Auto Choke Stalls Car when it Auto Returns

Rotary Engine Chat......Got A Problem With Your Rotary Engine.... Need Help...?
tomsmy
Posts: 54
Joined: Sun May 22, 2016 12:55 am
Location: Alberta Canada (via Stoke on Trent, England)

Re: Auto Choke Stalls Car when it Auto Returns

Post by tomsmy » Thu Jun 09, 2016 5:36 am

Thanks for all the advice guys.

I now have some things to try over the weekend. I will keep you all in the loop on my progress and findings! Fingers crossed I get it sorted and can report back with good news.

Tom

tomsmy
Posts: 54
Joined: Sun May 22, 2016 12:55 am
Location: Alberta Canada (via Stoke on Trent, England)

Re: Auto Choke Stalls Car when it Auto Returns

Post by tomsmy » Sun Jun 19, 2016 1:21 am

Hey Guys,

So i finally got time to test all your suggestions. So here goes:

1) Installed new ignition coils (tested mine they were out of spec on resistance)
2) Installed new spark plugs (old ones had a slight yellow discolouration)
3) Installed new spark plug leads.
4)Turned on car and got up to temp (usual process with feathering out choke required)
5) Checked Idle speed (i was wrong in my previous post, she idles at about 1250 rpm when warm and choke back in).
6) As the car already was idling at ~1000 rpm i adjusted the mixture screw (clockwise) until she started "hunting" then backed it off about 3/4 to 1 turn until the idle was fairly smooth (it was still a little lumpy no matter how far i backed it off)
7) I then tried to reduce idle using the idle speed screw (the one by the throttle linkeage)however that's when i realized that no matter how far i turn it anti clockwise the idle wont drop below 1000 rpm.....

So based on the above I assume i have a vacuum leak?

i sprayed some carb cleaner around but couldn't find anything that made the motor slow indicating a leak.

Upon close inspection with a torch i noticed that several of the "caps" the previous owner used to block off tubes (when he removed the emissions stuff) are cracked and likely are no longer sealing things off.

Do you think a logical next step would be to replace all vacuum tubes and caps?

Thanks

Tom

tomsmy
Posts: 54
Joined: Sun May 22, 2016 12:55 am
Location: Alberta Canada (via Stoke on Trent, England)

Re: Auto Choke Stalls Car when it Auto Returns

Post by tomsmy » Mon Jun 20, 2016 2:22 pm

Did some more digging last night.....found a couple of the caps completely split.

Just ordered new ones and new vacuum lines - will be replacing them as soon as the parts arrive.

I feel pretty dumb as i really should have checked this sooner.

Will keep you all posted,

Tom.

User avatar
DKWW2000
Posts: 1210
Joined: Sun Jul 06, 2014 10:16 pm
Location: English Riviera - South Devon

Re: Auto Choke Stalls Car when it Auto Returns

Post by DKWW2000 » Mon Jun 20, 2016 2:31 pm

It is a matter of time & patience finding faults.
Someone once said " 'If you've eliminated all other possibilities whatever remains must be the truth" I think it was that Holmes fella.
That is a good thing about older cars, unlike all the ECU guff of today ;s; :lol: :lol:
RX7 FB S3 - RX7 FC TII Vert
Rotaries Previously Owned:-
2 x NSU Ro 80s - 2 x S2 RX7s - Suzuki RE 5 - DKW(Hercules) W2000 - Norton (Krauser) Commander

tomsmy
Posts: 54
Joined: Sun May 22, 2016 12:55 am
Location: Alberta Canada (via Stoke on Trent, England)

Re: Auto Choke Stalls Car when it Auto Returns

Post by tomsmy » Sun Jul 03, 2016 4:54 am

Hello All,

So the new vacuum hoses arrived and after some "car yoga" I managed to install them.
Attachments
New Vaccum Hoses (3).JPG
New Vaccum Hoses (3).JPG (236.64 KiB) Viewed 2079 times
New Vaccum Hoses (2).JPG
New Vaccum Hoses (2).JPG (221.39 KiB) Viewed 2079 times
New Vaccum Hoses (1).JPG
New Vaccum Hoses (1).JPG (152.11 KiB) Viewed 2079 times

tomsmy
Posts: 54
Joined: Sun May 22, 2016 12:55 am
Location: Alberta Canada (via Stoke on Trent, England)

Re: Auto Choke Stalls Car when it Auto Returns

Post by tomsmy » Sun Jul 03, 2016 5:06 am

Unfortunately, this has not fixed my issue.

The past few days i have made several attempts to lower the idle using the idle adjust screw and the mixture screw.

Here is what I have found:

1) It sure is hot under the hood when its 30 degrees C and the engine is running.....and man is the fan ever noisy!!!!

2) If i lower the idle from its happy 2000rpm it gets pretty rough and hard to smooth out. I managed to get it to about 1400rpm and reasonable smooth, however, when i apply the throttle it really hesitates/stumbles/bogs, the the point I would not trust it on the road. the only way i have managed to make the car driveable and to remove this bogging is to set the idle back to 2000rpm.

3) I tried carb cleaner and it had no effect (other than making the car stumble whilst spraying).

4) I have really looked hard and tried squirting carb cleaner all over the place to try to find a vacuum leak but to no avail.

So my next train of thought was to see if the throttle plates are sticking open, which would cause the idle to be high, right? So i had a look down the barrels and noticed that the primaries are squeaky clean and only open a hair when the engine is running (which the should be so it runs right?). The secondaries however are not as clean, i even found a dead fly in there......i removed the fly and took the following picture:
Attachments
Secondaries.JPG
Secondaries.JPG (168.19 KiB) Viewed 2079 times

tomsmy
Posts: 54
Joined: Sun May 22, 2016 12:55 am
Location: Alberta Canada (via Stoke on Trent, England)

Re: Auto Choke Stalls Car when it Auto Returns

Post by tomsmy » Sun Jul 03, 2016 5:16 am

So i was wondering if this level of dirt would be enough to make the secondaries stick open and cause my high idle?

However, if this is the case - if i adjust the mixture screw to the right (in, clockwise) which is leaner (i think!) then one would expect the car to stall? However this does not happen.....I turned the screw in until it stopped and the motor did not die.

So I checked the float levels, front a rear both seem ok (halfway up the glass).

The previous owner removed a lot of emissions stuff, which I am still trying to understand. One of them was the shutter valve, no vacuum hoses go here, i am ASSUMING that they set it to be permanently open.


So now I am wondering where to look next? The previous owner said they rebuilt the carb, but should i be pulling and rebuilding? Or are there other avenues i should check first?


Thanks

Tom

tomsmy
Posts: 54
Joined: Sun May 22, 2016 12:55 am
Location: Alberta Canada (via Stoke on Trent, England)

Re: Auto Choke Stalls Car when it Auto Returns

Post by tomsmy » Tue Jul 05, 2016 3:40 am

So I decided to check the accelerator pump to cross that off the list.

I took its cover off and the membrane looked like new (which makes sense if the previous owner did a rebuild).

I then wanted to check that its "pumping" properly. I read that you can manually activate it when the engine is off to see the fuel squirt.

However i am a little stumped how to do this?

I trued pushing the lever shown in the picture below but it barely moved and no fuel came out. Am I trying to work the wrong thing?

Thanks, Tom
Attachments
DSCF0455.JPG
DSCF0455.JPG (263.92 KiB) Viewed 2064 times

tomsmy
Posts: 54
Joined: Sun May 22, 2016 12:55 am
Location: Alberta Canada (via Stoke on Trent, England)

Re: Auto Choke Stalls Car when it Auto Returns

Post by tomsmy » Tue Jul 05, 2016 3:42 am

After doing this i double checked the float levels - the front is halfway but the rear is low (about 1/4) this was not the case yesterday. Did i press something to cause this? or perhaps this is the cause of all my issues?

Tom

codge
Posts: 2602
Joined: Fri Apr 01, 2011 11:41 am
Location: South Yorks.

Re: Auto Choke Stalls Car when it Auto Returns

Post by codge » Tue Jul 05, 2016 11:47 am

Easiest to check the accelerator pump by asking a friend to push the throttle pedal down quick.
Or from memory you can twist the quadrant on the carb spindle that the cable wraps around.

Post Reply