i hate dualjet carbs (going to 4.1 intake very soon)

[MY85pontiac]

well this is it. in the next week or two (hopefully next weekend, i didnt have time to plan it for this weekend) i will have the 4.1 intake/carb put on the 3.8. the dualjet has given me a headache for the last time. i fought with this thing for like 3 hours today and i've had it. its like putting bandaids on a broken leg, the carb kits can only do so much, it cant fix the noticably loose throttle shaft though.


this carb is simply driving me insane! on a warm day (like 80 degrees) this SOB wants to bog, stall and die (its died on me twice last week) on me if i dont granny the pedal until the engine gets good and hot, yet in cold weather it wants to run like its on smack and speed. the carb has outlived is usefulness and will be joining the wonderful world of paperweights and boat anchors within two weeks (hopefully one).

 

[78Buick]

Do you still want me to get that 4.1 intake? I haven't had a chance lately to get to the yard, but can go sometime soon.

 

[Freddie's Buick]

Not to upset you or anything......but I have'nt seen a Duel-Jet that could'nt be fixed. All it is is a 1/2 a Q-Jet. If you get the bigger carb and intake remember.....lot's of parts are interchangeble with the Duel-Jet.

These electronic carbs are not easy to tinker around with. Onced opened if you think it's like opening up the old type GM non electronic carbs your in for a big surprise. The sad thing is that most mechanics think they can handled it and wind up screwing it up.

Be careful......keep the old carb and practice with it. Get Doug Roe's book 'Rochester Carburetors'. I've torn apart three Q-Jets and four Duel-Jets. Some I leave sitting forever in the rain and mud, rusty or full of crud. A couple of days later they were installed on Pontiacs, Regals or Cutless Supremes and ran as if they just came off of the assembly line.

 

[Ttype83]

Originally posted by Freddie's Buick
Some I leave sitting forever in the rain and mud, rusty or full of crud. A couple of days later they were installed on Pontiacs, Regals or Cutless Supremes and ran as if they just came off of the assembly line.

I'm going to mail you my spare hehehe

 

[MY85pontiac]

no i wont be needing the 4.1 intake anymore but thank you kindly anyway.



this dualjet has just seen better days. since i "fixed" it yesterday it runs much better but the throttle shaft is my main concern. it is LOOSE and i dont think that's normal or "within specs". thats half the reason. the other half being doing this swap would be cheaper than buying a rebuilt dualjet.


i just dont enjoy tearing it apart for something as stupid as an accelerator pump within two years. the first time i replaced it also removed the guts and cleaned it out (it was clean anyway, amazingly clean, like brand new clean) and checked the needle and seat assembly (looked like new), mixture solenoid, fuel bowl, float level (perfect), etc. i guess the part about this that really irks me is i pay like 35 bucks for a carb kit just to replace the accelerator pump (and WHY cant they include a new spring and clip with it? are these somehow hard to make items?!?!?!?!) and i now own two ALMOST complete carb kits for dualjets plus an almost complete gasket kit.

i already took the q-jet apart last night and gave it a visual inspection (everything looked good) then i cleaned it inside and out today with berryman carb cleaner. it looks good now and everything on it looks fine (it was rebuilt a few months prior to me buying the car {i have the receipt to it and the carb does look like its rebuilt and pretty well too}) so all i need is a TPS (mine somehow chunked a part when i took it apart and i couldnt find it! oh well no biggie, its JUST 30 bucks!), carb kit (like 18 bucks from autozone) and an accelerator return spring and its ready to go!

i'm repainting the air cleaner (i did a horrible job the first time) and its coming along nicely. i painted the lid today and its looks spectacular! the base is still being stripped clean (i do everything the hard way and do it with my two bare hands and 80 grit) and will be primed and painted soon. the intake will be yanked off either tommorow or monday, stripped (the previous owner painted it ford blue along with the long block) and cleaned then painted semi flat black (it'll match the 85's engine nicely).

i also have to replace the thermostat (i have no idea how old it is and im not taking chances on a part that only costs three bucks to replace) and yank the 4.1 fuel line and then i should be ready for the swap. its looking like its going to happen in two weeks. i WAS going to order a holley powershot air filter but i have a free unused throw away here so i might as well use it and save the money for the powershot filter later.

i think i've pretty much covered everything there is to cover except for the EGR and it was replaced not too long before i bought the car (he also had an air pump installed so i'll use that too, its practically brand new). if anyone else can mention anything i might have overlooked let me know.

i'll also be getting the car checked for emissions and timing at the same time (i think the timing is off a tad and i'm having the emissions checked to make sure i WILL pass next time).





oh btw, since i "fixed" the dual jet yesterday when i turn the car off it wants to keep running, like its dieseling. its not overheating and it doesnt do this everytime. the only thing that was replaced was the accelerator pump and the top gasket, thats it. nothing was adjusted changed or anything. any ideas what it might be? i think it might be related to the cool air we've been having at night (thats when it does it).

 

[Freddie's Buick]

Hey Jimbo.....

It's a labor of love dude.....

That's why I always have spare carbs......screw one up and I always have another. Got plenty of practice till I got it right. I sympathize for the Pontiac dude...... Been there. Curious about that pump problem he mentioned though.

I've got about five pumps and I never had that happen. They're all old but today I put one into my turbo carb. After I removed the TPS plug and opened up the shooters a bit, I cut down the secoundary air valve from 70 to 90 degrees. Shaved off about 1/32 of the pump rod and put her back on. Took off my '82 and this time I put it in a plastic bag, (got tired of cleaning it).

Welp.... no complaints! It runs very crisp. Still my launch is pure Regal. Too tired and too broke to put on a better T/C.

 

[MY85pontiac]

well i found out why the engine is idling so high,(it would diesel when i shut it off). the stupid ISC is acting wonky! dont ask me how, i dont know, i unplugged it and plugged it back up and now the idle is back down where it should be. i think the carb is trying to tell me something......like "get rid of me!" running at 1500 RPM at "idle" when the engine is already at operating temp is a pretty bad problem. thank god i dont have to put up with this carb much longer.

BTW what else besides turning on the a/c will cause the ISC to bump up the RPM? my a/c doesnt work and SOMETHING had to make the plunger come out and raise the RPM, it didnt do that on its own (or is my carb cursed???? )

its acting normal now but the throttle shaft is about the only complaint i have now (more loose than my 6 year olds font tooth). i also think the choke is a smidge out of adjustment but i can live with that.



i realize its only half a q-jet but i have always maintained it was the WORST half of the q-jet. and lets be honest 4 bbls are more fun than 2 bbls (they are to me anyway)