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Engine wonbt go over 3000 rpm

J

jeffsboat

Contributing Member
"One of the engines will not g

"One of the engines will not go over 3000rpm. It was running at 3500 and then went flat during running and now won't go over 3000 rpm. They are 318s 1979 vintage. I am going to pull distributor wires while running to see if I have a bad plug or wire. Could the ballast resistor cause a problem or the ECM?
Thanks,
Jeff"
 
"..." Could the ballast re

"..." Could the ballast resistor cause a problem.."

No or it wouldn't run at all. The ECM could be the problem, but I suspect a plug wire is off or whipped.

Try this:

1. Warm the motor thoroughly and let it idle.

2. Using insulated pliers and heavy gloves, pull each plug wire from the distributor and listen for the loss of rpm. Put the wire back and listen for the rpms to come back up. If you find a cylinder that doesn't respond, change the plug and that wire.

Jeff"
 
"I have the same problem now.

"I have the same problem now. My 360 is a new motor (remanufactured) with about 20 hours on it. Everything was running 100% until this weekend when I couldnt get it over 3000rpm.

I hope it's just a matter of plugs or wires although during the repower, i used new plugs and wires. maybe something came loose?

Also, since the motor was installed, the cranking sound was different than the other motor's sound. Sounds like a locomotive/steam engine just getting going down the tracks. You know that air-releasing sound when cranking? Hard to explain. Anyway, it's been doing that since the motor was installed but has been running great getting up to 3500rpm no problem...until this past weekend. Also, I notice my volts in this motor are lower than the other battery for the port motor. Would low cranking power contribute to this sound ?"
 
"Dan:

You might be getting

"Dan:

You might be getting water into the motor from the exhaust elbows and risers; and even if the parts are new and/ or are in "good" shape. A bad gasket, poorly cleaned gasket surface, a leaking (if you have them) swivel elbow...all can cause water to drip down into the rear cylinder (with log manifolds, the center cylinders with center dumps).

Here's something you can try: At tne botton of the riser elbow is a low point drain. (Don't confuse this with the water jacket drain. There's TWO drains down there.) This one is closest to the vertical gasket surface and is (usually) a 1/2 inch hex size. Use a 6 point socket and try to unscrew them. If successful, put them back in loosely and fire the engine.

Run the engine for 10 minutes then move quickly! Shut her down and pull those plugs out fast as you can. Next--if you didn't feel water coming out--put a paper cup with a tablespoon of Kool Aid dry mix in it below the opening. If a drop of water comes out, you'll see it. (Cherry works best!) Leave it there for an hour or so.

Give that a try and get back to me. We'll work on the other issues next.

Jeff"
 
"No swivel risers on mine.

"No swivel risers on mine.

There are 2 vertical gaskets on my risers...one from the log into the riser and one from the riser to the elbow. I'm assuming you're saying that there is a 1/2 inch plug closer to the log outlet?

If so, sounds like we're trying to see if the gasket that goes between the log and the riser has a leak which would allow water to drip back into the exhaust part of the log which could leak back into the rear cylinders?

wouldnt I see murkey oil if water was leaking back into the motor?"
 
"...":There are 2 vertical

"...":There are 2 vertical gaskets on my risers...one from the log into the riser and one from the riser to the elbow. I'm assuming you're saying that there is a 1/2 inch plug closer to the log outlet?"

It's 1/2 inch WRENCH size and is close to the gasket.

..."If so, sounds like we're trying to see if the gasket that goes between the log and the riser has a leak which would allow water to drip back into the exhaust part of the log which could leak back into the rear cylinders?"

Correct.

..."Wouldnt I see murkey oil if water was leaking back into the motor?"

No. I've had (ah-hem) several leaks, had starter bucking, and never saw milky oil.

Be glad you don't have those God-awful swivel elbows!

Jeff"
 
starter bucking? as in starte

starter bucking? as in starter problems? could this be my problem since I noted in my earlier post that my starting sounds a little fishy...and takes a while to get started but I thought it was due to low voltage.
 
"Didn't know what else to

"Didn't know what else to call it, but when water gets into a cylinder the starter tries to compress it and it..."bucks".

Instead of RRRRRRR you get RRR--hesitate--RRRR.

Bad news!

Jeff"
 
"so the plug that i'm remo

"so the plug that i'm removing...i suppose that leads to the exhaust (center) part of the manifold? It must because if it leads to the water jacket (the outer part of the manifold), of course water will drip/pour out when unscrewed.

sorry...just thinking through this."
 
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