Stutter when accelerating

[martinj46]

As above, my car has developed a strange stutter/judder when accelerating. It feels like a fuel cut, and gets progressively worse as the petrol tank level gets lower. The strange thing is it does it intermittently. Initially it only did it when using vtec, but now it's doing it throughout the rev range.

The car is standard other than an apexi intake (filter is fairly clean and free from crap) and spoon b pipe.

Recently it's had an oil change, and fuel filter change. Changing the fuel filter has reduced how often it's cutting in, but not completely. The spark plugs were changed late last year also. I've also ruled out a bad batch of fuel, as its done it with several tanks now. My scan gauge is showing no fault codes.

Any ideas? Cheers

 

[dave c]

spark plugs not firing maybe? Is it like a misfire? I'd swap them first

 

[PORTHOS]

Mine was doing this, turned out it was a leaky spark well seal.

Not sure that is your problem, but worth checking if any fluids are getting in there.

 

[Riz]

I don't know much about cars, but when my bike was doing that it was a blocked fuel breather.

 

[davidpingu]

Maybe coil pack could be on the blink too? Obviously check the above suggestions first

 

[integraleo]

After all the above might be worth getting injectors cleaned too,they might have picked up a bit of crap at some point.
It's one of those jobs I keep meaning to do but my car is my daily driver and I never want it stood up for few days while I send injectors off

 

[martinj46]

Cheers for all the replies.

spark plugs not firing maybe? Is it like a misfire? I'd swap them first

It's not so much a misfire, but I'll check them out and possibly swap them over, fairly cheap place to start.

Mine was doing this, turned out it was a leaky spark well seal.

Not sure that is your problem, but worth checking if any fluids are getting in there.

I've had a look and it seems to be free from any fluid.

After all the above might be worth getting injectors cleaned too,they might have picked up a bit of crap at some point.
It's one of those jobs I keep meaning to do but my car is my daily driver and I never want it stood up for few days while I send injectors off

I forgot to mention in my OP that Just before swapping the fuel filter, I put some redex type cleaner through the system, so it should all be clean. Would it be worth putting it through again with the new filter fitted?

I'm fairly sure it must be a fueling issue, as changing the fuel filter definitely improved it. After asking around a few mechanic friends, they are all suggesting it's the fuel pump that's given up. Integrastella has them for £25 so that's not a problem, but before I try that does anyone know what fuel pressure the pump should be running?

Thanks again for all the replies so far, they are all greatly appreciated

 

[c7frw84]

I had a slight stutter/hesitation when accelerating I'm my car also, I was speaking to the guys at funky power about it and they said I should try putting forte fuel injector cleaner through the engine, this seems to have cured my problem and the car also feels more responsive now, not sure if it's the same problem that your experiencing though

 

[davidpingu]

I had a slight stutter/hesitation when accelerating I'm my car also, I was speaking to the guys at funky power about it and they said I should try putting forte fuel injector cleaner through the engine, this seems to have cured my problem and the car also feels more responsive now, not sure if it's the same problem that your experiencing though

Forte stuff is real good. I used a seal conditioner in the oil on my BM as it was going through a litre of oil every 2k miles and it reduced my oil consumption to about a litre every 3500 miles. Still high but a good improvement!

Best uprate the fuel rail and injectors just to be sure I think

 

[martinj46]

Cheers guys, I've ordered some of the forte stuff, and a fuel pump from integrastella just incase.

A mate has suggested another possibility, apparently there is a gauze like filter on the injectors that easily gets clogged up. Is that something that the forte stuff will clear, or is it a take out and clean/replace job? I've never done anything with injectors before so it would probably be going to a garage if so.

 

[davidpingu]

To be honest you shouldn't have particles large enough to block the gauze like that but it can't hurt to check I suppose. They are easy enough to remove yourself, just unclip the plugs from the injectors, disconnect the fuel pipe via the clip on the rail and it's just 2 nuts to remove the rail and all injectors from the inlet as one piece.

What fuel do you usually use?

Shame you can't use a kpro for a few weeks and record your A/F ratios.

 

[martinj46]

No harm in checking. Cheers for the advice.

I use v-power 99% of the time. And the other 1% is tesco momentum, although that's usually just a splash to get me to a shell garage haha

 

[davidpingu]

Vpower is a nice clean burning fuel so unless a previous owner ran it on vietnam grade fuel and let a lot build up at the bottom of the tank it won't be that I wouldn't think. Besides I don't think the tank is old enough to suffer with that and the fuel filter should do its job. These problems can cause a real headache but unless you're willing to spend money in to a lot of diagnostics it's probably a case of running it til it gets bad enough to throw a light. I think my money would still be ignition related from what we know as something fuel related would end up with you running to lean and perhaps more knock etc?

Electrical faults tend to be more intermittent than fueling I'd think as something like a blocked injector would be a consistent thing rather than just now and then. Maybe changing the fuel filter is more coincidental than anything?

 

[martinj46]

UPDATE: today I swapped the pump over with one from integrastella, and all is well again when I changed the filter a few weeks back, part of the assembly had snapped off previously, so my guess is shards of broken plastic have maybe been sucked up into the pump? Just a guess though, but I'm delighted its fixed. Just in time too, I leave for Spa tomorrow

Thanks to everyone for the suggestions

 

[c7frw84]

Glad to hear you got problem fixed mate