Poohberg on a Polo

[jim91]

I know it's not a Rocco, but just put my Polo back on the road for first time since I bought the rocco ( over 2 1/2 years )

I've a 1990 1043cc MK2Polo with a pierberg. I couldn't get it to idle and so when offered a carb off a 30K engine fitted that. Eventually got it set up right by a mechanic and ticking over lovely, but there's still a dead spot.

It seems ok when on autochoke, but once I get to bottom of street and chokes off starts its nonsense. When you let off the accelerator and then put it down again it dies then picks up again. This is really noticeable when changing gear at lower revs, or if you slow coming into corner or roundabout etc.

I had it out a good 60 odd miles today, most of which 70mph on motoway and its going great but still hesitates.

Anyone any ideas? was thinking must be similair enough to a rocco pierberg. Asked on polo site, and only got one reply, guy thought maybe accelerator diaphram, checked the Haynes book of lies and can't see one on carb diagram.

Heeeeeeelp before i take a sledgehammer to it

[Nate]

1.05 according to my book should be fitted with a single stage 32 1B3 - not really that similar to the rocco one.

the suggested causes for hesitation are defective or sticking accelerator pump piston, worn accelerator pump lever or shaft or a clogged accelerator pump injector. the last is probably the most likely if it has been sat for a long time. the fuel that was left in it may have solidified slightly.

first thing i'd try would be to blast it all out with carb cleaner, then chuck a full bottle of redex thru it, but without filling the tank right up so it comes thru nice and strong

[jim91]

Cheers dude, spot on it is a 1B3, already ran a bottle of Lucas stuff through it when just £5 of petrol in, I remember someone telling me before about diesel to clean a carb??? Would it be worth connecting the fuel line to a wee cup of diesel and turning it over? ie would that break up any solidified fuel in jets?

Cheers for response dude

[Nate]

that's a new one on me! as a general rule, petrol cars don't like diesel

[jim91]

Apparantly it's very good cleaning properties, heard of people throwing a cup into carb, or into tank (I wouldn't reccommend this as i bought £5 petrol contaminated with diesel before and car ran like crap for over a week). Was thinking if just pumped into carb would work its way through and clean jets etc out better??

[eamon1.3]

How hard is it to split the carb and get at the jets? I cleaned the jets once or twice on my red golf, pretty easy on the weber though

[Nate]

whip the air cleaner off, and you can unscrew the jets and take them out really easily. just blast them through with some carb cleaner then some compressed air (assuming you've got access to a compressor)

don't be tempted to poke anything thru them to clean them. this will damage the inside of them and you'll never get it running right. i'll try and get some diagrams of how to get the jets out emailed to you later tonight. gotta get back to work now

[jim91]

Cheers Nate! I split the old carb to see where piston etc was, but wasn't sure how to get jets out
........... unless eamon wants to get off his lazy ass and wreck some carbs with me

I take it the gasket should be ok without replacing it? I think they're obsolete now

Cheers for the help dude, much appreciated

[Nate]

sorry it's a photo not a scan, having trouble getting the scanner to work properly. the jets are numbered 9 and 10

[eamon1.3]

I thought the jets where burried in the carb, maybe they are in the bgger ones? Look easy enough to get at, get stripping jimbob. If you need a hand you know where i am.

[jim91]

Cheers Nate, have to go to ikea and fill it with stuff now so I'll have a hoke at it later. What's easiest way to get them out, they look threaded in diagram. Is there a recess on top, or do you need to split the carb and screw from below?

[Nate]

i've only ever taken them out of the 2E2 and 2E3 carbs, but they are usually have a slot in the top. just unscrew them with a screwdriver. blast some carb cleaner down them and then blow them out with compressed air (you can buy it in a can of you don't have a compressor, but it's very expensive)

[jim91]

Cheers again buddy your a saviour!

[jim91]

Jets out carb cleaner in them then airline blown through, not a blind bit of difference
Might have a look at that piston in the carb, you reckon be ok to open it and not replace gasket when back together?

Ready to kill this!

[Nate]

have i got this right, the fault is now still the same as it was before you changed the carb? if so, that would kinda point to it not being the carb at fault surely? (sorry, i think i may have misread your original post)

have you checked for vacuum leaks? does it have the rubber flange under the carb the same as on the rocco?