General Mk2 uno turbo running problems

[unoturbscj]

hi all, i am needing some advice on my mk2 uno turbo which i recently bought as a project. When i first got the car it had a severe boost leak, which ive cured to the best of my knowledge. The main problem i am having now is it seems to be lagging alot on boost. It will boost up to 8psi untill i hit 4500/5000rpm and then boost goes to 12psi but then it starts miss firing. If any1 has any suggestions let me know cheers

 

[Louie Bee]

Sounds like the waste gate may be stuck closed on your turbocharger.

the misfiring probs would be caused by the over boost protection switch which people who purposely up the boost disable. don't disable it unless you up the fuelling and have rolling roaded or it will soon go bang with a stuck waste gate

May be able to free it off by working the actuator by hand with it all still on the car

 

[unoturbscj]

hi thanks for the reply, i thought about this when i was checking all the boost pipes so i checked to make sure the waste gate was moving freely and it does, but there was a piece of tin folded over the actuator bar holding it to the waste gate. So i think the actuator has been adjusted do you think this could have something to do with it if so where abouts do i adjust it too.
cheers

 

[unoturbscj]

I have now been and changed the rotor arm, dizzy cap and plugs and leads and been and set the fueling at my local mot station. there is aslight differance but its still finding it hard to boost before 5000rpm and then developes a missfire mainly in first and second gear, ike it goes down on a cylinder but no pops or bangs like on overboost,
i dont know what else to check coz it all seems fine. My old ut had a similer sort of problem but was just a split pipe

any 1 got any ideas

 

[Ucof]

Could be a split pipe.

 

[unoturbscj]

I have checked all the pipes and there is no sign of any split pipes.
Any chance it could be the ct switch

 

[lukey25]

i have a punto turbo and im getting the same kind of problem but i only can get up to 2500rpm anything about and it splutters an backfires.. ive changed plugs n leads and the air intake hose as it was split but still having same problem.. will the dump valve dump if wastegate stuck open??

 

[alexGS]

Dump valve depends on manifold vacuum, I don't think that will depend on whether the wastegate is stuck open or not.

However the dump valve itself could be the cause of problems... it might have a leak, and effectively becomes an air intake leak then.

-Alex