Author Topic: 1977 Qjet coughs and sputters  (Read 10688 times)

Offline stushug

  • Garage guy
  • **
  • Posts: 19
Re: 1977 Qjet coughs and sputters
« Reply #15 on: June 17, 2017, 09:20:51 PM »
I purchased the SR kit, and redid the carb today. I got a little bit of improvement, but the car still won't run right. Now, if I go pedal to the floor, it still coughs and sputters until I back off the throttle to about 3/4 to the floor. The things I found wrong when I opened the carb were that the old float was partially disintegrated and the spring for the secondary plates was too tight. I'm not sure what to check next.

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5360
Re: 1977 Qjet coughs and sputters
« Reply #16 on: June 20, 2017, 04:41:21 AM »
Is that the only place you are having issues, going to full throttle?

Offline stushug

  • Garage guy
  • **
  • Posts: 19
Re: 1977 Qjet coughs and sputters
« Reply #17 on: June 20, 2017, 05:29:29 PM »
Yes. If traveling at lower speeds and I go wide open, the car starts to sputter, it has even stalled out a few times. As the rpms rise, it behaves a little better, but it never fully recovers. When it's acting like that, if I back off the throttle just a bit, the problem mostly disappears. As long as it's at full throttle though, the problem persists.  Thanks for the help so far, Cliff!

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5360
Re: 1977 Qjet coughs and sputters
« Reply #18 on: June 22, 2017, 01:49:43 AM »
Did you install the new secondary plastic cam and spring from the kit?

Offline stushug

  • Garage guy
  • **
  • Posts: 19
Re: 1977 Qjet coughs and sputters
« Reply #19 on: June 22, 2017, 04:08:54 PM »
Yes I did.

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5360
Re: 1977 Qjet coughs and sputters
« Reply #20 on: June 23, 2017, 01:25:52 AM »
I'd try making adjustments to the spring tension and see if it improves.
Also make sure the choke pull-off is holding the secondary flaps tightly shut at idle and no slop in the linkage.  The pull-off should open in about 1.5 to 2 seconds from compressed to fully open.  Also make sure that it is holding vacuum.....Cliff

Offline stushug

  • Garage guy
  • **
  • Posts: 19
Re: 1977 Qjet coughs and sputters
« Reply #21 on: June 24, 2017, 07:51:15 AM »
I checked the pull-off and the linkage is fine, it holds the flaps fully closed with no slop. It is holding vacuum, but I did see that when I applied throttle, it went from compressed to fully open almost instantly.
As far as the tension spring, I'm not sure where a good starting point would be so I'm not sure if I have it too loose or too tight. If I started at no tension, is there a number of turns or partial turns as a general start? Or maybe using clock numbers such as one or three o'clock from zero tension?

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5360
Re: 1977 Qjet coughs and sputters
« Reply #22 on: June 27, 2017, 05:00:38 AM »
but I did see that when I applied throttle, it went from compressed to fully open almost instantly.

It should open much slower, about 2-3 seconds from closed to fully open once you go to full throttle......Cliff

Offline stushug

  • Garage guy
  • **
  • Posts: 19
Re: 1977 Qjet coughs and sputters
« Reply #23 on: June 27, 2017, 03:05:58 PM »
Does that mean mine is bad, or is there a way to adjust it? If it needs replaced, I assume you sell them?

Offline stushug

  • Garage guy
  • **
  • Posts: 19
Re: 1977 Qjet coughs and sputters
« Reply #24 on: July 01, 2017, 12:10:23 PM »
but I did see that when I applied throttle, it went from compressed to fully open almost instantly.

It should open much slower, about 2-3 seconds from closed to fully open once you go to full throttle......Cliff
Does that mean I need to replace it, and do you have replacements? Thanks.

Offline blazer74

  • Carb lover
  • ***
  • Posts: 115
Re: 1977 Qjet coughs and sputters
« Reply #25 on: July 02, 2017, 10:26:43 PM »
Cliff has them. Bet it's been modified.

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5360
Re: 1977 Qjet coughs and sputters
« Reply #26 on: July 16, 2017, 03:18:20 AM »
Yes, we stock the good ones with a straight inlet so they are easy to modify....

Offline stushug

  • Garage guy
  • **
  • Posts: 19
Re: 1977 Qjet coughs and sputters
« Reply #27 on: July 23, 2017, 09:21:01 PM »
I purchased one of your pulloffs, installed it today and didn't notice any difference. With the car at full throttle, it keeps stuttering and backfiring. If I back off the throttle just a touch, the car accelerates much better.

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5360
Re: 1977 Qjet coughs and sputters
« Reply #28 on: July 25, 2017, 03:50:10 AM »
Do you have a restriction someplace in the exhaust system?

Your problem sounds fundamental and may not be related to the carburetor provided you have done a complete/correct rebuild with good parts and correct settings......Cliff

Offline stushug

  • Garage guy
  • **
  • Posts: 19
Re: 1977 Qjet coughs and sputters
« Reply #29 on: July 25, 2017, 05:26:39 PM »
Cliff,
The carb was just rebuilt by me after purchasing one of your SR kits about three weeks ago, then I changed the pulloff on Sunday, on your recommendation. The engine is a rebuild with about 3K miles on it, and the dual exhaust, from manifolds to tailpipe was installed right after the rebuild. There are definitely no restrictions there. I will go over everything again, but I have checked fuel pressure, vacuum lines, exhaust and engine timing multiple times. I'm running out of ideas. I appreciate your suggestions and will follow up. Thanks.