Hesitation/jerkiness On Acceleration - Help Needed!

[pa402 0]

Hi

 

Since having my engine swapped for a lower mileage unit its developed a kind-of hesitation under load. When you accelerate there is a lack of power which then goes away as you get higher up the rev range. More noticeable when accelerating gently. Putting your foot down will mean it regains power. However this doesn't happen all the time, occasionally there is a sudden jerk where the car i guess has lost power for a split second. Its never cuts out.

 

The new engine was fitted with its original management which ive been assured was running spot on in its old shell. And this problem never occured under the old engine. I've swapped both leads, spark plugs, fuel relay and fitted a new fuel and oil filter.

 

Question is what to try next?

 

Cheers

[u47sb2 27 2 Cars]

Try AFM next? Or at least check all it's connections. I'd similar symptoms (almost a cough on half throttle but fine on full throttle and off throttle) - turned out there was crud in the connector that goes from AFM to loom

[Richy_cti 0]

colent Temp Sensor

[pa402 0]

Gonna sound dumb here - but is the AFM the black box next to the battery? And is the connector to the loom the big brown connector thats hidden underneath it somewhere?

 

Cheers

[Carbs4me 45]

correct ... its attached to your thottle body with a piece of black pipe.... on the bottom will be a plug with a thin piece of metal that clips them together press it and walla! its unpluged...

 

Also try cleaning your AFM with carb cleaner.. maybe abit nasty in there!

 

All you need is a flat head!

[shalmaneser 26]

Make sure it's not a misfire - as recommended above, check connections!

[DamirGTI 342]

Id try with something simple as - bump up the ignition advance a little bit .. and see if it goes any better afterwards ..

 

AFM ditto , but do look underneath the black plastic cover in order to inspect carbon track - slightly grooved is ok. , acceptable , but white spots/areas are bin no-no here .. re-tracking helps though :

 

http://www.frwilk.com/the944/afm.htm

 

Damir

 

EDIT : also , check if the dizzy vacuum advance canister (and the vacuum pipe which connects the TB and advance canister..) is in good nick ...

Edited October 5, 2010 by DamirGTI

[pa402 0]

Cheers guys

 

Will have a play over the weekend.

 

Nothing silly question - how do I advance the ignition?

 

Should have mentioned earlier that when the engine's cold (and idling high) there isn't much of an effect. Also - adjusting the accelerator cable (i.e. making it really tight) also helps, but only when its too tight and idles at 2k.

 

The vacuum advance I know doesn't work and never has.

 

Paul

[Carbs4me 45]

its on the right hand side of the cyclinder head (passenger side), unsure of its techincal name.... its the piece of metal your plastic dizzy attaches to.. but theres 2 bolts at either side. ( make a mark before you change its position so you can get it back to its orginal place. once you have made the bolts loose, it should move towards and away from you.... if i remember rightly towards you slows the engine speed and away from you speeds it up.