[Wynkerdink]

I'm having some trouble with my '67 GTO. I picked it up about 2 months ago and I'm having trouble getting it to run the way it should. I'm no expert, but after a lot of searching it looks like a lot of people here are. Any help would be appreciated.

Here's what we're working with. I picked up the car a couple months ago and very little info has been provided by the former owner. It has a 400 possibly bored out at one time. It seems as though there is a mild cam in it. It has the points ignition and a '69 Pontiac QuadraJet Carb.

It runs ok now, seems to be missing slightly though. Holding steady at any speed it has a slight hiccup every couple seconds. When you put your foot down it seems to have plenty of power once it revs up, but the power is inconsistent through the RPMs. After it hits ~3500 it "kicks in" and the motor really starts to scream. After 2nd gear hits the motor sometimes will cut out for a second and I'll feather the throttle to bring it back. Usually it's just the one cut out and it comes back pretty quick.

Here's what I've done so far. I took it to my local mechanic to check the timing. We discovered there were 12 volts going to the points. So he re-wired it so the resistor was actually being used. Then attempted to time it. That's when we discovered there's no timing indicator on the timing cover. He did the best he could to find TDC and mark it on the timing cover to use that as a reference point for timing. I also threw a carb kit in for good measure.

That's where I'm at now. I'm thinking my next step is to replace the ignition. Get rid of the points and go with something like the GME29 Breakerless Ignition on page 59 of the Performance Years catalog (vol. 11D). But in order to time it properly I'll also need a timing cover. The water pump is the 11 bolt so I'm guessing that was upgraded and I'll need the GME39C 1967-77 timing cover case. And while I'm at it, I was thinking of replacing the carb. Only I have no idea what would work best or how many cfm I'll need.

Before I start dropping money on parts I *think* will work, I was hoping someone would be able to give me some advice on where to go from here and if there are any recommendations as to what parts are the best. Thanks in advance for any help.

[Socrates]

First off, will you be doing the work with parts swapping and tuning yourself, or will a shop be turned loose with your credit card? While the first response of a newbie is to throw money and new parts at a problem, most problems have a simple tuning cause at their root that, without extreme luck, shiny new out-of-the-box parts will not cure, at least not without tuning of their own. If you are lucky enough to find a mechanic that can and will work on an old car, he might only be familiar with a limited set of parts and want to put his favorite ignition and carb in play to get a good tune, which is fine. On the other hand, if you get your own hands dirty and have the time to spare, you can likely tune what you have just a well and possibly get the car running great with little to no money spent.

Your "hiccup every couple seconds" sounds like a lean cruising surge. This could be related to too much advance, perhaps from the vacuum advance, or too lean of a fuel mixture, with the former being the best place to start. I'd start with simply disconnecting and plugging the vacuum advance can and retesting to see if the problem goes away. The timing curve is of course crucial to a good tune and good performance. I've never come across an early Pontiac engine without a timing tab. Could you post a pic of your current cover and maybe get us the engine and head codes to find out exactly what engine you have here, and even the Q-jet id number as well to help with tuning here? With a little creativity you could add your own or add a new cover with an existing tab. This should be where you start, along with buying your own timing light, even a cheap one, long before buying a new carb or new distributor.

As to this issue "When you put your foot down it seems to have plenty of power once it revs up, but the power is inconsistent through the RPMs. After it hits ~3500 it "kicks in" and the motor really starts to scream" I'd guess your have the infamous Quadrajet Bog and the Q-jet secondary air flap tension needs adjusting. The secondary flap tension is set by a set screw and an adjusting screw on the passenger side rear of the carb. Set it to where just closes on its own then add another full turn on the screw and retest. If it still bogs, try subtracting 1/8 turn of tension (max!) and retesting to see if the problem goes away, repeating the process as needed. A good book on Quadrajets from Doug Roe or Cliff Ruggles would make you life easier here and walk you through this with pics and longer descriptions. Jim Hand's book on Pontiac engines is also essential reading for beginners. You could also search here for "quadrajet and bog" and get a few days worth or reading material from this site alone.

[Old Goat 67]

Good analysis Socrates.

I was trying to formulate a competent response, but you beat me to it.

Could be many things, but those are the two best places to start.

Is this your first Pontiac? Could you please post pics of what Socrates asked for. Lots of times it is just a simple adjustment.

Charles

[Wynkerdink]

I wouldn't mind getting my hands dirty. I have some experience with Chev 350s from back when I ran demolition derby cars. This isn't exactly a derby car though and I don't want to screw anything up too bad. I do have a friend who knows what he's doing. He's currently borrowing a QuadraJet book to read up on tuning them. The only problem is that he's an hour away and works shifts, so planning a weekend can be hard.

I have pics of most of the numbers, but of course they aren't on this computer. I'll have to post them later.

I'll see if I can get home early enough to plug the vacuum advance and give it a try. Maybe even stop by and pick up a timing light on the way at Sears or Napa. Any idea what the timing should be set at?

[Wynkerdink]

Yes, this is my first Pontiac. I have a introduction thread waiting for mod approval with a few pics of the car. So far it's been a blast! It's just frustrating knowing it's not running right.

[performerrpm]

its possible that you have a timing cover from a later pontiac that had a bolt on timing tab for use with a crank hub, if this is the case there is a new timing cover to work with your fullsize balancer. pictures will tell for sure what cover you have

[Wynkerdink]

Here are the pics of the numbers

[Wynkerdink]

The rest of the pics. On the timing cover you can see where he marked TDC with a black marker.

I checked around for a timing light. I'm thinking about picking up this one from Amazon. The only bad part is it's 5-9 days for delivery.

[ITSBACK]

Thats a 67 motor and heads with original chrome covers. Is that the numbers matching motor? If so thats a good thing.

[Wynkerdink]

Originally Posted by ITSBACK

Thats a 67 motor and heads with original chrome covers. Is that the numbers matching motor? If so that's a good thing.

I believe it is, but after all the weird things going on with this car I can't say 100% if it is or not. The numbers all seem to match up to a 67 after looking them up on line.

I was able to get a hold of the previous owner and he was running a dual 4 barrel setup with electronic ignition on it. Until he burned it up by jump starting. Then he put the old stuff back on it. When I got the car it had the MSD ignition box bolted in, but not hooked up to anything, the resistor was bypassed sending 12 volts to the points and a vacuum line was just laying there not hooked up. It ran, but I'm not sure how.

[A.W.Dille]

Well from the looks of it the timing tab has been ground off so setting the correct timing is going to be very difficult if not impossible to set. Having a points ignition is old school but not as much a drawback as they may seem. Even though it has been years since I ran and raced with points ignition a good set of points like Accel or Mallory with a 32 ounce spring and a good are a must for high rpm using. Another thing is make sure that your coil is in good condition or upgrade to a better coil such as a MSD Blaster 2. If your using a resistor make sure the wiring is in good shape and it's mounted securely. There is nothing wrong with using a Quadrajet carb, just make sure you tune it properly. Also make sure the number 5 and number 7 plug wires are not touching and try to get the number 7 plug wire off ot the steering shaft as it will wear through the insulation and cause it to fire onto the steering shaft and cause the plug to misfire.

[A.W.Dille]

Sorry in the post about the points somehow the part about making sure your condenser is in good condition somehow got deleted. Also with the small cap on a points ignition spark scatter inside the cap is common, but can be reduced with a good aftermarket cap like an Accel or MSD.

[67 Lamnas]

Your heads are 1967 '670' heads, carb is a service replacement 1969 RA carb. Timing cover is a late '70s cover that requires the bolt on tab for timing reference, either get the tab or replace the cover with the cast marks in it.....nearly impossible to get an accurate timing setting without the reference unless you're good at 'setting it by ear'

Might want to monitor your engine temps with that undersize crank pulley......consider going to a larger (8") one for running cooler in the summer, especially if you are able to set your timing optimally and making more power.....the early (64-67) cars do not have as efficient a cooling system as the later cars.

The steady state 'hiccup' might be a lean condition, vacuum leak or less than optimal timing setting, the 'cutting out' is likely a fuel starvation issue.

Start with the simple stuff and have fun.....

[lust4speed]

Looks like the water pump pulley is smaller also, so his ratio might not be that terrible. No use doing anything with the timing light at this time since you have nothing to reference it to. It would be cheaper and a lot less trouble to find a bolt on timing tab. Even with a replacement timing cover, it still is a good idea to verify TDC, so why not save the money and get the tab - and then verify top dead center and bolt the tab down in its correct location.

So few of us run stock timing, and I don't see a great benefit in knowing the true timing advance. The mechanic should have done several test drives to see what timing the engine was happy with, and the trial-and-error method will give much better results than setting it by the book. Another reason to not set it by the book is today's lousy gasoline along with the combination of stock heads and pistons might require less advance. This engine will tell you where the distributor should be set. A good mechanic only starts with the timing light settings and then goes on to fine tune the engine for best drivability. You are close enough to proper timing to skip part one with the timing light, and just move on to finding the best distributor setting.

I agree with others that your Quadrajet needs to be set up properly. It's a good looking carb and appears stock as long as you don't get close enough to read the numbers. I wouldn't change it, I'd just find someone cabable of going through it and curing the minor problems.

[Cliff R]

If you installed an over the counter "kit" in the carburetor, it will NOT contain the correct high flow needle/seat assembly. This would account for the engine laying down at the shift point, and taking a second or two to recover.

The steady "miss" at light cruise is probably too much timing from the vacuum advance unit, and could also be a tad lean as Socrates mentioned.

The SR Ram Air carburetor is a nice unit, but we've seen them show up with several different calibrations, depending on the year they were produced. For todays fuel(s), it should have 73 if not 74 main jets, metering rods around 30-32 numbers smaller accordingly.

I'd also upgrade the accellerator pump assembly, those old style pumps don't cut it with todays fuel(s)......Cliff

[Ollie]

The first photo is a stock plastic bolt on timing tab.


Pontiac Dude,

A contributor to the forums sells a nice metal, bolt on timing tab. (Not shown)

Ram Air Restorations sells the one pictured below. This one requires removal of the front cover.

[Wynkerdink]

I'll try to get a hold of Pontiac Dude and pick up the timing tab.

The carb kit that went in was an over the counter one. It just had the gaskets and that stuff in it. I was over the shoulder as my friend (Dave) was cleaning and putting it back together. I do remember the main jets being 69, but I'm not sure about the metering rods.

I do have a temp gauge in the car and went for about a 45 minute cruise down the freeway at ~70. In the afternoon it was probably close to 85 degrees out and the temp was holding pretty steady just above 200. It never broke 210. When it's cooler and I'm going 60 it'll stay below 200. It has the 11 bolt water pump on it, so I think everything should be fine in that department.

Wow, there's so much information here. I'm definitely in the right place. Before I get overwhelmed, I'm going to start by concentrating on the miss. Hopefully the rain will stop today and I'll try plugging the vacuum advance and taking it for a spin. One thing I did notice is that the vacuum advance seems to be awfully far clockwise. The vacuum line running off of it rubs on the intake. It doesn't seem to be kinked though. It's as if the distributor was dropped in 1 tooth off. Would it be worth a shot to pull it out and try to move it back a tooth?

[A.W.Dille]

If the previous owner had a full twelve volts running to the points then it is a good possibility that the points are fried, and may have damaged the condenser also. Also if the previous owner had two fours mounted you may want to get ahold of him again and get the specs on the cam Also check the dwell angle on the points, should be right at 30 degrees.

[Wynkerdink]

The points were replaced by the mechanic when he discovered the 12 volts problem. He may have replaced the condenser also, I'd have to check on that though. When I talked with the previous owner I asked about the cam, but he pretty much had no idea what it was. I also asked him if he had any documentation for anything, but that was a dead end too.

[A.W.Dille]

If you can get access to a vacuum gauge then get a vacuum reading. Also is the vacuum advance hooked to full port vacuum (in other words to where it's pulling vacuum all the time) or is it hooked to a vacuum port to where it's pulling vacuum only when the throttle blades are opened? This can aid in helping to help you tune and hopefully help you locate the miss.