high idling vvc k-series at start

[allen l]

Just had the engine rebuilt. They tried to start it and the engine immediately revs at 5k rpm. We tried to block the inlet and the iacv and it still revs about 5 k and then shuts off by itself. Anyone had this before? We're a bit puzzled atm.

[allen l]

Absolutely no one with a clue what can be wrong or where to look at?
Months out of the running and really missing this part of enjoyment of life!

[ewenm]

I presume you've checked the throttle isn't jammed open/not closing properly?

[allen l]

Yes. We had had the airfilter off. The throttlebody was closed. We put a towel in front of it and took the iacv of. Started the engine and still 5k rpm. Very strange. the shop builds engines non stop, but for the first time they are puzzled. They've built an engine for me before, so I was certain I'd be on the road in no time.
Seems like we're missing something simple? Can't come up with anything to try atm.

[ewenm]

Big air leak somewhere bypassing the throttle?
Fuel injectors doing something strange?

[Mars]

Reset the throttle pot?
Air leak?
Poor mapping?
Cam timing? (less likely)

[allen l]

Mars said:

Reset the throttle pot?
Air leak?
Poor mapping?
Cam timing? (less likely)

If you mean the throttle position sensor, I've asked them to do that. It didn't help.
We've searched for air leaks, but it seems the gaskets are all in place. I'm still using the original ecu and I have not tuned the engine. So I guess it's not the mapping.

Would it be likely that the car immediately starts to rev if the vvc mechanism hasn't been rebuild correctly? I thought not, but I'm not sure.

[ewenm]

I'd have thought an engine would only rev strongly if it was getting a lot of air, so it must be getting in there somewhere.

[allen l]

Then I think something is being overlooked. Just can't think of what at the moment. A real bugger...

[Mars]

ewenm said:

I'd have thought an engine would only rev strongly if it was getting a lot of air, so it must be getting in there somewhere.

I agree with this.

[Incorrigible]

If the IACV was taken off, I assume they've blocked the hole where it should feed the plenum

[DVandrews]

You need a lot of air to get to 5000RPM, I would check that something hasnt come out of the plenum, such as the blanking stop in the top where the servo line normally goes. Check the PCV hose from the top of the plenum to the cam cover to ensure it has not come off and that it hasnt split.

Dave

[allen l]

Going to give the guy a call tomorrow. Hopefully I have some time to have a look myself coming week.

[johnvthe2nd]

did you get this sorted out? .. what was it?

[allen l]

Hi, to be honest, I don't know yet. Just got married this monday, so haven't called to the shop yet. Going to check it out myself next week if I'm alive again.