Sick Motor...

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64X2

64X2

Mohel at your service.
Joined
Oct 13, 2008
Messages
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Location
kentucky
72 318 Block .30 over
79 318 Heads, not sure of the casting number think they are 72 cc chambers
1.88/1.60 valves
Purple cam 276/284 .444/.453" 112 degree
LD4B Edelbrock intake
650 Edelbrock carb
Windage tray
Double row timing chain
Mopar Electronic ignition with and orange ECU box


This is the set up in my Valiant; I have had problems with the timing in the past. I had set my timing to 32 degrees and the car ran fine, until I had some mileage on components in the car, then it developed a miss. I went through the entire system and discovered a lot of slop in the distributor, went to the salvage yard and found a fairly new Mopar electronic distributor, so I converted the car from Pertronix to Mopar ignition with an orange box and also put a new set of wires on the engine as the ones on it where beginning to break down. I again rest the timing to about 34 degrees. Now that the car is back on the road I am discovering I am still having issues. The car still wants to diesel some, we do have reformulated gas and I run 93 octane, if I back the timing down to a place that keeps the engine from rattling/dieseling, I have a power loss, the car just does not feel as strong, plus the car has been popping and backfires even though the car has been warmed up. Plus I have also noticed a low speed miss or roughness that smooth’s out when you tromp the go pedal and is gone at hi-way speed. I am going to check the plug wires and pull the plugs this weekend and see if I can get any more info from the engine. I get roughly 17 lbs. of vacuum at idle which is set at 900 rpms. I need ideas or suggestion of what direction I need to go. I set everything with a vacuum gauge and dial timing light. I feel like I am missing something or not see the problem correctly any idea or help would be great thanks....

Pete
 
First we need to define your term "dieseling." It sounds to me like you are NOT having "dieseling" problems but rather "pinging, knocking, or detonation."

Cam timing, compression ratio, timing advance curve, total advance, engine operating temperature, and fuel ratio and octane all play a part.

Other things that can affect ping are a heavy car, high gearing, "lugging" the engine, and OIL CONSUMPTION such as through the valve guides

One thing I'd do, is check out that distributor to see just how much/ how fast it is advancing. You using vacuum advance? This happen at medium/ part throttle? Try pulling the vacuum advance off for awhile

'Back in the day' I used to routinely run more like 38-40, sometimes 42 total advance
 
your cam is crap but that's what you got so reach in the end of the vacuum ball on the distributor and stick a allen wrench up it and adjust you advance and that will solve your problems and make sure your weights are not seized .
 
The new distributor could be off a tooth.
Put the motor on TDC, and make sure the rotor is pointing at the front driver side manifold bolt. Total timing at 32-34 is fine. Tune it with vacuum advance plugged.

Other things to check.
Firing order.
Bad cap/rotor.
Bad coil.
Bad ECU/Orange box.
Stretched timing chain.
Carburetor.
 
Pinging is a more correct term, and I have tried the moving the distributor in 2 degree increments to try and rid myself from the ping, when I can get it to stop pinging that is when I lose power. I have even tried changing the advance through the vacuum canister and still have the same situation. I am beginning to think I may need to recurve the distributor and get it tuned for this engine combo. The pinging occurs under hard acceleration. How do you figure out what your car likes for initial advance or does using the vacuum gauge/ idle/ max vacuum combo work the best? What about Degreeing the cam should that be done to help with theses issues?

67Dart273 said:
First we need to define your term "dieseling." It sounds to me like you are NOT having "dieseling" problems but rather "pinging, knocking, or detonation."

Cam timing, compression ratio, timing advance curve, total advance, engine operating temperature, and fuel ratio and octane all play a part.

Other things that can affect ping are a heavy car, high gearing, "lugging" the engine, and OIL CONSUMPTION such as through the valve guides

One thing I'd do, is check out that distributor to see just how much/ how fast it is advancing. You using vacuum advance? This happen at medium/ part throttle? Try pulling the vacuum advance off for awhile

'Back in the day' I used to routinely run more like 38-40, sometimes 42 total advance
Click to expand...
 
pull the distributor with motor at TDC number 1 look at the slot in the top of the distributor drive gear it should be paralle with the cam when you drop the disributor in it should line you up with number 1 plug your drive gear may be out a tooth or 2 one way or another ask fstfish66 he was having a problem with his 340 blower motor and thats what it was the drive gear was one tooth out took the miss out and gave him all he needed
 
900 RPM is too high for idle. That's your "diesel" problem right there.
 
if you didn't notice any change through the canister make sue it not ripped and is working properly you should have noticed some change run your idle up to 1000--1200rpm do you have a stale torque in this and headers what gear and where is your vacuum hocked to full port vacuum or above plate vacuum.
 
67Dart273 said:
If he can properly set the timing it doesn't matter what "tooth" the distributor is on.
Click to expand...

True, and you can drive your car with 20psi in the tires,but it doesnt make it right.
What I was reffering to was the Dist/Oil pump gear. To be installed right,it should face the no.1 spark plug.
 
The car runs and drives, I drove it this morning to work and it sneezed hard and now the miss is even worse than before. Time to do a compression check, then ohm the plug wires, check the plugs......then look at the distributor again....let you all know if I find anything...
 
The car went into the garage about 2 1/2 years ago after a lengthy service; the trans in the car gave up the ghost. It has taken me all that time to get the parts for the conversion to a 4speed from a three on the tree. This is the first time the car has been back on the road since the conversion. The engine was built about ten years ago and still has not had that many miles put on it, everything in the engine was replace. So I am not sure what is causing this, but it seemed to start just before the trans took a dump and I kind of just put the car away because I didn't have the money to fool with it. I have looked at it several times while parked, but without being able to drive it, it was kind of hard to diagnosis. I did replace the wires, cap, rotor and the distributor, along with installing an orange box ECU. So if anything it has to be in the ignition or fuel delivery and was looking for ideas or suggestion. Again this weekend I will do a compression test and check all of the components. Thank again...
 
check your carb gasket but you say it backfire through the carb right? have you cleaned the carb sound like it could be lean and or becuse it is a purple shaft cam you might have rounded out a lobe how many mile do you think you have on it since the over hall .
 
Wow, maybe 8000 to 10,000 miles at the most...could be more but not by much...it has seen a lot of hi-way miles as I drive out of town to shows...not much in town driving...

Oh and one more thing even with the car running rough, when you mash the gas there is no hesitation or backfire...but if the car is not fully warmed up it hiccups....like I said I am just not seeing something.....


robert 68 cuda said:
check your carb gasket but you say it backfire through the carb right? have you cleaned the carb sound like it could be lean and or becuse it is a purple shaft cam you might have rounded out a lobe how many mile do you think you have on it since the over hall .
Click to expand...
 
You might pull the metering rods/ pistons out and see if they are stuck or gummy
 
Johnny Dart said:
True, and you can drive your car with 20psi in the tires,but it doesnt make it right.
What I was reffering to was the Dist/Oil pump gear. To be installed right,it should face the no.1 spark plug.
Click to expand...

Com'on buddy. What "tooth" the drive gear is on hasn't got a thing to do with how the engine runs. It also has nothing to do with how much pressure is in the tires, a very poor comparison.

What you implied in your post is, that if the gear isn't in right, the engine can't be properly timed. Not true.
 
Hadn't thought of that....thanks...

QUOTE=67Dart273;1348397]You might pull the metering rods/ pistons out and see if they are stuck or gummy[/QUOTE]
 
Do a compression test. It sounds to me like it may have a burnt valve. Also, when these carbs were factory equipped (the Carter versions anyway) they would be rebuilt fairly regularly. You may just have something in the bowls or the metering circuits. Get a rebuild kit and go through it if the compression test is good.
 
I also was think about that as one of my possible problems....thanks


this the engine in all it's 200 hp glory....

SN850020.jpg
 
67Dart273 said:
Com'on buddy. What "tooth" the drive gear is on hasn't got a thing to do with how the engine runs. It also has nothing to do with how much pressure is in the tires, a very poor comparison.

What you implied in your post is, that if the gear isn't in right, the engine can't be properly timed. Not true.
Click to expand...

So what your saying is that you can just drop the Dist/Oil pump gear in any old way you want ?

Interesting.
 
64X2 said:
I also was think about that as one of my possible problems....thanks


this the engine in all it's 200 hp glory....

SN850020.jpg
Click to expand...

Do you have a Elec or Mech fuel pump ?
What is your fuel psi set at ?
Is your Orange box (ECU) properly grounded ?
Did you replace the coil ?
Bad fuel ? Did you drain the old fuel ?
 
Mechanical pump set at 5 psi, ECU not only grounded but use Dielectric grease to keep a good connection and cut down on corrosion, Blaster 2 Coil, and yes I did use the old gas in the tank, there wasn't much in there enough to get to the gas station and I put STP gas treatment in also to help with any sour fuel issues.


Johnny Dart said:
Do you have a Elec or Mech fuel pump ?
What is your fuel psi set at ?
Is your Orange box (ECU) properly grounded ?
Did you replace the coil ?
Bad fuel ? Did you drain the old fuel ?
Click to expand...
 
Since it is a mechanical fuel pump, I would ditch the regulator, fuel pressure gauge,glass filter. No need for it. It will take some of the parts out of the equation.

Instead run a factory type fuel line with a good metal (Wix) gas filter.
 
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