ongoing re commission of our RX7

[rustyrescue]

Just a thought but are the secondaries opening ? I had a similar problem when I had my carb rebuild.

I will double check....thanks, however I think they are because as I push further building up revs on the loud pedal it picks up and revs cleaner (workshop) as if the secondaries just come on.

[rustyrescue]

When it’s missing and playing up, what happens if you pull the choke out? If stabilises things then you are probably running lean due to a vac leak

Tried that today, sat running on drive till warm. Built revs gently to about 2500 and they were dropping up and down from about 2000-2500 and pulled choke out...no difference. Revs carried on wavering.

[rustyrescue]

A thought though, would the janspeed manifold and exhaust cause it to run lean? need jetting up? like my bikes. Standard air filter though on this. Plugs are decent colour but it gets warm when trying to drive holding fine idling/stationary.

No, nothing to do with the Janspeed system. Sounds like a vac leak or maybe the idle circuit in the carb, possibly a combination of both?

If you can post some pics of the carb, that would help with diagnosis. There is a plate that sits between the carb and the inlet manifold. it has a number of vacuum hose connections. Any that are not connected need to be capped.

Tim White at RX Motors should really be your first call.

Thanks, I will post some pics and may end up talking to specialist. That plate has no open connectors. The big one is capped. I cant see any leaks and have sprayed carb cleaner around all joints with it running which usually finds vacuum leaks. There are 5 connections remaining on the plate. Two go to the advance retard units which work and are not ruptured in the diaphragms. The other three go to things I dont really know what and wonder if it should all come off!!

I do notice where the metal pipes are mounted in the plate they have white stuff around them, is that factory or has it been got at?

[KiwiDave]

Leave it all on there for now until you can pinpoint what the running issue.

The other connections are vacuum sources for the emissions setup. One to the air box, one to the EGR valve and one to the oil breather from memory. It's all connected via the 'rats nest' mounted on top of the engine. Easily deleted as long as you ensure that all the unused ports get capped off.

Our FB's are excluded from the MOT emissions test (visual only) so the system, including the air pump, is not required.

The white residue around the ports might just be a metallurgic reaction. (this term may well be incorrect). I believe that the two metals may be different. (my theory anyway LOL).

[rustyrescue]

Leave it all on there for now until you can pinpoint what the running issue.

The other connections are vacuum sources for the emissions setup. One to the air box, one to the EGR valve and one to the oil breather from memory. It's all connected via the 'rats nest' mounted on top of the engine. Easily deleted as long as you ensure that all the unused ports get capped off.

Our FB's are excluded from the MOT emissions test (visual only) so the system, including the air pump, is not required.

The white residue around the ports might just be a metallurgic reaction. (this term may well be incorrect). I believe that the two metals may be different. (my theory anyway LOL).

Thanks, I am sure we will fathom it out before too long and then yes I think delete as much of that vacuum rubbish as possible! some already gone before us including wherever the pipe for that idle compensator in the airbox comes from, and the think on the end of the manifold.

158125514_935443777264379_1984241532324613338_n.jpg (221.08 KiB) Viewed 117433 times

[Casey]

Not sure if this will help Russ? Old pic of my vacuum setup on KIMI 2 (which is now sold). I know others have removed even more (including the vacuum solenoid with the light blue connector).

Vacuum Nest 1024.jpg (147.68 KiB) Viewed 117426 times

[rustyrescue]

well, I reckon that may be about what ours has on it, 2 vacuum advance retard units, and those 2 thinks on top of the engine, the black plastic one with an electrical plug and the one with two connections of a larger hose and smaller hose....not sure what they do!

[rustyrescue]

So it is back to the carb, one on parts on my bench I know worked well on a car in use until about 18 months ago when the engine was pulled out and carb put in store.....So it should run following a clean etc.
I hope someone can confirm a fault on this carb....previous work done wrong!

The accelerator pump has two check valves...inlet and outlet. My manual shows both these valves having the ball bearing in the hole first then the weight on top. My outlet valve was just like that, the inlet however was the other way round. The ball bearing on top of the weight, seems wrong to me?

Am I going mad or have the B up brigade been there before me?

[rustyrescue]

Next instalment and may be getting there but a little advice on carb set up would be good!
I have gone through another carb, cleaned, set it up and fitted. The car sounds stronger, runs cooler and generally I suspect is going to be better when we try to drive it.
However, no matter what I do with the air and mixture screw I cant make it tick over right, the last carb did!
To make it idle at all it has to be screwed right in on the mixture screw and right out on the air screw...it hunts bad though.
I have found if I just rest my foot on the throttle pedal, literally a touch I can make it idle just lovely with the two screws roughly where I would expect.
I did set the spindle/butterflies as per workshop manual but I wonder if I should alter the adjustment to open them just a little? it would be easy if it had a normal idle screw acting on the spindle!

[Casey]

Sorry I'm unable to help with your queries, but following with interest.

I have a carb in pieces at the moment. 9/10 of the bits have been cleaned and I have a rebuild kit ready for re-assembly. When I come to install it, it looks like (from your experience), I'm in for some snagging too