Hey everyone, this is my first post so if its in the wrong place I do apologise. 
 

I’ve converted my 1992 Polo Mk2F to an AFH running the standard injection and ECU. The way I did this was buying a donor car which was already converted. This car is a 1989 Mk2 Polo. 
 

The car runs and behaves normal on idle. However when I try to drive it, it bogs down at around 2500rpm in 1st and 2nd at partial throttle, if I floor it, it doesn’t happen. In every other gear it drives fine regardless of throttle position. 

 

I swapped everything over from the older Polo to try and rule out any issues. I did test drive the other Polo and it ran and drove without fault. However, now in this Polo its misbehaving. 
 

Any ideas?

 

Thanks in advance! 
Jack

Edited 3 September, 20206 yr by jackanyon
Removing possibly causes as after testing they’ve not resolved the issue

Welcome to the forum.

 

I'm just wondering if you may have a vacuum leak between the inlet manifold and the cylinder head, or indeed anywhere after the throttle.

 

A quick way to check for this, is to buy a can of  'carb cleaner'  (Halforsa or your local motor factor) and, with the engine idling, spray the carb cleaner around the manifold joints - any change in engine speed would indicate an air leak.

 

Regards

Thank you! 
 

I’ve picked up a few tins of carb cleaner, I’ll give it a go and see how I get on! 
 

I feel it’s beneficial to add that after today I’ve now replaced the coil, dizzy cap, and rotor arm with known working ones. I’ve also adjusted the throttle cable to remove the slack - this hasn’t helped. I have spark plugs on the way also, just incase it’s something simple like that. 
 

Thank you for your response! 
 

Jack

Just a quick update, I’ve replaced the spark plugs and its not helped unfortunately. I may try replacing the HT leads next but I’m unsure how much joy that’ll bring. 

 

I’ve also sprayed carb cleaner around all of the joins and mating surfaces on the intake manifold and throttle body. Not a single leak it would seem. I did also spray the cleaner into air filter just to make sure the engine would respond to the cleaner, and it did cause the revs to drop. 
 

I’m going to try cleaning out the throttle body and seeing if that helps.

 

Jack

scan it for codes ...hope you kept the diagnostic wiring

 

does it have adequate fuel pump /swirl pot like the factory cars or a ebay special in the engine bay

1 hour ago, steveo3002 said:

scan it for codes ...hope you kept the diagnostic wiring

 

does it have adequate fuel pump /swirl pot like the factory cars or a ebay special in the engine bay

It has the obd port still, no idea if it’ll actually work though. The donor car I bought was already converted to an AFH so it wasn’t me who did the wiring on it. 
 

I took everything from the donor car and swapped it to this one. Fuel pumps, loom, even the exhaust system. 
 

The car will pull through every gear all through the rev range with the throttle pinned. Its only at partial throttle do I have any issues. Almost like a tps issue. However I’m from the Honda world so this setup is a little unfamiliar to me. 
 

Jack