# What's the solution to my symptoms?



## Comicazy (Feb 24, 2010)

I've hit a wall trying to keep my 1970 Tempest running in gear. I used a vacuum gauge to tune the timing and Air/Fuel mixture to it's optimal running vacuum. But ran into two seperate, yet linked problems. 
1. If I set the timing with the distributor to get the best steady vacuum, the car will stay running in gear. But, it fights itself when I try to start it. I was told, that it was because the timing was too far advanced. Sounds right to me.
2. If I retard the timing so that the engine will turn over easily, the car will not stay running in gear no matter how high I set the idle screw. Also with it retarded, after running for about 30-60 seconds, it will start to sputter and I have to feather the throttle to keep it going.
So I'm leaning towards a couple of possibilities.
1.Distributor weights and/or vacuum advance is jacked up. - Solution:New distributor from Summit.
2.Torque converter does not have high enough stall causing too much load for the engine to keep runing - Solution:replace with higher stall converter(2200)?
3.Engine has been rebuilt and has a higher compression than the starter is able to turn - Solution:High torque Starter.
Let me know what you think and any question or ideas that may lead me closer to finding the solution. Thanks.

Comic


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## Too Many Projects (Nov 15, 2008)

What is the timing at when the car will run but not turn over to start ? 

It is possible for the mechanical advance to seize up from non-use but a simple look under the cap to see if the rotor will turn the advance movement will tell that story.

Do you KNOW that the engine has a high compression rebuild or just a guess with the other symptoms ? If it is a race engine, yes the torque converter could need replacing and a high torque starter would help BUT they will be money wasted if they aren't absolutely necessary.

Now, when you are adjusting the carb, can you turn either mixture screw in without any noticeable change ? If only one screw is feeding the idle, you may need a carb overhaul to clean out the idle circuits. It is very common for them to run on only half the carb resulting in only half the cylinders getting fuel at idle but still run OK on the road with fuel feeding thru the other circuits.


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## Comicazy (Feb 24, 2010)

I would have to get a timing light to be sure what it is set at.
I don't know if the engine has high compression or not. That is just an educated guess because I had the same problem with the 383 my Dad and I had built for my Nova. The torque converter was putting too much of a load on the engine at such a low RPM that it caused the spark plugs to load up and foul. The Tempest shows many of the same symptoms, including wanting to lurch the car forward when I have the brakes applied as much as I can. I almost have to stand on the brake pedal to keep that car from moving. 
I have used two different carbs and get the same results. An old Holley carb came on the car when I bought it. I replaced that with a 650cfm Edelbrock then went back to the holley with no change. On both carbs, turning either mixture screw all the way in will cause the engine to stall.
Also on a side note, it seems the car is incapable of doing a brake stand. I can break the tires loose going around a corner and the tires slip when going into second gear on a hard acceleration. The rear end gears are 3.73 that I had installed a couple weeks back. Thanks.

Comic


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## jetstang (Nov 5, 2008)

What size engine is in the car, what tranny?
My 454 hard cranked when warm, I put a gear reduction starter and it never hardcranked again. Replace the starter, check your grounds, engine to frame, frame to battery, weak ground will make a starter slow crank.
New distributor would be a good call, I got mine off ebay for $60, works great, but hearing about failures, I have 3 and they work great.
Something is def off, keep working, sounds like a vacuum leak if it doesn't want to idle. Make sure all the unused vacuum ports are blocked off.
You need a timing light to set the engine, if you have a weak starter and keep backing it off until it cranks easy you may be retarded, lol..


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## Comicazy (Feb 24, 2010)

As far as I know the engine and trans are both 350. That's what I was told when I bought it. Have not positively ID'd them yet but I am pretty sure. It hard cranks whether it is cold or warm. Just as long as the timing is set that way. 
So for now since I HAVE to drive it to work, I leave the Dist a little loose so i can retard to start and advance to keep it running. Not a permanent solution, but one that works for the moment until I can get my Firebird out of the garage and get this in there and tear it apart.
I have to return a tool that I didn't need or use, so I might get a timing light with the money I get back. I know I need it. Thanks.

Comic


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## jetstang (Nov 5, 2008)

Unless you have an HO 350, compression shouldn't be an issue. Same starter goes from 326 to 455, so I don't think your engine should give the starter a challenge. Bad starter, grounds, and tune. Get it all right and you should be happy. I tune by ear, time to the max, and back off til it doesn't ping. An 1/8" is alot when timing, so don't just jerk the timing around. Make marks on the base of the distributor for reference and tune from there.
Does it idle lopey or smooth? Or sound like it's missing?


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## 66tempestGT (Nov 28, 2009)

did you have the same lurching problem before you installed the 3.73 gears. i assume the old gear was a higher ratio.


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## Comicazy (Feb 24, 2010)

jetstang-I think it idles smooth most of the time, but seems to shudder every once in a while. While watching a vacuum gauge, it holds steady around 15 and drops to 14.5 or 14 every once in a while. At first I thought it was backfiring, but I think it was a miss caused by a spark plug that had been hit against something and the gap was 0. SO I reset that and checked all the other plugs and the miss went away. But the vacuum still drops every once in a while. Could excessive back pressure be the cause of some of this? The exhaust on my car is no bigger that 2.25. Maybe 2.5 but I doubt it. Is there any way to know if it is a HO 350? Or possibly a 400? What exactly does a ping sound like? 

66tempestGT- I don't think it used to lurch as much, but it did used to stall in gear the same way. The old gears were non-posi 2.78 or something close to that. Now it's posi 3.73.

Thanks again.

Comic


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## jetstang (Nov 5, 2008)

The engine ID number is stamped on the left front of the block, next to the cam cover. Also, on the back under the distributor is embossed the engine size and year of engine. 15 pounds of vacuum is low for a stock engine, stock can pull 19-20 pounds of vacuum. Assuming it stock, it should run dead smooth without any stumbles or lurching. Is it points or HEI? I would convert to HEI if you can.


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## Rukee (Feb 8, 2007)

the pinging kinda sounds like someone shaking a ring of keys under the hood when your on the throttle hard.
Were is your vacuum advance hose connected?? To manifold vacuum or ported vacuum??


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## Eric Animal (Oct 28, 2007)

Possible fuel supply issue?


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## 66tempestGT (Nov 28, 2009)

when you make a big gear change like that it lowers the stall rpms of your torque converter. sounds like you have a bigger problem but the gear change has magnified the symptoms. when you get it straightened out you will probably want the higher stall converter you mentioned.


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## Rukee (Feb 8, 2007)

66tempestGT said:


> when you make a big gear change like that it lowers the stall rpms of your torque converter. sounds like you have a bigger problem but the gear change has magnified the symptoms. when you get it straightened out you will probably want the higher stall converter you mentioned.


I don't agree. When the car is stopped say at a stop sign and idling in gear, the motor/tranny doesn't care what gear ratio is in the rear end. It's stopped and idling no matter what gear ratio the rear end has. You pick your stall converter more by what cam and engine components you have, not the gear ratio of the rear end.


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## 66tempestGT (Nov 28, 2009)

im not a scientist so i cant explain it to you in minute detail, but it has to do with torque multiplication. it will change drastically with different gear ratios. if you take a car with a 2.73 and hold the brake and slowly raise the rpms you will get to a point where it tries to overcome the brakes. change the ratio to 3.73 and it will overcome the brakes at much lower rpms.


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## Too Many Projects (Nov 15, 2008)

66tempestGT said:


> im not a scientist so i cant explain it to you in minute detail, but it has to do with torque multiplication. it will change drastically with different gear ratios. if you take a car with a 2.73 and hold the brake and slowly raise the rpms you will get to a point where it tries to overcome the brakes. change the ratio to 3.73 and it will overcome the brakes at much lower rpms.


Shane, what you say is true but as Rukee says, at an IDLE it shouldn't matter. The key here seems to be that he has to have the timing and idle so high that the converter IS locking up and coming into the equation. I"m thinking he may have a massive vacuum leak causing this. He should be eliminating vacuum sources to determine that. I would start with the brake booster. If he has to push that hard, it may have a ruptured diaphragm and is not assisting besides causing the vacuum leak. If that is OK, I would then check the PCV valve, etc. Moving from the largest hoses to the smallest. The other possibility is that the timing chain/gear is worn and jumped. You can get the engine to run again by twisting the dizzy far enough but it doesn't run good...
And yeah, he absolutely needs a timing light to know where he's at and where to go from there.


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## Comicazy (Feb 24, 2010)

Wow, lots of replies. Thanks guys. I'll work from the top down and answer what I know for sure.

jetstang- I will check for the engine ID tomorrow. Do I have to pull the distributor at all to see the numbers back there? Or just wedge my head back there real good with a flashlight? The guy i bought it from said the engine had been rebuilt a while back and it had a mild cam. So could that be a possible reason for the low vacuum? I was planning on replacing the dist with an HEI from Summit. I was told that right now the points are gone and it has a pertronics electronic ignition in it. So it still has the coil wire plugged into the top.

Rukee- Ok, no rattling keys under my hood. The vacuum advance is hooked up to ported vacuum. And the trans is hooked up to manifold. If I were to suck on the advance hose real hard while it is idling, should the engine react in some way so I know it is working?

Eric Animal-I don't think it is a fuel supply issue. It never seems like it is starving under hard acceleration.

66tempestGT/Rukee-Yes it does try to overcome the brakes sooner, but even with the lower gears it had before, it would still stall out when it was put in gear. So I guess I would have to agree with Rukee about my current problem. Yes torque multiplication plays a factor, but only in relation to power transfer to the rear wheels. From the the drive shaft forward, everything is the same.

Too Many Projects- I think the issue with the torque converter locking up has to do with the fact that it locks up outside the power band of the engine. If I lower the idle RPM's the engine doesnt have the power to push past the lockup and try to move the car. If I raise the idle, it pushes through and tries to move the car. If the idle is set so it runs in gear, as soon as I release the brakes the car starts rolling at a good pace. Most cars you have to give a little gas to get the converter moving fast enough to transfer power to the trans. So it could also be that the torque converter is seized up causing it to be permanently locked up.I am pretty convinced that this car was once a swamp car. So that could be my entire problem. As for checking vacuum sources like you said, it doesnt have a brake booster, so no problem there, but the brakes shouldn't have a problem holding the car back at a stop light. PVC hose fits snug. Even has a hose clamp on it. All other vacuum ports are either used or capped off. And i've sprayed carb cleaner around all intake and carb gaskets without any change to the RPM's so no leaks around there. I sure hope the timing chain hasnt jumped.
Again, thanks for the responses guys. I'm sure with the collective knowledge you guys have, I can find a solution or solutions.

Comic


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## jetstang (Nov 5, 2008)

If it isn't missing, sounds like a huge vacuum leak as stated before. Spray starting fluid or WD-40 between the head and intake, and carb, and listen for RPM change. Could be you have 2 bad carbs, borrow a carb from a buddy and try it. Get a timing light!
Your torque converter is a non-lockup converter and can't lock down. Think of 2 fans, 1 is on and the other is spinning because the other is blowing on it, well, that's how a torque converter works with trans fluid. Less fan blades on receiving fan=higher stall.
I saw my Engine numbers with the engine pulled, but they are about an inch tall, spray some carb cleaner at the rear of the engine and brush around, you should be able to see them.


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## khinton (Jun 22, 2008)

Are idle screws on the carb adjusted correctley? Could be that simple. Off too much can cause low vacum readings.--I would though suspect a vacum leak.


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## Comicazy (Feb 24, 2010)

jetstang- As I said in post #16 I have sprayed all around the heads/intake and carb with no RPM change. I know the Edelbrock carb is not messed up because it is the same carb I used on my Nova and I ran that car across country with no problems in any state. Ok, so maybe the converter does not lockup, but it could still have such a low stall that it is causing too much load on the engine at a low RPM.

khinton- I adjusted both idle screws on both carbs to achieve MAXIMUM vacuum. Turning either screw in either direction causes the engine to react negatively and the vacuum drops or starts to waiver a great deal.

Comic


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## Too Many Projects (Nov 15, 2008)

OK, you said it has a Pertronix conversion in the dizzy with a stock coil. What are the plugs gapped at ? I recently installed an used engine in a car and couldn't get it to idle worth crap. It ran similar to yours.....poor idle and need to set idle up and feather throttle in gear to keep running. I even had an intermittent flash from the timing light and it was hard to time ! I was thinking I had a bad Pertronix but it had been in the engine I removed and worked flawlessly. I tore my hair out for 3 days until it dawned on me that the previous owner had an HEI dizzy and the plugs were gapped at .045. I closed them all down to .035 and it runs like a watch. I too have a Pertronix conversion with a stock coil and Edelbrock carb...


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## Comicazy (Feb 24, 2010)

That was what I thought too, so pulled all the plugs and checked them. Some were a little off and I set them to .35. But that didn't change anything noticable. And actually the coil is a pertronix also I'm pretty sure. I'm thinking I just need to get my firebird fixed and out of the garage so I can get the tempest in and start tearing it down. My weekend starts tomorrow, so maybe I will tinker with it while I wait for parts for my firebird. I'll try some of the suggestions people have made so far and see if anything helps. I'll post results when I see them. Thanks.

Comic


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## 66tempestGT (Nov 28, 2009)

i would take the nova to the track to clear my mind, then worry about it next week. :cheers


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## jetstang (Nov 5, 2008)

Comicazy said:


> jetstang- As I said in post #16 I have sprayed all around the heads/intake and carb with no RPM change. I know the Edelbrock carb is not messed up because it is the same carb I used on my Nova and I ran that car across country with no problems in any state. Ok, so maybe the converter does not lockup, but it could still have such a low stall that it is causing too much load on the engine at a low RPM.


I wasn't trying to be offensive, sorry.
Keep playing with it, may be something internal that is messing it up. I put a Brand new Holley 750 on my old 400 and it always had a stumble and a tick. Pulled it apart and had two dead cam lobes. If you've done a complete tune up and the tune is right, might be time for a compression check and see what condition the inside of the motor is in, also a cylinder leak check to check the heads and rings.
Back to the basics, set it so it runs good and buy a new starter that doesn't hot crank.


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## Comicazy (Feb 24, 2010)

66tempestGT- I wish i could take the Nova down the track. I am stationed in WA and the car is in my Dad's polebarn in MI. Ah how I miss that car. Only get to see it a couple times a year for now.

jetstang- It's not your fault. I was just getting home from a bad day at work that day. Add on the frustration of trying to get that engine running right, and I was just plain aggrevated. I have so many possibilites going through my mind of what could be causing this. I have to remember to slow down and try one thing at a time to find out what exactly fixes it. Like I said, I will t work with the suggestions given to me and post results so we can figure out what it is that is going wrong. Thanks again.

Comic


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## jetstang (Nov 5, 2008)

Comicazy said:


> jetstang- It's not your fault. I was just getting home from a bad day at work that day. Add on the frustration of trying to get that engine running right, and I was just plain aggrevated. I have so many possibilites going through my mind of what could be causing this. I have to remember to slow down and try one thing at a time to find out what exactly fixes it. Like I said, I will t work with the suggestions given to me and post results so we can figure out what it is that is going wrong. Thanks again.
> 
> Comic


I repair broken equipment for a living, and can't leave til it's fixed. I've found that you spend enough time with a piece you will figure out what is wrong with it. Yes, swapping parts from a good one to a bad one makes it easier to troubleshoot, ie. buddy's carb. I buy the cheapy ebay HEI distributors and haven't had an issue yet, brand new everything for $60. At least you know your advances are working and don't have to rebuild old units.


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## Comicazy (Feb 24, 2010)

Is this a good one?

PONTIAC TEMPEST HIGH OUTPUT HEI DISTRIBUTOR # 6504-R : eBay Motors (item 350332165132 end time May-12-10 16:00:00 PDT)

Comic


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## jetstang (Nov 5, 2008)

Comicazy said:


> Is this a good one?
> 
> PONTIAC TEMPEST HIGH OUTPUT HEI DISTRIBUTOR # 6504-R : eBay Motors (item 350332165132 end time May-12-10 16:00:00 PDT)
> 
> Comic


Yep, that's it. You can search on GTO or Pontiac and get more results. Looks like a good price.


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## Comicazy (Feb 24, 2010)

Found the Numbers behind my dizzy. 70 0830. Can anyone tell me what these mean besides that it's from a 70? Are there more of them back there?

Pulled off the intake to get at the carb nut I dropped down there. There is a little rubber grommet or something that goes in the hole for between the water pump and the intake. Anyone know what that is called so I can get a new one? Also, found a couple cracks in the intake. It's around the hole right in the middle on the drivers side. Looks like oil or something is supposed to go through there. What kind of problems can that cause? Vacuum problems?
The rotor in the dizzy moves back and forth, so it looks like the mechanical advance is working. 
Going to run to the parts store to get intake gaskets so I can put it back together. I know I'll have to get a new intake, but might as well keep it able to move under it's own power for now until I can get it in the garage.

Comic


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## jetstang (Nov 5, 2008)

The very center hole is the heat riser, any leaks there could be vacuum, but should be exhaust leaks. If you haven't put the intake back on, you can make some gaskets and block off the heat riser if you want. New intake gaskets may help the car and it may fix a lot of your problems. The front open port is for your PCV. Mine was as hard as a rock, I just got a generic PCV grommet for the valve cover and put it in, doesn't fit perfect, but works. Was your PCV in this hole or in the valve cover?
Don't know what the 0830 is, but the 70 means 70. Keep cleaning, the numbers are back there, and there big.


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## Comicazy (Feb 24, 2010)

My PCV is in my valve cover. This hole actually went to the water pump. It had fluid in it too. I will take a pic of it tomorrow and post it.


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## jetstang (Nov 5, 2008)

Oh, the front hole, that gasket should come with the new intake seal set. I would throw some rtv on the gasket just to seal it up a little better. Be careful with that long bolt, it's strips out real easy.
Odd your PCV is in the valve cover, most go in the valley pan right behind the thermostat. It won't suck as much oil in the valley pan as it can in the valve cover, especially if your valve cover isn't baffled.


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## Comicazy (Feb 24, 2010)

Ok, I think I know what you are talking about now. Yea I tried to take that bolt out and it just kept turning. Any advice on how to get it out? Or would I have to take off the entire valley pan?


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