Hesitation under power

[nobleguy]

I noticed yesterday that I get a slight hesitation at full throttle, only for a half second or so, and then behaves normally. Anybody else had this and/or know wht might be causing it?

Thanks in advance.

[gadgeroonie]

could be a whole load of reasons

best to get it looked at

[joust]

Air leak is normal answer - get it checked out.

J

[nobleguy]

It feels as though a seal is being breached under pressure (low revs, foot hard down), and then I'm guessing the pressure is dropping slightly to allow the seal to sort itself out. I also found an old post which mentions my symptoms and it sounded like one of the small tubes around the throttle body was working loose.
Might double-check them first, then let a more trained eye take a look.

[joust]

If it's the 'rubber elbow' joint that comes from underneath the throttle body you normally get increased idle revs at the same time. Definitely worth a check of all of the vacuum lines though.

[nobleguy]

Hmmmm. I've noticed it does search a little at idle and then opt for the higher range just from listening to it.
Thanks for the info btw.

[joust]

nobleguy said:

Hmmmm. I've noticed it does search a little at idle and then opt for the higher range just from listening to it.
Thanks for the info btw.

Air leak or similar then. Get it to Dealer/Roush/Plans etc.

J

[fastandfurious]

I had these symptoms on mine some months ago.First trip to the dealer had fuel filter cleaned, signs of water ingress in the fuse box etc.It might have been my posting where the elbow on the throttle came up and you refer to.
It turned out to be a fuel leak, I had detected a smell of fuel around the car when in the garage.
It gradually got worse and then started running badly and I had her recovered to a dealer.
Quote "It had the worse high pressure fuel leak they had seen".Turns out the fuel line had been chafing against the chassis.Had that replaced and it hasnt skipped a beat since.

Edited by fastandfurious on Monday 16th April 19:43

[nobleguy]

Sorry about the resurrection of this, but Elite mentioned thay had a 3R down there with the same symptoms and it turned out to be one/more of the spark plugs. Was this anyone on here?

[actech]

I have these symptoms a few times now all with different causes.

First was with a creased vacuum pipe, second was with a split vacuum pipe and the third time was because the throttle idle adjust screw had moved (either over time or by a suspect service engineer!) and the adaptive mapping had tried to compensate and maxed itself out.

The first two I spotted and easily fixed, the third was spotted as soon as the ECU monitor software was plugged in and the adaptive maps were reset back to default.

Hope this helps
Anthony

[snuffy]

I had huge hesitation when accelerating a few months ago. It was running like a dog. First of all it cut out at low revs in traffic. It started okay and then ran very badly. I limped for about 5 miles and then stopped the car. After a few minutes I restarted it and it was fine. It's never done it since. Very odd. The only thing I can think of was water ingress. The car had been out all night and it had lashed it down. It took maybe 70 miles for it to behave as I have described. As it's not done it since so I've not worried about it.

[obes]

yep, I had a horrendous mis-fire after washing the car recently - put it down to getting water in there somewhere. Once it was hot it was fine and has been since