Secondary ports on ZR1
Discussion
Well yesterday I fitted a new rh chain tenshioner (thanks Geoff/Nigel) and that all went ok this time around.
I then pulled the plenum (much easier than expected) to replace the gasket and re-torque the bolts that are know to come loose on the crankcase vent. They had come undone and there was a nice mess to clean up as well.
On putting everything back together this morning I thought I would check the operation of the secondary ports. All was working ok on the LH bank. Not so on the RH bank. when all 4 valves should be shut only 1 was and the others all open by different amounts. At WOT when all 4 should be fully open only 1 was the others being near to shut. I always thought it ran rich on the rhs.
On closer inspection it looks like the levers that fit on to each butterfly shaft had been over-tightened so much that the shoulder that locates them has give way.
Now looking foward to driving the ZR1 with all its secondaries open
I then pulled the plenum (much easier than expected) to replace the gasket and re-torque the bolts that are know to come loose on the crankcase vent. They had come undone and there was a nice mess to clean up as well.
On putting everything back together this morning I thought I would check the operation of the secondary ports. All was working ok on the LH bank. Not so on the RH bank. when all 4 valves should be shut only 1 was and the others all open by different amounts. At WOT when all 4 should be fully open only 1 was the others being near to shut. I always thought it ran rich on the rhs.
On closer inspection it looks like the levers that fit on to each butterfly shaft had been over-tightened so much that the shoulder that locates them has give way.
Now looking foward to driving the ZR1 with all its secondaries open
Hi Brett,
How come you changed the cam tensioner, was it cos of noise on startup?
Also, how did you test the port throttles, funnily enough I have my plenum off at the moment to clean up all the oil and muck under there and check for vacuum leaks. Might as well test mine whilst I'm there.
How come you changed the cam tensioner, was it cos of noise on startup?
Also, how did you test the port throttles, funnily enough I have my plenum off at the moment to clean up all the oil and muck under there and check for vacuum leaks. Might as well test mine whilst I'm there.
I just looked down the ports, you can see the valves clearly enough. They should all move together and be in the same position. Have you checked the bolts on the crankcase vent ? Mine were all a few turns out ? Its a pig to get to though. Once the plenum is off you need to remove the vacumm gear, a/c compressor, I also pulled the coil packs and the starter motor so I could get down there and clean up all the mess. To remove the cover in order to fit a new gasket I then had to take out the secondary vac pumps, the 2 covers each side and the linkage under neath on each side. That gave me just about enough room to get the cover out. You can test the vac pumps and for leaks etc if you have a vacuum pump.
What makes you think you have a vac leak ??
What makes you think you have a vac leak ??
Sounds like a lot a lot of work there, I think I'll clean it up as best I can and check the vacuum lines and put it all back together. My motto is if it isn't broke, don't try to fix it.
I took the plenum off cos I could see a bit of oil in the valley, no problems with vacuum leaks, but just wanted to check that the pipes hadn't all gone brittle. So far everything looks OK
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