[TransAmRAFormula]

My dad and I have a 1972 Firebird Formula 400 and it is currently running terrible. We have had it for just over 9 years and have done quite a lot of work to it in that time and it seems like it is running worse and worse so I really need some help. I am at the point where I am starting to doubt that my mechanic really knows what's going on, so if anybody knows of a good Pontiac guy in northern New Jersey that would help too... So I suppose I'll take it from the top.

9 years ago we bought the car and it had the original motor, I am not sure if it was rebuilt or not. The only modifications were an Edelbrock carburetor, flex fan, braided spark plug wires, and Mickey Thompson valve covers.... One of the first things that we did is we had the original Q-Jet rebuilt by a reputable carb shop and we got a ram air air cleaner from Classic Industries with the rubber boots underneath the hood. I wish that I was driving the car back then so that I could tell how it ran, I didn't start driving the car until two years later and my dad does not remember if this made a difference to the car's driveability or not. We also replaced the valve covers with stock style chrome covers, though I doubt that would make a difference.

The next year we sent the stock log-type exhaust manifolds to Jet-Hot to get their ceramic coating and we reinstalled them with a stock exhaust system and transverse muffler, replacing the cherry bomb mufflers and side exit exhaust. We also replaced the plug wires with stock style spark plug wires from Classic Industries and we replaced the spark plugs with AC delco plugs and gapped them as per the specifications in our 1972 manual. We also installed a reproduction choke on the carb, and bought a new battery. Again, I wasn't driving the car yet so I don't recall any differences.

We changed the oil every year with Valvoline 10W 30 conventional oil.

The next two years I drove the car, and I regretfully admit that I beat on it hard. I was young and foolish, and I know better now. What's done is done.

About five years ago my dad thought that we were having vapor lock issues. I installed a new mechanical fuel pump and a new fuel line from the pump to the carb. I wrapped the fuel line with heat tape. A couple weeks later our alternator went, so I replaced it with a reproduction one from Classic Industries. I changed the oil again. The car seemed to run better.

Four years ago I changed the oil, the rear end fluid (I used gear oil and a posi-additive), and the trans oil (I used Red Line MTL oil). I also flushed the radiator and added new coolant and water with Red Line water wetter and the temperature guage would stay on 180 degrees all day. I also installed a K&N air filter into the ram air pan. I remember some hesitation with the car. If I was in first gear and stomped on it I would get a ton of lag. I also remember that the choke flap would get stuck open while driving which would have the throttle stick open. Also, if it makes any difference, A bolt snapped on the z-bar coming home one night making my clutch pedal useless. I just had to replace the one bolt which had a large ball on the end and fits into one side of the z-bar, but I ended up buying an NOS z-bar and new reproduction linkage parts and I replaced everything. I did not want another $5 part to cost me a $300 tow bill again.

Three years ago was when the major changes were made. The car was still running poorly and it was still hesitating, so I had the carburetor rebuilt. That didn't solve the problem. Then I installed a Mallory HEI distributor and coil and that seemed to almost make the car run worse.

Two years ago I changed the oil and then took it out to get a fresh tank of gas after sitting all winter and on my way home from the gas station the car coughed a cloud of black smoke and turned off on the middle of the highway. Another tow bill. I ended up letting the car sit all summer, then one day in October my dad decided to turn the key to see what would happen and it started up and seemed to run fine. I took it to our new mechanic because he got my friend's '67 Chevelle running fantastic. He tweaked the timing, which he said was out of whack and it was running great. Though, there was still a bit of hesitation. Not as much as before, but it was still present. My mechanic made no mention of installing a resistor to the coil to prevent 12 volts from going to the distributor.

Last year I changed the oil again. The car was having trouble starting, but it seemed to run okay. It still had some hesitation though. My mechanic said the battery was old so we replaced it. That was pretty much it, we did cosmetic work and a new braking system but that doesn't affect the motor of course. During the summer it would start fine and drive fine, still with a little hesitation in first though, but after just a short trip the car wouldn't want to start. Then in the fall the car would start like junk, but after letting it warm up it would run great with almost no hesitation. We put it away with fuel stabilizer like we do every year and we hooked up the battery tender.

That brings us to this spring. I did not change the oil yet this year. I am thinking about using Brad Penn oil because I read that it has all of the good oil additives that our oil needs. I replaced the flex fan with the original fan and clutch that I got with the car. I also was going to add an electric fuel pump but a lot of people including my mechanic told me that it wasn't necessary. I replaced the fuel tank and had the fuel lines checked. I also asked my mechanic if he could check out the motor for me and get it running well. When my dad picked the car up on Friday he said it ran even worse than when we brought the car to the mechanic and he had to sit on the side of the road and let it cool down. I called up my mechanic today and he said that was need a resistor for the coil, he said that we should get an aluminum radiator, and he said that we need a new fuel pump. He said that 4 years is a long time for a fuel pump on a car that doesn't get driven much...

Does anyone have a clue what could be going on? I really just want to drive and enjoy the car. It shifts fine, it has brand new brakes, brand new wheels and tires, and it is running terrible. I feel like I am running in circles. Any help would be greatly appreciated.

[bird72]

I throw questions like this to the Pontiac Street section for broader responses. Run quickly from your mechanic. He is suggesting fuel / electrical / and cooling solutions all in one day without seeing car. Your problem might be electrical or fuel and needs properly diagnosed. See if any local car people can reference a trusty mechanic.

[MescaBug]

You guys are running in circles, replacing every possible accessories around the engine, without adressing the engine itself.

Do you have any idea what's going on in the engine itself? The core is the engine, not what's around it.

- What's the compression on each cylinder? Did you guys, or your mechanic, do a cylinder leakdown test? If you're low on compression on all cylinders because the piston rings are shot to hell, you'll never get that engine to run.

- What's the vacuum reading?

- What's the condition of the timing chain? If its slopping around with enough slack to make a knot, you'll never get anywhere.

- Maybe the cam has flat lobes on all valves?

- Maybe the valvetrain is not adjusted properly, or loose pushrods, collapsed lifters, stuck valves...

I strongly suggest you stop loosing time, take that poor engine out of there and rebuild. You will never stop going in circles if you dont assess the condition of the engine. Having an engine cleaned and rebuilt to stock specs doesnt cost and arm and a leg. Save your time, its worth it.

I do understand that's not of much help, but that's probably the best suggestion you will get here. We cant help you if you dont know anything about the internals of that engine.

Good luck and keep us posted!!

[Mezzo]

If you are running the original QJet, check the power piston spring. It may have the wrong tension thus creating a lean condition. Does it back fire?

[superdutybob]

Originally Posted by MescaBug

You guys are running in circles, replacing every possible accessories around the engine, without adressing the engine itself.

Do you have any idea what's going on in the engine itself? The core is the engine, not what's around it.

- What's the compression on each cylinder? Did you guys, or your mechanic, do a cylinder leakdown test? If you're low on compression on all cylinders because the piston rings are shot to hell, you'll never get that engine to run.

- What's the vacuum reading?

- What's the condition of the timing chain? If its slopping around with enough slack to make a knot, you'll never get anywhere.

- Maybe the cam has flat lobes on all valves?

- Maybe the valvetrain is not adjusted properly, or loose pushrods, collapsed lifters, stuck valves...

I strongly suggest you stop loosing time, take that poor engine out of there and rebuild. You will never stop going in circles if you dont assess the condition of the engine. Having an engine cleaned and rebuilt to stock specs doesnt cost and arm and a leg. Save your time, its worth it.

I do understand that's not of much help, but that's probably the best suggestion you will get here. We cant help you if you dont know anything about the internals of that engine.

Good luck and keep us posted!!

I agree with Mesca that understanding the condition of the base engine is the most important. You may not have to rebuild the engine but at least find out what's going on. Throwing unknown parts at an engine never ends well.

[rohrt]

I don't think you need to yank the motor just yet but it would be good to take a systematic approach to the issue.

I agree with MescaBug
get a vacuum reading and a timing reading at the very least. A compression and leak down test would be good to. Also what do your plugs look like?

You mention the hesitation several times. Can you describe it a bit more. I assume you mean the car bogs on acceleration? This has me thinking the accelerator pump in the carb may have a rip or went bad. Could be a stuck advance in the distributor too.

[Region Warrior]

Basics first.
If unable to do a compression and/or leak down test, check timing and for vacuum leaks.
What do the spark plugs look like?
Another common problem on old Q-jets(even rebuilt) are well plugs leaking fuel. Also sloppy throttle shafts.

[Formulabruce]

Now running alcohol gas which require a a different tune and runs hotter

[Sirrotica]

Agree that you need a compression check, vacuum readings to at least start in the correct direction. A leak down test would pinpoint the weak areas if there are any. Cam lifters and bad valve sealing along with ring seal.

Your car most likely had a point distributor in it and the ignition wire is resisted down to approx 7 volts so the points don't fry. If you hooked the resisted wire up an HEI style distributor, they require 12 volts and will barely if at all run on 7 volts. Very possibly why it ran worse with the HEI in place and will definitely cause hard starting especially when cold.

Running conventional oil very likely has cam lobes and lifters going away, dumping Brad Penn in at this point is like closing the barn door after the horses ran away, it won't change anything.

Beating on the car like a drum early on certainly didn't have any good effects on your engine and very possibly started the demise of internal engine parts. The aforementioned tests will tell the tale if the engine is in need of an overhaul, or maybe a cam and set of lifters, timing chain and gears could be changed, if the rest of the engine is still sound. Your right that you are in need of a mechanic familiar with Pontiacs as well as engines and the basics of engine testing of the era of your car.

Go get some readings from the aforementioned tests and post them here for a better forecast of what direction you need to go in. Without results from these tests it's just guessing.

[TransAmRAFormula]

Thanks for the replies everybody. I have a Mallory Unilite distributor, which apparently is not quite an HEI, so I apologize for the miscommunication. In the directions it states that a ballast resistor is required if the original wire loom is not being used. I did have the original points distributor installed, so I assume that the original loom was in place. But my mechanic read 12 volts so I ordered a ballast and will be installing it today.

We have had the car for over 9 years now and have never seen the inside of the motor. I have asked my mechanic to do a leak down test and compression test several times now and I cannot figure out why he won't just do the tests for piece of mind. I also remember the timing chain being a bit loose when I replaced the fuel pump a few years ago.

I will be taking the car to him this week and I will have him check the motor for me. It's very strange, he does a lot of muscle cars and he worked wonders on my friend's '67 Chevelle, I don't know why he's having such a tough time figuring this out.

I really hope that I do not have to rebuild the motor. I already have a $14,000 455 sitting in my garage that I built 2 years ago and I have nothing to put it in. It was originally going in a 1972 Firebird shell that I have, and it looks like it needs about $30,000 in metal work and body work + paint, so that won't be ready any time soon. I'd install it into the '72 Formula in question but I am afraid that the rest of the car won't handle it. The suspension and everything looks like it's all original. I don't know how the trans or rear would hold up, all of the bushings are dry rotted, the frame has a bit of surface rust... The car needs a bit of TLC to be honest. We did a complete brake overhaul last year and replaced the shocks and leaf springs as well as the gas tank. I have all new bushings that I was going to install next year.

I'll talk to my mechanic on Monday and tell him what I want to do. If anybody knows a good Pontiac guy in North Jersey I am open to switching mechanics, I want to get this figured out and I'm losing my patience with this current guy. I feel like I am going in circles and I want to drive the car and enjoy it but I can't drive it more than 15 minutes without worrying if I'll need a tow truck or not. My mechanic seems to have the outlook that it's an old car and old cars sometimes break down. I realize this, but I don't think that it's unreasonable for me to be able to go on a couple hour trip with my car without something happening.

[TransAmRAFormula]

In addition, the other day my dad picked up the car from the mechanic and got about 3 miles away before he had an issue... The mechanic drove over to him and the water in the radiator was boiling over, yet the temp gauge never goes above 180... The radiator has some corrosion in it and I am going to have it redone into a 4 core. Could that be the issue?

[Sirrotica]

Read this thread about cooling system issues in Pontiacs, almost any cooling system issue is addressed here. It will probably take you a few hours to read through it, but there is a wealth of information about Pontiac specific cooling system problems.

http://forums.maxperformanceinc.com/...ighlight=chalk

Maybe your "mechanic" should read it too....................

Although Pontiacs and chevys share some characteristics and problems in common, they have many more that do not require the same fixes. The main reason a chevy person tries the same things that work on chevys and they do not work on Pontiacs.

[rexs73gto]

I have to say if you have asked your guy to run the tests we've said to & he hasn't done it I would not take ANYTHING back to him. It doesn't sound like he knows anything about Pontiacs. If you tell your guy to do something & he doesn't, he's just there to take your money. Don't take it back to him unless you have a big wallet . If he hasn't figured out your problem by this time he never will. Your just wasting money now. A good tech should be able to fix your car when he looks at it & even a half ass tech will be able to run the tests to figure it out. If not dump the tech because he doesn't have a clue.

[74 SD455 Formula]

I had a similar problem of over heating and running like crap with my 72 455 HO GTO. I changed the Thermastat from a 185 to a 160 and put in a 4 row Desert cooler Raditor. Now I can run the car all day any where in 95 degree weather with the A/C on without any problem's.You also have to watch what gas you are using. And for what it's worth my motor and carb were last rebuilt in 1998.It is now a 467ci Butler Performance motor.

[Pepi]

I am trying to remember if someone else was complaining about their car running like crap and same thing, they were taking it to a mechanic that did a lot of work on chevy's. I thought it ended up being spark plug wires being crossed or a couple being wrong because different rotation. Just a thought quickly check and make sure all the plug wires are correct. Easy enough for you to do yourself. 1-8-4-3-6-5-7-2 counterclockwise rotation.