I believe my 200 is too rich.
At idle I can get it to stumble by screwing in the idle air screw, which is supposed to make the idle richer. If I screw it out, I can keep screwing it out all the way with no change in idle speed.
I have just fitted a SV valve which I bought from Frank, and the car fired almost straight away but then stalled and wouldn't restart until I disconnected the SV valve.
So this tells me the idle is to rich, so after it started the engine I pulled the SV hose off the mixer which increased the idle and it was noticeably smoother.
I turned the "lean, rich" valve at the gas inlet but this made no change as I guess the flow of gas at idle is so low that this adjustment makes no difference.
Should I be able to adjust the idle mixture screw and get the engine to stumble at the lean end as well as the rich end?
PS:
The diaphragm reinforcing plate has "85" written on it.
Thanks.
Tuning Impco 200
I had a similar issues on my 425 over the yrs
1sttime, fond if wound the spring out to far then back in the scew didnt re sit corect , had to take the cover off the diapham and re set
2nd time the diaphame had a tiny hole in it..possbly from the above???
Resently ....I checked the rubber seat marks on the diapham, they appeared to be seating but not square on the port, but only just
a very slight 'tweak' fxed.
1sttime, fond if wound the spring out to far then back in the scew didnt re sit corect , had to take the cover off the diapham and re set
2nd time the diaphame had a tiny hole in it..possbly from the above???
Resently ....I checked the rubber seat marks on the diapham, they appeared to be seating but not square on the port, but only just
a very slight 'tweak' fxed.
My Spelling is Not Incorrect...It's 'Creative'
Thanks Steptoe,
I just went back out and did more investigating.
The reinforcing plate on top of the diaphragm was actually bent but you couldn't see it until the plate was removed from the diaphragm and a straight edge put across it.
The plate had bent inwards where the 4 screw holes are I was able to bend it back with my fingers with little force.
Also on top of the metering cone were 2 shim washers that were slightly bent, after having a good look these are there to act like a spring against the metal ring above them. So I bent them a little to give a bit more spring.
After reassembling the diaphragm, you could now feel the metering cone "grip" the inlet tube which wasn't doing before, hence the rich idle.
After restarting the engine I now could get it to stumble at both ends of the idle mixture adjustment screw, but now the diaphragm was resonating at idle and making a lot of racket.
So, I pulled the diaphragm back out and just gently pushed with my thumbs on the center of the reinforcing plate, reinstalled and everything was spot on.
I have a good quality idle and the idle mixture screw works a it should.
These impco mixers appear simple but they only need the slightest thing to be out of whack and they won't work properly.
Thanks,
Grant.
I just went back out and did more investigating.
The reinforcing plate on top of the diaphragm was actually bent but you couldn't see it until the plate was removed from the diaphragm and a straight edge put across it.
The plate had bent inwards where the 4 screw holes are I was able to bend it back with my fingers with little force.
Also on top of the metering cone were 2 shim washers that were slightly bent, after having a good look these are there to act like a spring against the metal ring above them. So I bent them a little to give a bit more spring.
After reassembling the diaphragm, you could now feel the metering cone "grip" the inlet tube which wasn't doing before, hence the rich idle.
After restarting the engine I now could get it to stumble at both ends of the idle mixture adjustment screw, but now the diaphragm was resonating at idle and making a lot of racket.
So, I pulled the diaphragm back out and just gently pushed with my thumbs on the center of the reinforcing plate, reinstalled and everything was spot on.
I have a good quality idle and the idle mixture screw works a it should.
These impco mixers appear simple but they only need the slightest thing to be out of whack and they won't work properly.
Thanks,
Grant.
Last edited by oz 300te on Thu Jan 03, 2008 10:16 pm, edited 1 time in total.
Cool had my fingers crossed it would be something like what I had on the 425..
Coupe the here guys pionted me in that direction a few weeks ago
To be honest I have only seen a 200 sitting on a shelf..never actually touched one.
Get Franz's manual m8...theres a couple links in other posts how to get it.
70 odd pages of good bottom line reading...once u get thru the 1st couple pages of intro...but every good manual has those lol
Cheers
Steps
Coupe the here guys pionted me in that direction a few weeks ago
To be honest I have only seen a 200 sitting on a shelf..never actually touched one.
Get Franz's manual m8...theres a couple links in other posts how to get it.
70 odd pages of good bottom line reading...once u get thru the 1st couple pages of intro...but every good manual has those lol
Cheers
Steps
My Spelling is Not Incorrect...It's 'Creative'
Update on this.
Looks like I was barking up the wrong tree with bending the washers (shims) on top of the metering cone and also thinking the plate was bent.
The idle went out of whack again and the stuttering of the air flap came back.
After re-reading the Impco catalogue and it states "Additional low speed idle mixture control can be obtained to lean air fuel mixtures through the use of optional shims." I then realised the shims shouldn't be bent.
So, I just pulled it apart again for the upteenth time and measured the shims and the total was .17mm, I had a .08mm shim from another 200 I bought off ebay, so I added this to give .25mm.
Reinstalled, Restarted and I can now adjust from lean to rich on the idle mixture.
Hopefully this helps anyone else who is having a similar issue.
Looks like I was barking up the wrong tree with bending the washers (shims) on top of the metering cone and also thinking the plate was bent.
The idle went out of whack again and the stuttering of the air flap came back.
After re-reading the Impco catalogue and it states "Additional low speed idle mixture control can be obtained to lean air fuel mixtures through the use of optional shims." I then realised the shims shouldn't be bent.
So, I just pulled it apart again for the upteenth time and measured the shims and the total was .17mm, I had a .08mm shim from another 200 I bought off ebay, so I added this to give .25mm.
Reinstalled, Restarted and I can now adjust from lean to rich on the idle mixture.
Hopefully this helps anyone else who is having a similar issue.
-
RichardKCMo
- Posts: 13
- Joined: Sun Nov 11, 2007 11:19 pm
impco 200?
What car and motor do you have this on?
I'm trying to find out what i need for my ford ranger.
RichardKCMo
I'm trying to find out what i need for my ford ranger.
RichardKCMo