starting up after a cylinder head rebuild

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runoutofmoney
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Posts: 4
Joined: Thu Jan 17, 2008 8:39 pm

starting up after a cylinder head rebuild

Post by runoutofmoney »

Hi,

I have just finished rebuilding the cylinder head on my 1995 1.6 polo and have some questions now i have fired it up for the first time. I replaced the cambelt when i had the head off and reset all the timing. I started it up and it ran at about 1500 rpm for about 30 seconds before dropping to about 800 rpm for about 10 seconds, which i guessed was the idling speed, suddenly it then shot up and stayed at 4000 rpm for a minute before i bottled it and turned it off. Every time i turn it on it revs up to 4000 rpm and stays there.

The car has had the battery disconnected for the past 4 months so my question is this, it the ECU just finding out all the running settings or could i have done something wrong during the rebuild.

Any help would be most appreciated.

cheers

James
wullvfr
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Posts: 16
Joined: Sun Feb 08, 2009 10:24 pm

Re: starting up after a cylinder head rebuild

Post by wullvfr »

hello-

did you do everything correctly whilst putting the head back together?

timing is spot on?

for it to rev up like that it will need extra fuel air so there could be a vacuum leak etc!!!!!

is all connections correctly fitted,all sensors?



william
runoutofmoney
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Posts: 4
Joined: Thu Jan 17, 2008 8:39 pm

Re: starting up after a cylinder head rebuild

Post by runoutofmoney »

Hi William,

Cheers for the reply. I managed to figure it out in the end after taking the air filter off. The throttle cable had not fitted into the recess and was pulling the throttle open. I think the ECU then tried to work out the initial setting and it settled down after i fitted the throttle cable properly. I do have a problem with it sounding like it is missing every now and then and occassionally when you put your foot on accelerator pedal it feels like it is only running on 3 cylinders and lacks power. There is a new distributor, leads, plugs, coil and i know the head is okay as i have just rebuilt it with new timing belts. I have a feeling it is now the fuel injector or a sensor making the engine do this.

More investigation to follow.
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