Slight hesitation when accelerating

[petros]

Any suggestions would be welcome. The car suffers from a slight hesitation when accelerating and has also stuttered a couple of times at a steady 70ish mph, in that she starts to pop and bang as though one cylinder is not getting a spark. work done in the last 8 weeks includes... Engine blueprinted by power and heads ported, gas flowed and performance cam fitted. New fuel pump and regulator.New Dissie cap, leads, plugs and shrouds.New tune resistor.New coil.At a loss as to what else to feckin change....

[GreenV8S]

Has the ECU been mapped to suit all those changes you've made?

[petros]

Sorry, brand new Eprom chip supplied by Dom at power as well

[GreenV8S]

Given that you've recently had major work done on the engine, I think it would sensible to ask Dom to have another look at it as the first step.

[petros]

With Ian at Middlewich at the moment and he's struggling to find the problem, but he's convinced it's something silly

[Gaffer]

Peter

I have the same chip as you and mine does the same thing but it doesnt bother me.

Claire

[grif500]

Hi Peter, good to see you again the other day

Sorry to hear you're still having these problems, do you mind if I join the bandwagon

As you know, mines had exactly the same work carried out (minus the chip) and guess what, same problems as well...

I haven't had power-loss at speed, but Ian did mention that it cut out on him during his testdrive. At the moment though mine is hesitant under light throttle, and almost stalls at junctions, etc, when warm (seem to remember you mentioning this as well when I last saw you).

Hope you get yours sorted soon, if I manage to figure our what's going on with mine in the meantime I'll let you know

Claire, just out of curiosity, is yours really as bad as that? I know you use yours everyday, but with mine like it is now that would drive me insane, plus I'm sure the misfires can't be good for the engine.

>> Edited by grif500 on Tuesday 11th April 09:03

>> Edited by grif500 on Tuesday 11th April 09:04

[Gaffer]

Hullo

Dont forget Miss D is fubared anyways. The hesitation did worry me in the beginning but I know there is nothing major to worry about (I am more worried over my clunking in 5th TBH).

I suspect its the chip being a bit slow to react (now Ian will shout at me for trying to figure out what it is) but thats all I can think of in my very limited mechanical knowledge. I came to this conclusion as when I accelerate, it does take a split second for the car to respond, I am presuming that the chip has something to do with how fast the car accelerates (as well as hitting the loud pedal).

Just going to ride it out and see what happens. I will ask Ian (read bribe him with Wine Gums) to reset the timing when he services her at the end of the month.

Just take it easy in the meantime and try not to worry too much. I know I have bigger things to worry about at the moment and Miss D hesitating is rather far down my list,

Take care

Claire

[grif500]

Gaffer said:

Hullo Dont forget Miss D is fubared anyways. The hesitation did worry me in the beginning but I know there is nothing major to worry about (I am more worried over my clunking in 5th TBH). I suspect its the chip being a bit slow to react (now Ian will shout at me for trying to figure out what it is) but thats all I can think of in my very limited mechanical knowledge. I came to this conclusion as when I accelerate, it does take a split second for the car to respond, I am presuming that the chip has something to do with how fast the car accelerates (as well as hitting the loud pedal). Just going to ride it out and see what happens. I will ask Ian (read bribe him with Wine Gums) to reset the timing when he services her at the end of the month. Just take it easy in the meantime and try not to worry too much. I know I have bigger things to worry about at the moment and Miss D hesitating is rather far down my list, Take care Claire

Fair enough, kind of makes sense to me as well (I'm not exactly mechanically minded either though - just ask Ian what c*ck up I did yesterday... )

I guess your other concerns do tend to make anything else fairly insignificate, best thing to do is drop the top on the Chim and go for a good blat, always cheers me up no end!

No doubt see you soon at Ians

Karl

[GreenV8S]

If it goes flat when you open the throttle, this could be a clue that the throttle pot isn't reading correctly. Depending how bad it is, this can also cause the engine to splutter and/or die while you are cruising.

[robertjp]

Green V8S,

Sorry for thread highjack but it is still relevant. My Cerby has a slight flat spot when under haevy load - seems to occur just after a quick gearchange there is a slight hesitation before puching me back in the seat.

Could this be the same ie throttle pots not optimised?

[will.naylor]

Hi all.

New to the glorious world of TVR and recently bought a 95 Chim 400. Love it to bits (I am NEVER gonna get bored of the noise!!!) but I get a flat spot (esp in 5th) around 3000rpm.

Not too mechanically minded so any assistance would be much appreciated.

Cheers

[Gaffer]

robertjp said:

Green V8S, Sorry for thread highjack but it is still relevant. My Cerby has a slight flat spot when under haevy load - seems to occur just after a quick gearchange there is a slight hesitation before puching me back in the seat. Could this be the same ie throttle pots not optimised?

Could just need setting up on the laptop...? Not sure how Cerbs work but I do know after Ian has set them up they are 100% better.

Claire

[argoose]

Peter

Friend had the same problem, which turned out to be a sensors on exhaust manifolds.

He had replace the old exhaust system with stainless steel manifolds, which can get very hot to the point that it had burnt out the sensors.

Just an idea, hope this helps.

[petros]

Right, must get Ian to change the lambda sensors, after that I think the only thing under the bonnet that's not new is the Stay.... mmmmm, could be the problem I suppose, must look on E Bay for a Carbon Fibre go faster Bonnet stay.