Mechanics

DODGE TRUCK ENGINE PROBLEM

1979 Dodge Truck

Engine Performance problem
1979 Dodge Truck V8 Four Wheel Drive Automatic 30000 miles

The engine idles fine until I shift the transmission into gear. The engine dies unless I manage to maintain 1000 rpm or more. The following parts have been replaced: spark control module, spark plugs & wires, balast resistor, distributor, pcv valve, and carburetor. I removed the EGR valve and installed a new gasket and used a blanking plate in place of the valve--the engine still dies when put in gear. It is a 360 4 bbl. The torque converter stall speed is 1800 rpm (torqflite 727 tranny). The carburetor came from a 360 of the same vintage which was used in a vehicle thar plows snow and performs great. The ignition timing is set at 10 deg. Btdc. The dying started all of a sudden as if a switch had been actuated. Prior to that, the vehicle ran fine.


does anyone have a clue as to what else I can check?
Avatar
Fred Ranta
October 10, 2009.




I just love this. I hope you have fixed it. But if not, let me know, cause I wanna help. OK I started in Dodge, then.

Tiny
Ch112063
Oct 17, 2009.
No, I have not solved the problem.

Tiny
Fred Ranta
Oct 18, 2009.
Hey, how are ya? Sorry it stalls all the time. If you wouldn't mind, I would like you to give me some info.
When it's cold, warm, or completely hot. Is there any difference?
Also, do you have a lean burn system(computer on air cleaner?
Did you put a brand new control unit in from Chrysler(Mopar_)?
Was it the rectangular one with the hexagonal shaped plug> With a screw in the middle of the plug? Small, mounts on sheet metal, not air cleaner.
Tell me anything you have done since the 10th.
IOs there any vacuum advance > or is it vacuum at the Computer?
Sorry, but just a few more, cause it is a lot more difficult to judge things you cannot see or hear.
These parts, all good parts, all good Mopar parts or some cheap and some Mopar?
Do you know if your trans has lock up or not? And is it a California built?
You drove the truck this carb. Came off or no. You heard? Why, in your experience makes you sure the engine is shutting off electrically, or could it be a fuel thing, with a hard restart? Or pedal to floor to restart(unload the choke)
I will not bother you if you are not too concerned, and please excuse me for seemingly intruding on your knowledge. I m, ay need some part numbers too. Why 10 degrees, is the truck still with a engine specs decal?
Later. New Distributor and coil wire?
Just from your story, it sounds like an off idle or float thing. But the advance for timing has to be either manifold or ported, according to ststem, state, and carb.
OK

Tiny
Ch112063
Oct 18, 2009.
1 I connected my timing light before replacing any of the components and ran the engine. The spark became intermittant every time the vehicle was placed in gear. The new/rebuilt components eliminated any disruptions in the spark.

2 It is not an electronic lean burn engine--the spark module is located on the inside of the left fender rather than on the air breather housing or tucked under the top of the left fender.

3 The vehicle is equipped with an electric fuel pump (Carter RV pump) mounted on the frame rail. The fuel pressure is 4 psi.

4 The stalling occurs under all conditions except when the fast idle cam is set on high. Temperature has no effect.

5 The torque converter has no lock-up feature. The truck is not California build.

6 The distributer has a vacuum advance attached to ported vacuum (not manifold vacuum).

7 The engine starts easily no matter what.

8 The carb (Holley) was replaced with an Edelbrock (Carter AFB). Both behaved exactly the same except the Edelbrock provided better power with full throttle operation. Bear in mind the problem showed up all of a sudden as if something switched to cause this.

9 Ignition timing is set to 10 deg. To compensate for operation at 8500 feet elevation and to accomodate for the RV cam.

10 A set of new wires was installed.
AD

Tiny
Fred Ranta
Oct 18, 2009.
Thanks for being precise. It was ok after the distributor and ECU was replaced so I would look there. Did that have the dual pick ups, the start and run? Maybe the gear, shaft, or drive gear in the engine loosened up or the chain loosened up also but you would know because you drive it all the time. You mentioned cam? Do you have a 3/4 cam in it? And did the vacuum diaphragm in the dist. Look ok. I know that the clearance had to be right in the two pivk ups and a brass feeler gauge was nec. Matbe as the dist. Speeds up it also is being thrown up, making better contact with the rotor and tower and it is because the drive gear took out the reman dist.
At least it's good while the throttle is opened a little. No idle solenoid right?
I think it's primary ignition and the dist. Or ECU are in on the deal. I hope you find something. Or give it some idle and a couple more degrees. I will think about this and talk to Sudsy, I used to do all his work, 79 truck. 360 and he's still plowing with it. Good luck Fred, please tell me if you find it. And if I see or remember something I'll let you know.

Tiny
Ch112063
Oct 18, 2009.
Joe,

Thanks for spending your valuable time on this seemingly simple problem. There is no idle speed solenoid as you suspected. The cam is what is advertised as an " RV" cam. I do not know the specs. The engine has about 10,000 miles on it. It was replaced with a crate engine just prior to my being involved with the truck. Oil and filter changes have been performed every 3000 miles. The vacuum advance in the dist. Works fine--no excessive play and it holds vacuum. There is only one pickup coil. The centrifugal advance also checks out ok.

I have been reparing vehicles since 1967 and have some diagnostic equipment for the newer vehicles including ABS. I certainly was mistaken when I figured this problem would be simple to solve! In that time I have rebuilt roughly 75 engines (Mopar 318, 360, 440, 225, 3.8, GM 283, 327, 350, 454, 307, 3.8, 3.0, 235, 265, 2.5, Ford 289, 305, 351, 170, 390, 460, 3.8, 8N, 9N, Toyota 22R, 3.1, MGB, MG Midget, Triumph, VW 4 cyl air cooled, Datsun 4 cyl, Minnesapolis Moline Model 445, and others I can't remember. All of these rebuilds have lasted well over 100,000 miles each.

Tiny
Fred Ranta
Oct 18, 2009.
Hey Fred, no problem. Why is my time so valuable? I spent an hour answering your response. I will wait til tomorrow. To see if it got through. I saw a schematic and a truck. OK I know the response will be found. The website is reliable, If not I'll answer again tomorrow. Your truck is going to idle, no matter what. No surrender.

Tiny
Ch112063
Oct 19, 2009.

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