Engine hesitating!!

[zzr1200]

My car has never been smooth since I got it but it is now hesitating all the time, right through the rev range. I suspect a number of things which I am going to work through.

1. Coil breaking down
2. Sooted up HEGO sensors
3. Low fuel pressure/fuel pump problem

I have cleaned up the rotor arm, dizzy cap and re-gapped the spark plugs, the HT leads are fairly new, although one has a burnt sheath at the plug end.

I replaced the fuel filter and the coolant temperature sensor a couple of weeks ago and the stepper motor and throttle potentiometer are both ok.

I have noticed a small wiff of petrol as I start the car, maybe a injector problem?

Can anybody think of anything else that maybe causing this??

Thanks,

Paul

[big_treacle]

zzr1200 said:

the HT leads are fairly new, although one has a burnt sheath at the plug end

Although you said your leads are new, one of mine (nearest the driver) burnt its sheath & it made my engine hesitant. Not sure what causes this to happen tho.
Once I'd replaced the lead it was completely fine.

[zzr1200]

It's the same lead on mine. Best thing is for me to do that first and see what happens.

I have had to replace some of the spark plug extenders as they were loose and the leads kept resting on the exhaust manifold.

Paul

[chim 500]

if it is any help mine played up at 3000/3500 revs it was the coil.

[zzr1200]

chim 500 said:

if it is any help mine played up at 3000/3500 revs it was the coil.

I did change the coil last year but only for a cheap one so I may change it again, HT lead first though.

Paul

[shadowninja]

Might be worth checking how secure the caps are on the plugs... one of mine came lose after i drove over some bumpy unsurfaced road... went all funny, letting it idle did nothing, giving it more gas did nothing. figured something else was amiss... one of the caps over the plugs had loosened!

[zzr1200]

I put a new set of leads and a higher output coil on today, more power but still hesitating. I suspect it could either be an injector sticking open or a spark plug breaking down, so I've ordered a set of bosch super 4's and am going to check the injectors are closing by checking the fuel pressure drop off.

paul