I've just dropped a lower mileage 16v lump in my VTS, and as a trial run I put the basics back on (Inlet and Exhaust Mani, alternator, sensors etc) but left off some bits and pieces to check it was OK before refitting it all.
So I started it up, and it started with the first turn of the key - but it instantly revved itself stupid - and with it having no exhaust (just the Mani) it was making a hell of a racket, so I just turned it off again almost instantly.
So there's a couple of things I think may be causing the high idle (bear in mind none of the sensors or anything are any different from before - they all were working fine on the old engine):
- First and most obvious would be a sticking accelerator cable/throttle body. It's all been off to get the new Head/Block in so could be refitted wrong or sticking somewhere, or possibly got some gunk/debris in there while it was open.
- The second Lambda (that usually goes into the CAT on MK2 VTS's) was completely removed at the plug so the ECU would have been getting no readings whatsoever, could this be confusing it into over revving?
- Various sensors and hoses came off the inlet manifold and could have gone back on wrong, any thoughts on what could have caused it to rev so high?
Anything else people would think to check over? Could a loose brake vacuum hose cause it to do that?
I'm thinking I might whack the exhaust back on, so I can run it for longer without annoying the neighbours, and possibly plug in my Diagnostics Plug from my laptop.
So I started it up, and it started with the first turn of the key - but it instantly revved itself stupid - and with it having no exhaust (just the Mani) it was making a hell of a racket, so I just turned it off again almost instantly.
So there's a couple of things I think may be causing the high idle (bear in mind none of the sensors or anything are any different from before - they all were working fine on the old engine):
- First and most obvious would be a sticking accelerator cable/throttle body. It's all been off to get the new Head/Block in so could be refitted wrong or sticking somewhere, or possibly got some gunk/debris in there while it was open.
- The second Lambda (that usually goes into the CAT on MK2 VTS's) was completely removed at the plug so the ECU would have been getting no readings whatsoever, could this be confusing it into over revving?
- Various sensors and hoses came off the inlet manifold and could have gone back on wrong, any thoughts on what could have caused it to rev so high?
Anything else people would think to check over? Could a loose brake vacuum hose cause it to do that?
I'm thinking I might whack the exhaust back on, so I can run it for longer without annoying the neighbours, and possibly plug in my Diagnostics Plug from my laptop.
