Ford 351 problems

[gregga]

Hey guys,

I have a ford 351 in my 25' whitewater with a volvo commander outdrive. I have been having a lot of problems with the engine lately. It started off with the bellhousing bearings which required removal of the engine, once re-installed I purchased a new holley 600cfm electric choke carburetor and installed new sierra manifolds and riser and a new coil. but I'm having problems with the boat shutting off. It will run all day on the hose perfectly, and for the first twenty minutes the boat is in the water in runs beautiful but within 20-25minutes of the boat running at idle speed it shuts off. Then itll start right back up and run consistent for 5 minutes then shuts off, then its a little bit harder to fire up again but eventually will and run for about two minutes, then itll take about twenty minutes for it to fire up again. We replaced the coil cause it was getting hot so we thought it was the coil but it still didn't solve the problem. I was thinking maybe its the condensor in the distributor? Any help is greatly appreciated. its been 6 months off the water. Thank you

 

[gregga]

Re: Ford 351 problems

Nobody?

 

[Bondo]

Re: Ford 351 problems

Nobody?

Ayuh,... Right when it Quits,... Is it a lack of Fuel,..?? or Fire,..??

Is it runnin' Rich,..?? or lean,..??

What do the spark plugs say it's doin',..??

 

[gregga]

Re: Ford 351 problems

Haven't checked plugs yet.. will do that for sure!! Seems like an ignition problem to me cause the boat runs fine till it gets up to temperature 20minutes later then just shuts off. then you could let it cool down for 20 minutes and it will start right up! Seems like it could possibly be the condensor in the distributor? I don't know much about fords at all so I'm not quite sure how their ignition system is setup.

 

[Bondo]

Re: Ford 351 problems

Haven't checked plugs yet.. will do that for sure!! Seems like an ignition problem to me cause the boat runs fine till it gets up to temperature 20minutes later then just shuts off. then you could let it cool down for 20 minutes and it will start right up! Seems like it could possibly be the condensor in the distributor? I don't know much about fords at all so I'm not quite sure how their ignition system is setup.

Ayuh,.... you've got 20 minutes to find the Problem,....
A test light, or multimeter goes along ways in Diagnosin' the issue....

I've never had a condenser puke, so I donno,...
But,...
Here's everything you could ever want to know 'bout Points Ignition,...
#1,...
#2,...
#3,...
All found Here....

 

[RogersJetboat454]

Re: Ford 351 problems

Don't let the Irish guy's last name stamped into the valve covers intimidate you. The principles are just the same as the engines that the Swiss guy's name is on, especially when it comes to something as basic as a carburetor, or points ignition.

Have you physically checked for spark when the engine takes its 20 minute break? A $8 spark tester from the autoparts store may help you out, with out getting belted.

 

[gregga]

Re: Ford 351 problems

finally pulled the boat out of storage again to try to tackle this problem. The boat previously had an externally resisted coil but.....no external resistor. So we swapped out the hot coil which was burning up after running for 20minutes to the new accel internally resisted coil which last time I ran the boat after 30 minutes the coil was cool to the touch. Pull the distributor cap off and the cap and rotor look fairly new but the (correct me if Im wrong) ignition module inside the distributor which I attached a picture of, I'm wondering if in the meantime of running an externally resisted coil with no external resistor, burnt out the ignition module? The boat as of right now has a brand new accel coil, brand new plugs, brand new ignition switch. Also the boat gets plenty of fuel so its not a fuel issue.

 

[muc]

Re: Ford 351 problems

The picture you posted is a Prestolite BID ignition module.
This system DIDN’T use an external resister or an internal resister; it was designed to run on 10 to 15 volts.
The most common cause of failure is a bad distributor ground. It is very important that the distributor have a very good ground to the block – might be a good idea to clean up the hold down clamp and bolt.
You should NOT use a coil with an internal resister with this system.
My guess is that you had a coil that went bad and are now adding a second problem by installing the wrong coil.
Some good troubleshooting and specifications are found in the Volvo manual.
Volvo Workshop Manual 507144 Electrical / Ignition is one of them that covers your ignition system.
This ignition module is no longer available from Volvo – it maybe available aftermarket, I don’t know because I try to avoid non OEM parts.

 

[muc]

Re: Ford 351 problems

P.S.
There is a service bulletin ( 28-2-3 ) about leaving the key on with the engine not running.

It is important to understand that the ignition switch cannot be left in the RUN or the CRANK position for
longer than ten (10) minutes without a substantial cool-down period.
The reason for this is:
If the engine stalls or someone turns the ignition switch ON without starting the engine, the distributor’s
ignition module can be in a “stall mode condition, where no trigger wheel tooth is in front of the sensor
coil. When this occurs a continuous 5 amps of current flows through the output transistor in the electronic
module and the high-voltage primary coil. In approximately 15 minutes the output transistor will
reach temperatures exceeding 250? F, causing the coil to overheat. This causes the output transistor to
fail or shortens its life.
Should this condition be suspected for a boat engine that will not run, the following procedure may be
performed to determine if the ignition module is functioning normally.
Prestolite Ignition Module Test Procedure
Before proceeding with this procedure become acquainted with each test and do not leave the ignition
switch ON longer than 1 or 2 minutes at a time.
SET-UP PROCEDURE BEFORE TURNING IGNITION SWITCH TO RUN OR CRANK:
50329
1. Ensure Ignition Switch is OFF.
2. 2. Remove the distributor cap and rotor.
3. 3. Check the air gap A (0.008" +/- 0.004")
between the trigger wheel tooth B and the
sensor C face.
NOTE! Be sure to use a brass feeler gauge. The
sensor face should be parallel with the end of the
trigger tooth. The engine may have to be rotated
to get the tooth in front of the sensor. If the sensor
is cocked, the air gap could exceed 0.016"
and at high temperature, intermittent operation
misfiring can occur. This is due to the effects of
heat on the sensor’s magnetic properties.
4. Rotate the engine manually or with ignition switch so that no trigger wheel tooth is in front of the
sensor face. Ensure the ignition switch in the OFF position. Connect the voltmeter (+) lead to the
ignition coil positive (+) terminal and the voltmeter (-) lead to a suitable ground. Place the ignition
switch in the RUN and START positions. The battery voltage should read 12.2V–13.0V for RUN
and no lower than 9.5V for START while cranking. Turn the ignition switch OFF.
NOTE! If no voltage reading, check wiring from coil to switch to battery, and check for a bad ground connection.

5. Move the voltmeter (+) lead from the coil (+) terminal to the coil negative (-) terminal. Place the flat
of an iron screwdriver against the sensor face. Turn the ignition switch ON. The voltmeter should
read approximately battery voltage. Remove the screwdriver blade from the face of the sensor and
the voltmeter reading should drop to less than 4.5 Volts. Place the screwdriver back against the
sensor face and the voltmeter should read battery voltage. Turn the ignition switch OFF.
6. When the voltmeter reading goes down it means the coil has current going to its primary winding.
When the voltmeter reading goes back up to normal battery voltage it means the output transistor
is not turned on and the module should cause the coil to fire.
7. If you remove the spark plug lead from the coil and connect the Snap-On inline spark tester
(PN YA840) tester (Illustration #50331), you can check the firing of the module by setting the tester
with one side to the center coil tower and the other side to ground. Use a flat blade screwdriver and
move it to and from the sensor face after turning the ignition switch ON. Have the spark gap set for
approximately 0.375" and you should see an arc every time you remove the screwdriver from the
sensor face if the checks in steps 4, 5 and 6 (above) were OK. If no arc appears, you have a problem
with either the coil, cap, rotor or spark plug leads.

 

[gregga]

Re: Ford 351 problems

we do have an extra stock coil.. I will try installing that one

 

[gregga]

Re: Ford 351 problems

installed the new coil today, same one that originally came off the boat and got it to fire up and ran the boat on the hose, would run for about 2-5 minutes and start right back up, messed around witht he air-fuel ratio on the side of the carb ( holley marine series 600) and finally she started to run ok and ran for about 5 minutes then shut off and wouldn't start back up.. Getting sick of this boat. Been 6 months since we have been able to use her. pulled the air cleaner off after she died out to make sure it was pumping fuel and it was very steamy out of the primaries if that means anything?

 

[gregga]

Re: Ford 351 problems

I'm thinking its either got to be the ignition module in the distributor from the picture I posted or Vapor lock? I read somewhere tht some of these 351 setups had vapor lock problems? But also on the same hand if the boat has ran like this (with this carb and 1" spacer) for this long then how all of the sudden could a vapor lock problem arise?

 

[muc]

Re: Ford 351 problems

Gregga,
You have 3 options.
1. Get the tools and knowledge to troubleshoot and repair this yourself.
2. Read the forums and guess at what might be wrong with your boat based on what was wrong with other peoples boats (we call this throwing parts at it).
3. Find a good mechanic to troubleshoot and/or repair it for you.

Most of us are more than happy to help with one of the above.

 

[RogersJetboat454]

Re: Ford 351 problems

Please look for one of these;


Guessing what's wrong usually costs lots of money, with the only benefit is you have allot of spare part's all said and done.
Spend some time DIAGNOSING the problem.