Pontiac Owners Club UK

So, I bolted on my new ( reconditioned apparently nice for the website to make that clear) quadrajet, better than the old one but still idling at 3000 rpm, I can get it down to around 1500 rpm by moving the throttle by hand so it sits against the screw ( if that makes sense) but as soon as you rev it, it's back up the 3000,

the electric choke connector is broken so I assume that isnt helping, i was hoping if I left it to warm up the revs would drop down but it didn't,if i plug the connector to the front left of the carb in there is a fast relay click sound, the car starts if this is plugged in or not, there is another connector on that side carb which is burnt out, no idea!
Is there a way of bypassing the choke mechanism or am I gonna have to keep buying connectors until it hopefully does what it is suppose to?

Any help would be greatly appreciated, I have owned it since july, havn't driven it yet and has fought me ever step of the way!

Is get down to robin at Autopontiac - the off the shelf carbs are never set up to run 100% on a particular engine. Quadrajets are great carbs but require know how to set up which unfortunately I don't have but robin does! Made my run like a dream

Just worth checking - is the spring in the throttle lever strong enough to pull the throttle back to the screw after revving?

And idle mixture setting can be key in getting idle speed right. Too rich to a degree and it will Rev. If this is a reconditioned carb how come things are burnt out on it?

Its the connections to the carb or to do with carb not on the carb that are burnt out or broken, every I look at on the car has been bodged
even with the throttle cables off it won't return properly unless you move the the choke mechanism by hand so the front flap opens but as soon as you rev it you have to do the same again or it idles really high, just trying to order choke and mixture connectors from rock auto, but its just kicked me out as i was paying so am now waiting to see if I have to do it all again!
car is a project, hasn't been on the road since 2006 so I cant take it anywhere until it runs.

Trying to do it all myself if possible, to learn and also to keep costs down, although ordering a tenners worth of electrical connectors and paying £20 in postage just doesn't seem right!

To be honest the electric choke isn't necessary for running the car. Mine doesn't have a choke at all. When cold I pumpthe pedal before trying to start and once fired I keep the revs at around 2000 for 1 minute and then she idles nicely. However she is a 1980 and not computer controlled like yours.

If connectors are burned it suggests some serious electical fault and maybe the computer has been damaged?

It's great that your trying to do it all yourself by the way,

But sometimes it's often best to see a pro.

However, if you can sort out the choke by getting the bits, and sorting the burned connectors out you may have more joy with it. As far as I know the solenoid clicking when you connect the plug will be the idle solenoid for fuel mixture. The carb may just need a good setup once you get It running well enough to drive it somewhere

If it comes to it I will take it to get set up properly, I'm not gonna start playing with all the screws on the carb, that just leads to trouble!
can anyone suggest the best place to get electrical engine components and the like in the uk, or is it just ordering from the states and swallowing the postage?
I have noticed it is very difficult to find out any sensible information about the carb online without it degenerating into 10 pages of "bin it and fit a holley yee haw etc" not on here I hasten to add but general lee

Sorry, I forgot to say, I have tried contacting rocky about one of the many other issues with the car and he was quite difficult to get hold of, thanks for the reminder though I will probably end up giving him a call.

you can also give robin a call if u like at autopontiac he specialises in quadrajets.

yep I will have a chat with him when I get it a bit nearer to running, I am slowly gathering useful info on the carb and its various emission systems,
you were correct about the idle solenoid, what I didn't realise was it is supposed to do it!, next step is to try and retrieve the fault codes from the ecu doohicky under the dash!

To set up a Computer controlled Q jet:

the 2 idle mixture screws on the front bottom of the carb should be 3 and 3/8 turns out ( I did 3 turns then a little bit)
the idle air bleed on top of the carb, which has a hole in the middle, should be 3 turns out.
this will give a base line for later fine tuning.

on the choke side of the carb, looking down from the top, there should be a small lever, mine has a letter 'E' on it. pressing this down will switch off the choke and return the throttle flap things to the vertical position and the throttle stop thing should be resting on the idle speed screw
you now need a multi meter. there should be a 3 wire connector for the throttle position sensor on the front drivers side of the carb, with the ignition on, check the voltage between the middle and bottom wires. it should be 0.48V. of not there is a small, like 2 mm hex head screw just above the throttle lever ( it may have a metal plug over it) turn this ti adjust to the voltage I mentioned.
open the throttle flap and the front should snap shut(this is part of the vehicle starting procedure, to basicly activate the choke and provide an extra squirt of fuel into the carb)
run the engine till it gets to temp, press the choke deactivate lever to get the idle speed down (worry about fixing the choke later)
adjust the idle speed screw up or down to get it to 600rpm in drive(get a helper to hold the brakes on)

you now need a dwell meter, digital ones are cheap on ebay I think. hunt around the wire harness near the heater box where the harness disappears into the passenger wing, you should find a green connector. connect this to the + lead of the dwell meter on the 6 cylinder scale(I know it's a v8, but the solenoid cycles 60 times a second) connect the - lead to ground. the reading should fluctuate a bit showing the car is in closed loop and ecm is doing tis thing, if its a solid reading and the enging is fully warmed up you have issues. turn the idle bleed screw until you get a reading of about 30 in park. then re check the throttle position sensor.
then you are done. Oh and clicking is fine, means the mixture solenoid is working.

Sorry if this a bit long winded and maybe not explained very well. shouldn't take more than half hour once the engine is warmed up.

to check codes, under the drivers side dash, you'll find the diagnostic connector. connect the 2 on the upper row, far right together. bent out paper clip works good for this. turn ignition on. check engine light will flash to tell you codes, so a 42 would be 4 plashes, pause then 2 flashes. It does each code 3 times. it always starts and ends on a code 12. basicly that means the ecm is working.
hope this helps

for the throttle position sensor, you may need to make or buy a special tool as its quite a small one

Great info there!

Warlord, you sir are an absolute star!
only thing that may make a difference is mine is a manual, but I certainly have a lot more info to work with, thank you.

I had a bit of a play around yesterday, Idle is now down to 1200rpm so getting there!
The main problem now seems to be that even when you hit the lever to turn the choke off the throttle mechanism isn't sitting near the idle screw thing so turning it down doesn't do anything ,it is about half a cm away from it, even trying to move it by hand it just won't move far enough forward, I have turned the fast choke idle down under the choke but that didn't do much either I didn't manage to test the tps sensor but I assume this wouldn't make a difference ?
I am confused

The computer codes just read 12 3 times and then 12 3 times so no fault codes present?

Have you checked ignition timing? Should be 6 degree btdc.

That's with the 4 wire connector under the dizzy unplugged (disables computer advance)

Blue43 wrote:Sorry, I forgot to say, I have tried contacting rocky about one of the many other issues with the car and he was quite difficult to get hold of, thanks for the reminder though I will probably end up giving him a call.

Sorry not sure if you have been trying to contacts us but our phones have been ringing non stop so no problems there. My email is down at the moment though.

Hi, all, so after many months of ignoring car due to the weather and general disillusionment with the whole thing, I finally took the cover off and bolted the carb back on and connected it all up, turned it over, expecting another afternoon of head scratching, it instantly idled at 800 rpm! I can only assume that the base gasket wasn't seated properly the last 3 times its been on and off!

That's welcome news Steve.

Well that was short lived, started it up today, left it running for 10 minutes, bolted on air filter and shut bonnet to hear how it sounded, unscrewed air filter and revs instantly went up to 1200! Boooooh

Air leak somewhere maybe. Split vac pipe