75ZT Community

I have spent a couple of hours removing and refitting an Upper INlet Manifold on my KV6.

Upon refitting the replacement Manifold, double checking all pipes are fitted etc, I nervously started the car.

The car fired up first turn of the key and for a few seconds revved at about 1500 - 2000 Rpm then there was a strange raspy noise and the car started to backfire and run unevenly - Not lumpy, just revs going up and down but not high revs.

I am so upset now, I worked so hard today and was very proud of myself (I still am slightly as at least the car started lol) for completing my first "Non Trivial" 75 Job.

I have now broken two of the breather pipes removing the manifold again

Revs like that can be a sign of an air leak. You need to look at the underside of the VIS (Variable Intake System) motors and check if the rubber seals are in place. If one of then is missing it could give the symtoms you describe

Carl,

did you try starting it again?

I had one time after I did something (throttle body change I seem to remember) and I was quite worried. Started it again, and it ran fine and has since.

I can't think what it would be that caused it.

Dave is right: best guess is air leak from somewhere, or maybe the idle valve is wide open (giving too much air). Check all your sensors are plugged in right, too.

Thank you Dave and Duncan.

I had removed the Manifold again as I was in two minds whether or not to put the old one on again for now, as I need the Car on Saturday to drive to Lancashire.

However, I have noticed that I had not screwed the VIS Motor in (the one nearest the front of the engine) I am hoping it was just that.

The first of my Breather pipes arrived today and the second tomorrow, so I will not know until then whether or not that was the issue.

I have noticed a Plug, similar to the one that fits to the front lower of the throttle body (next to teh Battery box), with a spring clip, lying loose - It appears dirty on the inside, which leads me to think it was not connected, But I have no recollection of unclipping it, the only sprung clipped plug I recall was attached to the Throttle body, Any idea what that may be? I cannot find my PC Lead for the Camera so cannot upload pictures at the moment, though I will try and get a picture with my Mobile phone later.

Again thank you both for your responses

carlpenn wrote:Thank you Dave and Duncan.

However, I have noticed that I had not screwed the VIS Motor in (the one nearest the front of the engine) I am hoping it was just that.
:

Errrr, YES

The connector you describe will be for the traction control or cruise control, cannot remember which. I'm sure Duncan will be a little more accureate on that one.

takestock wrote:

carlpenn wrote:Thank you Dave and Duncan.

However, I have noticed that I had not screwed the VIS Motor in (the one nearest the front of the engine) I am hoping it was just that.
:

Errrr, YES

The connector you describe will be for the traction control or cruise control, cannot remember which. I'm sure Duncan will be a little more accureate on that one.

Thanks again Dave - I don't have Traction Control so it must be Cruise, but the only Sockets I see are on the Throttle Body and there is a Spring Clip plug there already, which feeds off a Plug that is connected at the top of the Throttle Body -- I am going to go get a Photo on Mobile now that its charged lol - Hopefully then I will make more sense hee hee.

P.S Thank you for not mocking the VIS Motor mistake lol......... I have been all morning.........

Spare plug is traction. You don't have it so it's not used. The only cruise connection up there is the vacuum pipe to the actuator, no plugs or wires.

The engine looms were common on all versions of V6 as far as I know so its a very common question. I worried the same when I found it on mine.

VIS loose. I think Dave gets the points for predicting this solution! Very likley the problem. You could run the engine without the breathers: they are often broken anyway and the only think you really notice is an oil smell in the car. However, you could just block the ends (though not with something that could get sucked in).

Thanks again Duncan.

I shall pop it all back together later and give it a try, will keep this thread informed.

I got a nice surprise earlier and UPS delivered my 2nd Tube kit, all fitted and the car drives superbly again

Thanks so much Dave and Duncan

I may need to replace the VIS motors as the "Power Boost" wasn't there at 3k and 4.5k Rpm.

Otherwise I am an extremely happy chappy, well with teh exception of having to make a thread about why my Remote Keys have stopped working now

I would go and check your PM box if i were you

Thank you Dave and pm sent back