Author Topic: Buying used,older qjet for an 86?  (Read 5592 times)

Offline soonertank

  • Garage guy
  • **
  • Posts: 6
Buying used,older qjet for an 86?
« on: April 20, 2012, 09:23:44 AM »
Hi, I'm looking into replacing my stock M4MED qjet for something less electrically complicated.  Trying to clean up my eingine bay also. ;)
Anyway I found a couple used qjets and need to know about them before I try and buy them.

The codes are 17056502 and 17080213.

Which one would be better suited for my 86? My 86 has an auto trans (TH400 to be replaced by 700R4), and a 4.3 v6, power brakes and steering, cruise control.

Offline Ethan1

  • Moderator
  • Qjet Hero
  • *****
  • Posts: 1148
Re: Buying used,older qjet for an 86?
« Reply #1 on: April 20, 2012, 10:01:28 AM »
Hi, I'm looking into replacing my stock M4MED qjet for something less electrically complicated.  Trying to clean up my eingine bay also. ;)
Anyway I found a couple used qjets and need to know about them before I try and buy them.

The codes are 17056502 and 17080213.

Which one would be better suited for my 86? My 86 has an auto trans (TH400 to be replaced by 700R4), and a 4.3 v6, power brakes and steering, cruise control.

 17056502 is from '75-'76 Chevrolet El Camino 350cid/400cid and GMC Sprint 350cid/400cid A/T.

 17080213 is from '80-'85 Chevrolet Truck 350cid and GMC Truck 350cid Non-California M/T.

 As for which one is best, I'm not sure. Cliff will know which one is best. :)
Ethan

1972 Chevelle

(oo______oo)

Offline soonertank

  • Garage guy
  • **
  • Posts: 6
Re: Buying used,older qjet for an 86?
« Reply #2 on: April 20, 2012, 10:41:47 AM »
What's involved using a M/T carb in a A/T vehicle?

What all change from the 85 to 86 Chevy qjets?

Offline Ethan1

  • Moderator
  • Qjet Hero
  • *****
  • Posts: 1148
Re: Buying used,older qjet for an 86?
« Reply #3 on: April 20, 2012, 02:53:06 PM »
What's involved using a M/T carb in a A/T vehicle?

What all change from the 85 to 86 Chevy qjets?

 I don't believe there is any significant difference between a M/T Qjet and a A/T Qjet. Maybe some linkage is different, but I believe it will be a direct bolt on.

 As for your other question, I don't believe there were any big changes. What is the date code on the 1708 carb? That carb may be from an earlier year.

 Like I said, Cliff will have better answers. I like the 1705 carb, because of no electric hook-ups. Like MCS and TPS.
Ethan

1972 Chevelle

(oo______oo)

Offline soonertank

  • Garage guy
  • **
  • Posts: 6
Re: Buying used,older qjet for an 86?
« Reply #4 on: April 20, 2012, 08:43:27 PM »
Ya, me too. Got another lead on a qjet. #17066558 Any details on this one?
« Last Edit: April 20, 2012, 08:49:33 PM by soonertank »

Offline Ethan1

  • Moderator
  • Qjet Hero
  • *****
  • Posts: 1148
Re: Buying used,older qjet for an 86?
« Reply #5 on: April 21, 2012, 08:15:46 AM »
Ya, me too. Got another lead on a qjet. #17066558 Any details on this one?

 17066558 is from '80-'85 Chevrolet and GMC Trucks 454cid Non-California A/T.

 That looks to be a later model Qjet. Not sure if it has the electrical hook-ups or not.
Ethan

1972 Chevelle

(oo______oo)

Offline Ethan1

  • Moderator
  • Qjet Hero
  • *****
  • Posts: 1148
Re: Buying used,older qjet for an 86?
« Reply #6 on: April 25, 2012, 09:03:54 AM »
Hi, I'm looking into replacing my stock M4MED qjet for something less electrically complicated.  Trying to clean up my eingine bay also. ;)
Anyway I found a couple used qjets and need to know about them before I try and buy them.

The codes are 17056502 and 17080213.

Which one would be better suited for my 86? My 86 has an auto trans (TH400 to be replaced by 700R4), and a 4.3 v6, power brakes and steering, cruise control.

 Which one do you think would be better for his application, Cliff?
Ethan

1972 Chevelle

(oo______oo)

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5363
Re: Buying used,older qjet for an 86?
« Reply #7 on: April 26, 2012, 04:00:06 AM »
Neither one is really any better, same end result if set up exactly for the application.  The manual trans carb may not have a provision for a TV cable if one is needed.  Both can be set up for electric chokes.

The little 4.3 V-6's had carbs set up with no idle bypass air, and very conservative jetting from what I can remember.

In any case, I'd use the carb in the best shape, and set it up exactly for where it's going to end up.....Cliff

Offline soonertank

  • Garage guy
  • **
  • Posts: 6
Re: Buying used,older qjet for an 86?
« Reply #8 on: July 24, 2012, 10:25:47 AM »
OK, I found and bought a used qjet. #17057204 Got it for $20. I'll have to swap out the jets and metering rods for my v6. What size do you guys recommend for a 4.3 engine?

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5363
Re: Buying used,older qjet for an 86?
« Reply #9 on: July 25, 2012, 04:51:52 AM »
That's a large main airbleed model, I'd start out with the stock jetting, as they are pretty lean right to start with.  We sell every jet number for them, and metering rods if you need to lean it down even more?.....Cliff

Offline soonertank

  • Garage guy
  • **
  • Posts: 6
Re: Buying used,older qjet for an 86?
« Reply #10 on: July 25, 2012, 01:10:57 PM »
Sorry, I'm still learning (got your book on the way, should be here Saturday!) so I may not have understood what your saying. 

I'm going to put the older 1977 #17057204 carb on my 86 Chevy truck with a 4.3 liter engine. Your saying that the stock jet for that carb will be a good starting point for my engine? And what do you mean by "large airbleed model" ? Is the carb no good?

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5363
Re: Buying used,older qjet for an 86?
« Reply #11 on: July 26, 2012, 04:53:31 AM »
Nothing wrong with them at all.  Starting in 1970, the Chevy q-jets showed up with large main airbleeds, and revised calibrations for emissions.  They used them until the single main airbleed models were produced.  Having large main airbleeds, they tend to be lean at part throttle, so I'd start out with the stock jets and metering rods, do some testing, and upgrade if/as needed.....Cliff

Offline soonertank

  • Garage guy
  • **
  • Posts: 6
Re: Buying used,older qjet for an 86?
« Reply #12 on: July 26, 2012, 03:43:49 PM »
Ok, thanks Cliff. Can't wait to tackle it!