly didn't change it before

[Terrence79]

My Steve Heath book says there should be an accumulator between the the pump and fuel filter - I don't have this - should I and could this be causing problems?

[phillpot]

Terrence79 said:

My Steve Heath book says there should be an accumulator between the the pump and fuel filter

I believe that is an error, mine doesn't have one.
I suspect that is a generic description of the K Jetronic system, it also mentions a fuel start valve and a thermotime switch...I've not found those yet!


while it is undoubtedly a very useful book, not everything should be taken as "gospel"

[Loach1]

I finished putting mine together this evening, it ran well for a few minutes, then stumbled and died. I'm pretty sure my problem is that I have rust in the tank still, despite doing my best to get it all out. I'm getting fed up with this and might design a better tank and have it made from aluminium, or maybe just get a race tank?

It does sound like we have a similar issue - check your pre pump filter for trash.

The accumulator is for the 2.8 cars only, you don't need one since fuel pressures aren't as critical with EFI.

[Terrence79]

I'm going to have another go at it tonight, i'm sure theres no crud coming through from the tank as I was very an*l when doing the POR15 treatment.

When I turn the ignition on I hear the pump pressure up and stop as it should (so i'm assuming this puts the pump in the clear and working properly), when I then start the car the pump seems to be going again. My thinking now (after a bad nights sleep) is that there must be restiction between the tank and the pump as any restriction after the pump would only enable it to hit full presssure faster?

Due to the cars total lack for use over the last 3 years im ecxpecting lots of other problems to arise and I still need to check the trottle pot incase its that causing the stalling (at the moment i'm just concentrating on getting the pump to work as it should)

Only two days left so Paris in a punto I think!

[Terrence79]

Not the throttle pot, checked the resistor on to of the pump relay, not the filter between the pump and tank..... I'm beginning to think it's the pump itself.