ABF spluttering

[oakgreengolf]

Since it has gone in my mk2 its now spluttering under acceleration. It starts and Idles fine and runs ok, just when you give it a few revs. Its like there's not enough fuel getting through?
Ive checked plugs and leads. lambda sensor is plugged in. fuel filter is fairly new. Any ideas

[Diamond Hell]

Does it do the same if you unplug the lambda?

[danny_p]

as dh said  unplug lambda,   if still plays up check pipework to map sensor   and wires to tps

[oakgreengolf]

Ill have a look tonight. Am i going to cause any problems driving it as i need it for work 

[Diamond Hell]

Shouldn't do, provided you don't thrash it, although it might run rather rich (better than lean anyway).

[oakgreengolf]

Finally got round to taking the car to the garage. He admitted he hadn't spent much time on it as he was busy  . Anyway went for a spin round the block with him and managed to get through the spluttering and it will rev freely over 4k. He suggested it was more of a flat spot? He also suggested the fuel pump maybe the problem. the kr runs at 5bar of pressure where as the abf is 3ish. I have unplugged the lambda today and there is no change, ive also checked for leaks, changed the relays, dizzy and arm.

[Diamond Hell]

Fuel pressure *should* be regulated by the regulator on the end of the fuel rail, so the pump *shouldn't* make that much difference, as it should be over-specified, if anything.  Possibly replace the fuel filter and maybe test the pump for flow and pressure, if you can get access to those facilities.

Did your last engine grenade itself, or was it just worn out?

[rubjonny]

try a couple of drops of machine oil down the vac hose connection on the fuel pressure regulator.  A couple guys on clubgti reported this fixed a problem on their cars, apparently the fpr can get a bit sticky?  Not had this issue mesen but since its free well worth a try!

Just to add when I fitted an abf to james' mk2 we used a kr 16v fuel pump, and it ran no problem at all.

[oakgreengolf]

DH my old engine dropped a valve so not sure whether its related. Ive got no way of testing the fuel pressure as for the fuel filter its fairly new so this shouldn't be the problem. Its definatly over fueling as the plugs are very black so im thinking lambda, MAF, or a sensor of some sort?. The garage checked the emmisions and the HC where very high which he said is unburn't fuel. Ive got the lambda at the bottom of my 4 branch after the flexi joint could this be causing a false reading, although as i unplugged it i thought i'd have seen an improvement. Ill give that machine oil a blast too.

[Diamond Hell]

It won't be the MAF, as there isn't one. 

Might be the MAP (Manifold Absolute Pressure) though - is the vacuum hose connected to the ECU? 

Is it getting temp signals to the ECU loud and clear?

Got a photo of that lambda install?