need a quadrajet expert

[jimski]

My quadrajet #17083244 is extremly erratic every vacumm plugged.everything hooked up correctly even a fresh rebuild same problem's.Will not idle, erattic idle.When i put my hand over the top slightly starts to idle higher like it is sucking air from somewhere.I installed my other unit which been using since day one from a 86, 307 freshly rebuilt by me idles perfect put my hand over the top of that carb and the engine dies out in other words it is working correctly like it should.

I would rather use the correct unit #17083244 for carbed hot air engine it seems to have a quicker throttle response then the 86" 307 carb
Plus the 17083244 carbs linkage geometry is perfect for the aplication.It has just been a pain in a as s. I adjusted everthing to speck tinkered with it also under a running condition still screwed up thou,what should i look for here.It is acting the same before and after a fresh rebuild..

Now the weird part about this whole thing is the carb i got from the forum the other day that was for sale the 17082244 is kinda doing the same thing
erratic idle,put my hand over the top seems to suck air from somewhere by idleing higher,The only difference in both the 17083244 and the 17082244 is the 1708244 that i got from the board the other day idles and dosnt die out but is eratic, but idle rises sometimes while driving creating an unsafe conditon 9lbs of boost even thou im off the pedal weird.I have to put car in nuetral and shut it off.Nothing is stuck either.

 

[Freddie's Buick]

97% of rebuilds by a first timer get goofed up. Q-Jets are not made for the average week-end warrior. Mis-adjustments don't cause erratic behavior, (rich/lean), it's always that one did something wrong.
The numbers don't help. Is it electronic or non-electronc?

What exactly did you rebuild internally? What was done to it? Rebuilds don't make much sense, (if it works prior to a dis-assembly leave it alone).

One should only rebuild a carb as a result of it not functioning.
Did it function well prior to the rebuild?

By the way, the carb #17083244 is an 83 turbo carb, (same as I have). So the problem may be electronic.

 

[jimski]

97% of rebuilds by a first timer get goofed up. Q-Jets are not made for the average week-end warrior. Mis-adjustments don't cause erratic behavior, (rich/lean), it's always that one did something wrong.
The numbers don't help. Is it electronic or non-electronc?

What exactly did you rebuild internally? What was done to it? Rebuilds don't make much sense, (if it works prior to a dis-assembly leave it alone).

One should only rebuild a carb as a result of it not functioning.
Did it function well prior to the rebuild?

They are electronic and i probally rebuilt about 23 of um or so in my life with success.They werent working right from the getgo this is why i chose the rebuild and internally clean um up inspect for bad floats ,clogged ports ect...They are both adjusted to spec even tweaked around with them in the running state could not cure there erratic behavior.

Does any 1 here want to take a look at um. Probally test them on there car to try and figure out why they suck air from somewhere.I even sprayed carb cleaner around carb to see where a possible leake could be and they passed.I know there sucking air from somewhere when my hand is placed lightly over the top the idle jumps intensly.

WEIRD SH IT going on.. The both turbo carbs suffer the same symtoms almost 17083244 plus the 17082244 these numbers represent the 1983 turbo carb and the 1982 turbo carb..

 

[Freddie's Buick]

...They are electronic and i probally rebuilt about 23 of um or so in my life with success...

If you rebuilt this one then it was not a success.:biggrin:

I've lost count of how many Q-jets I've worked on. When I first started back in 1975 my first failures were based on errors. And those carbs were super easy. The electronic ones were a major learning curve but now they are a hobbie for me.

Take your time. Do you have a digital multi-meter? Do you know basic electronic circuitry? Do you have a digital caliper? Do you have drill bits ranging from 61-80? Did you remove the idle tubes? Did you measue the MCS primary needles and adjust them to 1.304"?

The number #1 goof up on electronic carbs is on the air horn.
Some folks start messing with the air bleed valve on the air horn and screw it up. Then to top it all off they finish it by jamming the MCS plunger on the air horn gasket.

I have repaired many a 'goofed-up' rebuild by others and found that these are the primary areas folks messed up on.

The final tool in your asenal should be these two books; 'Rochester Carburetors' by Doug Roe, and tweaking knowledge from 'Rochester Quadrajet Carburetors' by Cliff Ruggles.

I don't care how many successes one has. Without those tools and those books you'll always be at a handicapped.

If you are 100% sure it's not the carb you rebuilt and you feel confident about it, then the answer is self-explained...it's not the carburetor.

I would look for a manifold leak elsewere.

Good luck!

 

[charlief1]

I'm with Freddie on this one.

You can rebuild the carb all you want but if you don't know how to mod it or at least set everything properly it's a no go. I have no idea of how many I've done over the years but if you don't have the books and the right tools you shouldn't do it. If the 307 carb is working on the engine I'd put it on for now. Internally there's not much difference on the E4ME carbs. As Freddie said "The number #1 goof up on electronic carbs is on the air horn.
Some folks start messing with the air bleed valve on the air horn and screw it up. Then to top it all off they finish it by jamming the MCS plunger on the air horn gasket."
It is the #1 prob on them when you don't know what you're doing. Not trying to be mean, just realistic.
As far as the idle you might want to check the idle solinoid on the carb. If it's bad it would cause an irratic idle as well.

 

[jimski]

If you rebuilt this one then it was not a success.:biggrin:

I've lost count of how many Q-jets I've worked on. When I first started back in 1975 my first failures were based on errors. And those carbs were super easy. The electronic ones were a major learning curve but now they are a hobbie for me.

Take your time. Do you have a digital multi-meter? Do you know basic electronic circuitry? Do you have a digital caliper? Do you have drill bits ranging from 61-80? Did you remove the idle tubes? Did you measue the MCS primary needles and adjust them to 1.304"?

The number #1 goof up on electronic carbs is on the air horn.
Some folks start messing with the air bleed valve on the air horn and screw it up. Then to top it all off they finish it by jamming the MCS plunger on the air horn gasket.

I have repaired many a 'goofed-up' rebuild by others and found that these are the primary areas folks messed up on.

The final tool in your asenal should be these two books; 'Rochester Carburetors' by Doug Roe, and tweaking knowledge from 'Rochester Quadrajet Carburetors' by Cliff Ruggles.

I don't care how many successes one has. Without those tools and those books you'll always be at a handicapped.

If you are 100% sure it's not the carb you rebuilt and you feel confident about it, then the answer is self-explained...it's not the carburetor.

I would look for a manifold leak elsewere.

Good luck!

Fred youre right these 2 where not a success
They both suffer the same symptom how odd, im begining to think there is actually a difference in the n.a carb -vs- the 2 turbo quadrajets(17083244)-(17082244).The 307 olds carb runs perfect.The only problem is that the geometery is off on the linkage .I rebuilt that one with great success even changed the throttle plate bushings with new ones.Works perfect which rules out manifold leaks.

 

[jimski]

Fred do u want me to send you the 17082244 turbo quadrajet so u can possibly hook it up to youre car to see what i mean, this one was untouched by me and was rebuilt by holley..and is like new.I got it from the sight the other day it acts the same as the 17083244 i got from bison a while back.How could 2 turbo quadrajets have the same symtoms but yet when i put the 307 carb on works perfect.Keep in mind i never even took apart the 1982 one that was rebuilt by holley so this rules out human error if u ask me.

 

[Freddie's Buick]

....Fred do u want me to send you the 17082244 turbo quadrajet so u can possibly hook it up to youre car to see what i mean,

Wish I can help you out there bro but my time is severely limited.

You did write that the 307's carb works good but that the linkage is not a match? Try swapping out the throttle plate on the 307 carb with the '82 Buick carb as a temp fix.

I agree that the 83 carb is the best suited to your set up. So store it until you can get it right. You could farm it out to Cliff's Q-Jet, (master carb dude), but that may run you some serious cash. (Personally I don't trust rebuilds but I'd bank on Cliff). You can save much moola doing it yourself though.

If you succeed in swapping out the throttle plate and it works right, then you'll have a good running car and you can go ahead and disect the 83' carb. But take your time. Before tearing it apart I'd run some test on the electronic parts.

Charlie's suggestion about the MCS selonoid is dead on. It is the heart of the mixture control system on the electronic carbs. That's were a digital meter comes in and resistance checks are important.


Yes the turbo carbs are slightly differant than an N/A carb. But the major differance is on the throttle linkage. It's made for a quicker secondary opening response. The rest is that they are tuned differantly.

 

[jimski]

Wish I can help you out there bro but my time is severely limited.

You did write that the 307's carb works good but that the linkage is not a match? Try swapping out the throttle plate on the 307 carb with the '82 Buick carb as a temp fix.

I agree that the 83 carb is the best suited to your set up. So store it until you can get it right. You could farm it out to Cliff's Q-Jet, (master carb dude), but that may run you some serious cash. (Personally I don't trust rebuilds but I'd bank on Cliff). You can save much moola doing it yourself though.

If you succeed in swapping out the throttle plate and it works right, then you'll have a good running car and you can go ahead and disect the 83' carb. But take your time. Before tearing it apart I'd run some test on the electronic parts.

Charlie's suggestion about the MCS selonoid is dead on. It is the heart of the mixture control system on the electronic carbs. That's were a digital meter comes in and resistance checks are important.


Yes the turbo carbs are slightly differant than an N/A carb. But the major differance is on the throttle linkage. It's made for a quicker secondary opening response. The rest is that they are tuned differantly.

Thanks for the reply, I swicted out the mcs selenoid with the one from the 307 still same thing i even put the throttle position sensor from the 307 in there...I have rulled out everything.I was thinking of just swapping the throttle plate and be on my way...Well see, i made a few calls today around town seems we have an expert on the situation down here.He wants to mess with it while running to see if he can narrow down it's troubles.Ill post back with the results.Thanks all.

 

[jimski]

Charlie would u like to take a look at the carb to see what i mean..
Ill send the carb rebuilt by holley it is like new..I never even pulled it apart.I rebuilt the 17083244 i got from bison same symtom's weird even before and after the overhaul.I even put the mcs and tps from the 307 carb to the 17083244 still the same thing..U think u have time to diagnose the 17082244 for me..The erratic idle i think is coused by it sucking air somewhere..When my hand is placed over the top idles jumps right up.when in fact the car should die out.It shares the same symtom's as the 17083244 i got from bison.


I f u figure this carb out i may be able to fix the other..

 

[dr_frankenstein]

umhmm........... 2 points for the Holley.

LMAO

A.j.

 

[jimski]

Think i figured this out why both turbo carbs almost act a like. I think i have a lean condition due to the metering rods in the turbo quadrajet's being to small for the 84 cutlass ecm to compensate them to the engine.The 307 carb clearly has larger metering rods and operates perfect with the 1984 ecm..when the turbo quadrajets are hooked up on the engine they are very erratic and the idle sucks big time.

Heres another question do u guys think i could put the 307 carbs metering rods in the 83 turbo quadrajet carb or should i just shoot for an 83 turbo ecm.It has been so long i cant find the original ecm i had in the garage.


http://www.florida4x4.com/tech/quadrajet/qtune.pdf


heres a good site page 4 tech tip 3 it explains why idle changes when hand is placed over the carb..

 

[charlief1]

Think i figured this out why both turbo carbs almost act a like. I think i have a lean condition due to the metering rods in the turbo quadrajet's being to small for the 84 cutlass ecm to compensate them to the engine.The 307 carb clearly has larger metering rods and operates perfect with the 1984 ecm..when the turbo quadrajets are hooked up on the engine they are very erratic and the idle sucks big time.

Heres another question do u guys think i could put the 307 carbs metering rods in the 83 turbo quadrajet carb or should i just shoot for an 83 turbo ecm.It has been so long i cant find the original ecm i had in the garage.


http://www.florida4x4.com/tech/quadrajet/qtune.pdf


heres a good site page 4 tech tip 3 it explains why idle changes when hand is placed over the carb..

Usually the change in idle is because of lack of fuel. On a Q-Jet the clicking noise is the primary fuel circuit off idle. It does effect the idle some but if you could push down on the solinoid you would see it's a little easier to set the mix screws. At idle the 2 screws at the front of the carb are what you have to count on. How far are they screwed out right now? The MCC solinoid is clicking when it's idling isn't it? As far as changing the needles out of the 307 carb you'd also have to change the jets as well and it takes a special socket or a LOT of patients.
Sorry, I'm just a litte brain dead tonight, been a long day and I just got home about 20 minutes ago. I still have to go check on 2 projects tonight so I'm doing a browse through me email right now. Put what you've done to the car in your sig cause I get confused sometimes with everyones cars. I don't remember what exactly you did.:redface: Sorry.

And for Aj, he's talking about a rebuilt Q-Jet from Holley, not a Holley.:tongue: :tongue: :tongue: :tongue: :tongue: :tongue: :tongue: :tongue:

 

[Freddie's Buick]

Since we're talking about electronic carbs the primaries are generally the same size and swapping them out won't make any difference. If he's talking about the secondaries it won't matter either. The secondaries won't be the same size from one car to another since they're tuned differently. Swapping them out would only make a difference in tuning not how it runs at idle.

The MCS delivers a fixed ratio if the primaries are set to "1.304 as it should be. Messing with the idle screws will create havoc in other throttle conditions. They have to be calibrated by the book or the ECM will throw a code. Nor will it allow for much leeway. In general, 2-1/2 to 3-1/2 turns out from a closed position is acceptable.

Most of the ECM's on the 82's on up share the same chip. So they are not at all that much different. They were tuned to run lean. I'm surprised Jimski's car isn't throwing some kind of code. At idle most of the electronic Q-Jets run erratic anyway. The MCS is controlling the rich/lean condition. The two sensors that send info to the ECM are the TPS and the O2 sensor. Once this info is received by the ECM and processed, it sends a signal to the MCS which controls the carb.

What gets me with Jimski's case is that if he chokes the carb it still runs. A classic case of vacuum leakage somewhere. When this happened to me I thought it was the carb too. But after exhausting my knowledge of carbs and hitting a brick wall I gave up. Only to find out the very next day that the leakage was at the EGR. The diaphragm in the EGR was busted and it was sucking wind through it.

 

[jimski]

Since we're talking about electronic carbs the primaries are generally the same size and swapping them out won't make any difference. If he's talking about the secondaries it won't matter either. The secondaries won't be the same size from one car to another since they're tuned differently. Swapping them out would only make a difference in tuning not how it runs at idle.

The MCS delivers a fixed ratio if the primaries are set to "1.304 as it should be. Messing with the idle screws will create havoc in other throttle conditions. They have to be calibrated by the book or the ECM will throw a code. Nor will it allow for much leeway. In general, 2-1/2 to 3-1/2 turns out from a closed position is acceptable.

Most of the ECM's on the 82's on up share the same chip. So they are not at all that much different. They were tuned to run lean. I'm surprised Jimski's car isn't throwing some kind of code. At idle most of the electronic Q-Jets run erratic anyway. The MCS is controlling the rich/lean condition. The two sensors that send info to the ECM are the TPS and the O2 sensor. Once this info is received by the ECM and processed, it sends a signal to the MCS which controls the carb.

What gets me with Jimski's case is that if he chokes the carb it still runs. A classic case of vacuum leakage somewhere. When this happened to me I thought it was the carb too. But after exhausting my knowledge of carbs and hitting a brick wall I gave up. Only to find out the very next day that the leakage was at the EGR. The diaphragm in the EGR was busted and it was sucking wind through it.

No codes or check engine light appear..If i uplug the tps or the mcs bing check engine light..It is working perfect and retarding knock like it should.

As per egr checked that too solid no air leaks,I put the 307 carb on from an 86 regal works like a champ ,but like u say in a few post above that carb is slower to open secondaries and even when gas is pressedit is slower in that aspect also and when my hand is placed over the horn the car dies out.(like it should).I try both turbo carbs and it is like night and day -vs- the 86 307 carb. Put my hand over the horn idles higher, both units.Very erratic idle.
car dies out sometimes on one carb..Im puzzled right now.

Have u seen thast pdf above? In one paragragh it states to detect a lean condition place palm over the horn if the quadrajet idles higher it is a definate lean condition..

 

[jimski]

Usually the change in idle is because of lack of fuel. On a Q-Jet the clicking noise is the primary fuel circuit off idle. It does effect the idle some but if you could push down on the solinoid you would see it's a little easier to set the mix screws. At idle the 2 screws at the front of the carb are what you have to count on. How far are they screwed out right now? The MCC solinoid is clicking when it's idling isn't it? As far as changing the needles out of the 307 carb you'd also have to change the jets as well and it takes a special socket or a LOT of patients.
Sorry, I'm just a litte brain dead tonight, been a long day and I just got home about 20 minutes ago. I still have to go check on 2 projects tonight so I'm doing a browse through me email right now. Put what you've done to the car in your sig cause I get confused sometimes with everyones cars. I don't remember what exactly you did.:redface: Sorry.

And for Aj, he's talking about a rebuilt Q-Jet from Holley, not a Holley.:tongue: :tongue: :tongue: :tongue: :tongue: :tongue: :tongue: :tongue:

The hardened caps are still on one of them And the other holley must have removed them but painted them in the position they are supposed to be in, but i quickly fixed that tinkering with it.Altimatly i put them back in the same exact position after there was really no difference in the way the carb was acting.. after adjustment.

Im just really weirded out about how 2 "turbo" quadrajets are acting.. alike.

 

[turbo nasty]

Pick up this months Car Craft they have a good write up in the QJ

 

[jimski]

Pick up this months Car Craft they have a good write up in the QJ

Thanks for a reply I have it, and also read it a while ago in in chevy high performance.Almost the same article.

http://www.chevyhiperformance.com/techarticles/0709ch_1984_chevy_camaro/photo_11.html

 

[Freddie's Buick]

......Have u seen thast pdf above? In one paragragh it states to detect a lean condition place palm over the horn if the quadrajet idles higher it is a definate lean condition..

It says cup it and it's a momentary thing. Anyway we're talking apples and bananas here. That write up and everything else I've read never deals with electronic carbs unless it's the Delco Remy. The only one I know of that does is Doug Roe's book. And even that left huge gaps of information missing.

Nope....none of the stuff in those write-ups apply to a CCC carb. They are unique. Racers and tuners hate them because the're too complex to figure out. They are not good for racing because one has limited control over them.

I will share with you this electronic 1981 Q-jet manual. It is more complex then the Roe book. But the information is accurate. And trust me, the only differance between the year and model vehicle of the CCC carb is what I previously wrote. TUNED DIFFERANTLY!!! With the exception of the electronic turbo carb which has shorter secondary linkage.

 

[Freddie's Buick]

...I will share with you this electronic 1981 Q-jet manual.....

Can't...it's too big.