Mechanics

MODELS RV 440 PINGING

1977 Dodge Other

Engine Performance problem
1977 Other Dodge Models V8 Two Wheel Drive Automatic 25000 miles

Hi, My 1977 RV dodge 440 engine is pinging really bad after it warms up (about 10 miles). I lose power and can barely go up a small incline or over 40 mph on the freeway.

The rebuilt engine has 25,000 miles. The Edlebrock carb was rebuilt and adjusted. All vacuum lines checked. Timing was in spec at 7.5-8 TDC. Vacuum advance is moving. Spark plugs and wires changed. Tried various unleaded gasoline brands, tried octane booster. Changed gas filter.

None of the above has made any difference. Can you give me some clues on what else might be causing the problem? It obvious now that it is not an obvious problem.

Thank you for all suggestions or anything I can try to zero in on the problem.
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Zajacik
December 21, 2009.




EGR valve might not be opening causing the engine to detonate/ping-open it up and investigate for excessive carbons

Tiny
Rasmataz
Dec 21, 2009.
The RV is registered in Oklahoma and I don't think one is required. I will look into it though. Thanks.

Tiny
Zajacik
Dec 21, 2009.
The EGR came about in 1973 on all american cars it should have one. All check exhaust system for excessive backpressure being caused by a clogged catalytic converter

Tiny
Rasmataz
Dec 21, 2009.
About 2,000 miles ago I had a complete set of dual muffler and pipes installed. Could they have put the wrong ones on?

Tiny
Zajacik
Dec 21, 2009.
Disregard the mufflers/pipes-are you running hotter than normal temp? Have you investigate the EGR valve

Could also be carbon deposits in the cylinders, lean fuel misture and wrong sparkplug heat range
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Tiny
Rasmataz
Dec 21, 2009.
I will investigate the EGR valve. The temperature runs 185-190. Plugs and wires were changed about the time the problem started. Can't remember exactly. Is there a recommended plug? Thanks, Ray

Tiny
Zajacik
Dec 21, 2009.
I will investigate the EGR valve. The temperature runs 185-190. Plugs and wires were changed about the time the problem started. Can't remember exactly. Is there a recommended plug? Thanks, Ray[/quote: 6bd433cd20]

I pulled a plug and the color is reddish/tan. It is a Champion RV15YC4. Is this correct? I can't find the EGR valve. The engine was rebuilt in TN before I bought it. Is it possible it was not put on?

Tiny
Zajacik
Dec 22, 2009.
I wanted to give some feedback as to the problem with my Dodge losing power. It was the " spacer" plate between my intake manifold and my carb. The plate had two cracks in it which apparantly expanded when getting hot.

Now I have power but I still hear a " pinging". Timing was checked and determined ok. My mechanic took a test drive with me and said I was hearing the noise from two leaks from the exhaust manifold gasket and to me it was a " pinging" sound but to him an exhaust leak.

After fixing the spacer plate problem my car is running near 200 and not the normal 180. On this I will check my thermostat.

Thanks for everyone's suggestions.

Ray

Tiny
Zajacik
Jan 7, 2010.
Having orked on these beasts during that time period there are a few things that you may check into. THey had bad mufflers during that time period and they would slide internally and block the exaust, especially under heavy load such as going up a hill. If you throw a vacuum guage on it and your running about 15" at idle it's to low and you probably have a blocked exaust. Yu may have to back off on the timing as well as that engine has a 10'1 compression ratio. But also the valve seals were mostly nylon and would let oil into the cylinder, that slows the burn rate and causes pinging as well. Putting positive valve seals on this would help immmensly. I forget if there is an egr valve or not as it's been so long as it may not have one due to it being a truck. But you can take it and clean it out and make sure it works correctly. Also if your RV blows some black smoke when you're warmed up then you might try getting some smaller jets/metering rods for the carb as they are all set to run rich from edelbrock. Or maybe you can slow the metering rods from opening so quickly so it wil stop the pinging as well.

Hmac300
Feb 22, 2010.

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