69 340 problems

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George R

George R

Mopar Nutcase
Joined
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Location
Trumbull, CT
I thought my fuel pump was bad because the car died while running, and when I checked the carb squirters, there wasn't any gas coming out. Tonight I removed the fuel pump, and tested it with mineral spirits by hand. Seems to work perfectly. When I had the rubber fuel line disconnected from the pump, the fuel wasn't running out from the main line like I thought it should. In fact, with the hose hanging next to the K frame, no fuel was coming out of it. I blew air into the line to be sure it was clear, and I can hear the bubbles in the tank. I then pulled a vacuum on the line from the fuel pump end, and got fuel to come out EASILY. I reinstalled the pump, and the car started, but ran VERY poorly, has NO throttle response, and shortly died again. I played with the timing in an attempt to get it to start, but it didn't make any difference. Finally, on the last attempt to start the engine, I got no response from cranking. The engine turns over quickly, but will not start. When it did start, it barey ran.
I have no idea where to look, and my love for this car is quickly diminishing. I need sound advice, or a visit from a knowledgable Mopar guy.

Do you guys have any pointers you can throw at me?

George
 
How many miles are on the engine? Are the ignition parts new? Have you noticed a smell like the engine is running rich? Need a little more information to take a stab at this.
 
George is this a new tank ? Clogged sending unit sock maybe ? Maybe open up the carb and take a look for junk inside.
 
The engine has 90,ooo miles on it, and doesn't blow any blue smoke. All tune up parts are new. When it ran (and it ran quite well until last Sunday) it didn't smell rich, had decent throttle response, and a steady idle.

The fuel sending unit is original, and looked clean when I looked at it through the filler neck opening.

The tank is also original, and was clean as a whip inside. I opened up the carb tonight, and the fuel level was even with the top of the thin metal "slosh" plates inside. It seems the accelerator pump doesn't push fuel through the squirters until it is way down in it's bore. Is this normal? Its the original AVS, recently rebuilt. The inside of the carb is spotless.

The gas in the tank is new, it is 1/2 full, and the fuel filter is new.

This engine wasn't rebuilt, but all the accessories connected to it are new, rebuilt, and were good original parts.

I wonder if the 318 distributor that is in the car has a problem. It seemed tight when I had it apart, and I put new advance springs and vacuum advance can on it. I have no idea where the timing is set, however. I haven't put a light on it.
The car would start with a click of the key prior to the time trouble started last Sunday.

Thanks for all the responses.

George
 
what kind of fuel pump? the holley on my car went bad with only a few miles on it.

I put a clear glass filter between pump & carb and a cheap fuel pressure gauge to determine the pump was bad

good luck
 
It has a generic parts store fuel pump on it, and since installation it has 3 or 4 miles on it, and maybe 30 minutes of run time in my driveway. I suspected the pump when I saw only a little fuel coming out of the accel pump squirters, but now I see that the accel pump only puts out fuel from about 1/2 pedal onward. Is this normal? I know it isn't right on a Quadrajet or a Holley, but this is an AVS and I have no knowledge about them. On the same note, the level of fuel in the bowls (with the carb top removed) is about level with the thin metal slosh plated in the carb. Does this sound right? When the top of the carb is held upside down, the floats themselves are level with the top of the carb. In other words, the float and carb top are parallel when held in an inverted position. Does the float level sound about right?

When it sputtered to life last night, it ran as if the timing was very retarded. I advanced the timing with the distributor until it was hard to crank over, and it did start, but only for a second before sputtering and shutting down.

The timing chain is original, and when I had the front cover off, there was only a little play in the chain. How would a guy know if the chain jumped a tooth? It is the original double row roller chain.

I dunno what to do next.
Thanks, guys, for the help.

George
 
At 90000 miles you are way overdue for a timing chain. Pull the front cover and rotate the engine to TDC with a socket and breaker bar. Rotate the engine backwards from TDC and see how much slop appears. I'm betting around a quarter turn to take up the slop. That's how it was on all the ones I had that mysteriously quit running, and they do it with no warning. Hope I'm wrong. If this is the problem, don't forget to check for bent pushrods and valves. My best tally was 16 pushrods and 12 valves. IMO the Mopar Performance timing chain tensioner is a good investment.
 
A '69 340 has a double roller timing chain with steel sprockets on both cam and crank. I doubt that is the problem.
 
Sometimes we chase a fuel problem on an engine that could have an electrical problem.

My orange box was new. Ran good for a short while. Then started having problems as you described. Took the carb apart, (AFB at the time), replaced fuel pump, checked timing. Would not idle. Replaced orange box...problem solved.

You could still get a bad new electrical component.

The accelorator pump has nothing to do with the idle circuit on you AVS, although I never had any luck with those pumps.

I would bring No. 1 to TDC and see where your timing marks are. If its way off, (bad balancer or jumped tooth), resolve that first. Try to get you timing about 10* advanced for now.

If you have good flow from the fuel pump, it could be electrical or a plugged idle circuit in your carb.
 
340sFastback said:
A '69 340 has a double roller timing chain with steel sprockets on both cam and crank. I doubt that is the problem.
Click to expand...

When I bought my '77 Roadrunner (318) there were 2 things I did to it when I got it home from the dealership. I took the catalytic converter off so dad could take it to the plant and run a 2 1/2" drill through it and weld a piece of 2 1/4" ID pipe inside it. While I waited for dad to get back from the plant with the converter, I changed the timing chain and sprockets over to Direct Connection double roller. The car had 17 miles on it. The chain lasted 75000 miles. Granted, that's a lot better than the 50K you can expect from a link plate stocker.
 
I would check the valve timing George and make sure that everything is where it should be first and then move to fuel and ignition.
 
Thanks to NiceFish for jogging this nugget loose, and I really hate to get off it for nothing. To find out if your chain is shot without a teardown you will need a breaker bar and a 1 1/4" socket for the crank nut. Pull the distributor cap and turn the engine over by hand while watching the rotor in the distributor. Turn the engine about 2 revs and then rock it back and forth about 3 or 4 times. You can feel the slack while you are turning the engine back and forth if the chain is really bad. To make sure, watch the rotor and if it does not turn in step with the crank the chain is bad.
 
Could be bad gas or water in the gas (among all the other things it could be).
Try running it with a gas can with clean fresh fuel.
Everything you've described about the carb floats etc.. seem perfect except for delayed acc. pump squirt which can cause hesitation. Thats adjustable.
Only similar problem I recall was venturi bleed tube had fell out of where it is staked in the casting. Was a 2 barrel on a 318 but same condition. Engine would only try to run , poorly and briefly.
 
It sounds to me like maybe the carb's not set quite right, but the problem sounds more ignition related. WIth starting and pumping and whatnot you may have wet fouled plugs now, or just got out of whack on teh distributor. I would suggest takign a break if you can, pull the plugs and hitt hem with brake cleaner and a wire brush, and then looking into the dist again. I'm in CT, but it's like 1 1/2 hours one way to Trumbull.. I'm on the worng side...lol
 
Well, I replaced the fuel pump with a Carter model, and there is no change; engine does the same thing. I removed the inline fuel filter and replaced it with a rubber hose. No change. I set the balancer to #1 TDC, then checked the rotor tip to be at #1 on the cap. It was.
I tried to start the car, and it "runs" like the timing is WAY retarded. It barely stumbles to life, then simply shuts down.
There is still BARELY any fuel coming out of the squirters, even after the short run time so I suspect carb needle/seat problems. I poured some fuel into the carb, and although it ran, it still sounds like the timing is very retarded.
I will use Grump's method to check the timing chain, and report back. Maybe the chain is now off a tooth, and there are also carb problems? It just seems strange that it happened "all of a sudden".
I am starting to dislike this car. :D

THANK YOU all for the help.

P.S. If it was a stock Chevy with 90,000 miles on it, I would say it needs a timing chain after listening to it "run", but because it has a double row roller, I was ruling it out. Like I said, I saw and felt the play in the chain when I had the timing cover off this spring, and it didn't seem that bad.......to this Mopar newbie.
I'll report back when I know more.

George
 
Well, I did as Grumpscreature said, and turned the motor by hand while looking at the rotor. There is 15º of crank rotation before the rotor starts to turn, as marked on the balancer. Is this too much timing chain play? If so, would it make the car run as if the ignition timing was severly retarded?
Thanks for all the help guys.

George
 
small block Mopars are notorious for play in the timing chain. It wouldnt be a bad idea to change it and add a chain tensioner. Mancini Racing sells them for around $40
 
If it did jump a tooth it will be retarded. I use to verify this by advancing the distributor on a suspect chain jump and usually would cause the motor to be able to start. The squirter not spraying is probably a bad accellerator pump which is common to go bad on the afb's and avs with age
 
Have You Disconnected The Fuel Line To The Carb,,put It In A Jar,,crank The Motor,,see How Much Fuel Pumps Out Of The Fuel Pump ??? Worn Out Excentric ??and Timing Chain
 
No, I did not do a fuel volume test, BUT, when I removed the inline fuel filter, there was pressure in the line. Maybe the needle/seats are (once again) sticking closed blocking fuel from entering the bowl. I'll look into it further.

In the service manual, it recommends timing chain replacement if there is 3/16" of play at midpoint between the cam and crank gears. When I had it apart before I installed the engine, I remember the play being closer to 1/2". I'll tear into it this weekend and order a timing chain.
Will a NAPA roller replacement chain be good, or should I go to the Dodge dealer for it?

George
 
Thanks Bill. I have purchased Cloyes chains in the past. Good product.

I took the front of the motor apart this am, and the timing chain looks EXACTLY like it did when I had the front cover off this spring. There is about 1/2" of play at midpoint, but there is NO WAY it could have jumped a tooth.
I see the dot on the cam sprocket, but there are some (what appears to be) letters on the crank gear that could indicate TDC. I hope I am reading it correctly, but they still line up with each other.

I will replace the chain because it is apart, but I seriously doubt this is the trouble.

Is there supposed to be an oil slinger on the crank or cam somewhere? I don't see it anywhere.

George

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