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Crusader 270hp Stalls below 1800rpm

FastFred

FastFred

Member
Any Ideas? Please help!

My Starboard side eng dies below 1800rpm.
Stats:
Crusader 1988, 270hp (GM 350cid)
rochester 4bbl carb. (recently rebuilt by a pro, not me)
Twin engines, port side runs fine
Shared fuel tank, separate fuel pick-ups, spin-on filters, etc
Prestolite Electronic Ignition (recently replaced), mechanical advance
Fresh water cooled

It had run fine in the morning on the way out of the slip, and out to the fishing grounds. Time to head home...Engine starts if I goose the throttle, then it stalled when I reduced the RPMs. I warmed up the engine by running at 1800-2000rpm, temp 160-180*, but as soon as I try and idle it down to put it in gear, it stalls. On the way back to the dock yesterday, (one time)I was able to get it in gear and goose it up onto plane, and run. It ran fine on plane at 2900-3000rpm for 15mins or so (tops out around 4000rpm, although I never run it wide open to conserve fuel). I came down off plane, and it stalled again. I will still restart, but only if I run it above 1800rpm. Any ideas?

Thanks in advance.
 
Please define "stalls below 1,800 RPM".
Is this engine stalling as in operating at or below 1,800 rpm ??? ....... or is it stalling as in making the transition from under 1,800 rpm to above 1,800 rpm?


I'd first see where Stbd engine BASE advance is, and also check the progressive ignition advance. Compare this to the Port engine ignition system advance.

With twins, you'll have the option of swapping some components as for your P of E (process of elimination).
Perhaps swap carburetors, and see if the issue changes engines.


You mentioned Prestolite Electronic Ignition. Is this one of the Hall Effect units like the Pertronix?
If Hall Effect, some of the sensor units are very sensitive to correct alignment with the magnetic unit.
Check the distributor shaft for excessive play.... up/down, and side to side.


.
 
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RicardoMarine said:
Please define "stalls below 1,800 RPM".
Is this engine stalling as in operating at or below 1,800 rpm ??? ....... or is it stalling as in making the transition from under 1,800 rpm to above 1,800 rpm?
.
Click to expand...

I believe I know where the confusion is with my earlier post...

I have one (1) binnacle with two levers. Each lever controls the shift and throttle of one (1) engine. As opposed to some boats with two binnacles ie: one for shifting gears and one for throttles.

My engine runs fine at or above 1800RPM

My engine stalls and dies when I try and run it below 1800RPM. Being IN or OUT of gear does not matter.

In order to engage the shift linkage, I must return the shift/throttle lever to idle (800-1000RPM) before shifting. By returning the throttle to idle, the engine quits before I can engage the shift linkage and get her moving.

And YES, I suspect a carb problem as well, but thought I'd ask here first before willy-nilly swapping parts and taking stabs in the dark.
 
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FastFred said:
RicardoMarine said:
Please define "stalls below 1,800 RPM".

Is this engine stalling as in operating at or below 1,800 rpm ??? ....... or is it stalling as in making the transition from under 1,800 rpm to above 1,800 rpm?
Click to expand...

I believe I know where the confusion is with my earlier post...
Click to expand...

Fred, if there was any confusion on my behalf...... it was that I was unclear as to what/how you were defining stalling.
I was questioning this because there could be one of two concerns.

If the transition from low speed fuel metering to high speed fuel metering was causing the stalling, it may be related to the carburetor's accelerator pump function.
If the transition was not the issue, then yes..... I'd look into the carburetor's fuel metering system.

For the cost of two new carburetor base gaskets.... you can swap these as part of your P of E .


.
 
Thanks Rick.

(not being a wise-ass here, ok?)

Did my second explanation clarify my problem?

I appreciate all the help from the knowledgeable folks here. I think I'll go down to the boat today and swap the carbs and see if the problem follows. If not, I'm thinking 'cap and rotor'

This is the electronic ignition module that I recently installed.

http://bpi.ebasicpower.com/p/BPI112...for V8 Prestolite Screw Down Cap Distributors

This solved a "no start" issue that I recently had on my Port engine... Long story... but it might give some history...

Separate (maybe) issue from last week...

Port engine would turn over, but wouldn't start

Replaced the spin-on fuel filter... Started up instantly, ran around the canal and harbor for two hours. No issues. Problem solved (or so I thought)
Next day, tried to go fishing - Same engine wouldn't start
Changed the spin-on fuel filter (again) still no start. Cranked it too much, smoke coming from starter area.
Removed carb. Had it rebuilt by a pro. Reinstalled carb. Still no start.
(Now thinking I have a voltage problem)
Replaced Port starting battery with a Marine AGM Group 31 from Sears ($300. battery) Still no start. Starter smoking again.
This time, I was working in the dark of night, and after cranking it, I noticed that the smoke was coming from the electrical linkage between the solenoid and the starter. It was glowing RED! (Thinking that starter is robbing too much voltage from coil due to bad connections/short)
Removed starter, had it rebuilt by a pro. Reinstalled starter. Cranks like crazy now, but still no start.
Removed cap and rotor, sanded the terminals with fine wet/dry (dry of course) engine started instantly! Problem solved!
Went to go fishing the next day, no start again. WTF?
Installed new cap and rotor. Still no start.
Swap carbs from good engine to bad. No start. Starboard engine starts instantly. Left the rebuilt carb on the Starboard engine.
Decided the problem must be in the area of the distributor cap, since tinkering in that area gets it to start - sometimes
Started swapping parts from the good engine to the bad, one at a time...
First the coil wire - no start
then the coil - no start
Then the electronic ignition module. Started instantly! Hooray! Found it!
Purchased a newer version of the EIM (locally) - the same one in the above link.
I left the old EIM in the Port engine since it was already installed and working, and installed the new EIM in the Starboard engine. Now they both started instantly! Hooray! Let's go fishing!
One week later - Friday - 2 days ago - Went fishing. Both engines run great all the way to the fishing grounds. OK, time to go home now... Port engine will only start with the throttle up, and dies below 1800rpm - See original post...
 
Fred, since this is a Pertronix wanna-be...... I would swap this out prior to the carburetors.
I am very much against this type of Hall Effect electronic triggering system.
There are issues with these cheesy units. :mad:


BPI112003.jpg



Fred... when doing a P of E...... it's best to do it systematically and methodically.... and ONLY one item at a time.

People who toss all kinds of parts at an issue all at once, are often left with no idea whatsoever as to what fixed the problem.

These guys end up being the ones who do not gain the otherwise knowledge of what/how the problem showed it's ugly face, and/or what the actual cure was.

Was it the seasoning salt that I added.... or was it the garlic that I added... or was it a little of both? :eek:



.
 
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The link I posted was not exactly the part I installed. My mistake. I installed the Petronix brand version of the EIM. It just looks like the one in the link I posted.

Also, I'm very methodical when it comes to changing or swapping parts. I always change one at a time, then test. The previously posted troubleshooting tree that I used probably indicates that.
 
Problem solved!!!

I spent the day down at the boat and swapped parts until I found the problem. Here's what I did:

As advised, I first swapped the EIM from the good engine to the bad engine. Still no start.
I swapped the carb from the good engine to the bad engine. Still no start.
Purchased a new distributor cap and rotor. Installed them. Still no start.
Swapped the coil wire. Still no start.
Decided to swap the coil... Removed the coil from the 'no start' engine, and installed it on the good engine. Restarted good engine, no problem. Went to install the known 'good' coil on the bad engine, and I noticed that the mounting plate was very corroded. Thinking that the mounting plate may be used as the ground for the coil, I took some sand paper to it, then coated it with electrical grease. Mounted the good coil on the bad engine, and she started right up!!! So, it was a corrosion issue between the coil and it's mount that kept the engine from lighting off.

Thanks for all the good advice folks! Much appreciated!

Now...Does anyone know anything about Jabsco Remote Controlled (joystick operated) spotlights? I need a schematic. Mine will only turn left, and will not turn right.
 
Since no two of these triggering units are exactly the same, so be sure that you re-set the ignition timing after having swapped these components.

And not just BASE advance.... look to see what the progressive and TA are doing as you increase RPM.

BASE advance is BASE advance all day long!
We fire up on BASE advance, and we idle on BASE advance....... and that's about it.

The progressive and TA are much more important.
While "Initial" (aka BASE) advance and timing does and should predicate the progressive and TA, it may not if something is wrong with the advancing system.



.
 
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You wrote:

"Decided to swap the coil... Removed the coil from the 'no start' engine, and installed it on the good engine. Restarted good engine, no problem. Went to install the known 'good' coil on the bad engine, and I noticed that the mounting plate was very corroded. Thinking that the mounting plate may be used as the ground for the coil, I took some sand paper to it, then coated it with electrical grease. Mounted the good coil on the bad engine, and she started right up!!! So, it was a corrosion issue between the coil and it's mount that kept the engine from lighting off. "

This is a classic case of improper co-incidence thinking. Grounding the mount for that coil had nothing to do with your no start condition; you simply got a flooded engine running at last. (Waiting over night would have done the same thing.) And with all that parts swapping, all you did is confuse yourself and make incorrect conclusions. (Been there, done that--especially when I was too tired and frustrated to think straight.)

Here's what I'm convinced is your problem: The carb is flooding! It's okay under load since the amount of flooding is not enough to upset the power delivery (though a Flo Scan would notice it). But when you throttle back to idle, the excess gas loads her up and down she goes.

Now that you've swapped carbs, one of two things will happen: Either THAT motor will screw up on you, or the flooding condition will go away (thanks to jostling the carb about, the gods making fun of you, etc.)

Jeff
 
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2X on the "Mounting plate corrosion" having any relevance to the issue.

I reread the whole thread a few times and still have conflicting "data" on which engine has the problem and which carb is on which engine.

If the flooding was the issue, i would think you could smell the richness very easily...besides the carb's float, needle, and seat, it could also be a bad fuel pump adding raw fuel into the primary via the "sight tube". The sight tube will dump into the primary on the side the fuel line connects from (starboard on an inline installation).

I would suggest a thorough visual inspection and then go thru and verify the mechanical condition of the engine, the ignition functions properly, and the fuel system is healthy...

BTW, I'd have used "control box" vs "binnacle"...
 
Agreed. I received the same feedback from other 'motor head' friends today about the coil being grounded through the case. they lead me to believe exactly what you guys said, that the case IS NOT the ground for the coil, and that I possibly disturbed something else while swapping parts, thus causing it to start. I haven't been down to the boat to try her again, but I now believe that the problem still exists, whatever it is, and that more troubleshooting will be required. I'll report back my findings.
 
An ignition coil case or casing does not necessarily need Negative continuity for the primary side.
The primary side is pretty much captive via the power source and triggering mechanism.


circ_ic.gif
ignitioncoil.jpg



The secondary High Voltage side has plenty of spike voltage to jump an otherwise poor case or casing Neg connection.

I'm not suggesting that this is un-important, but I believe that it's unlikely to be the cause of poor secondary voltage output.

Thoughts????




.
 
Just the opposite...if the primary winding is shorted to the case, the coil won't fire if the case is grounded.

All three terminals of the coil should be isolated, electrically, from the coil's shell.
 
makomark said:
Just the opposite... if the primary winding is shorted to the case, the coil won't fire if the case is grounded.

All three terminals of the coil should be isolated, electrically, from the coil's shell.
Click to expand...

Mark, if the primary windings are contacting the housing/casing, we've got more serious coil issues.

The primary windings should be isolated from the housing, and should not allow for coil saturation until the triggering device says so..... yes/no????


circ_ic.gif
 
Thank you all for the great information about the workings of the coil. Very informative!

I was down in Cape May yesterday where I keep the boat, and as usual, I stopped by to check on her and run the engines. This is something I typically do when I'm in the area. It was very cold (35*) and both engines were slow to start, as they always are in the cold, and when they haven't been run in a week or so, but they both started and ran just fine. I ran them in the slip until they reached operating temperature without even a hiccup. So, with that being said, it's not really possible to do any further troubleshooting until the problem shows itself again.

However, maybe you guys can help me gain a clue to a possibly related issue...

The issue we've been chasing is on the starboard engine. Since I bought the boat (used) I've had issues with the tachs not reading correctly. But for now, let's just deal with the starboard side, since the port side is currently not misbehaving. Symptoms: The stb tach reads 6000RPMs at idle, and as throttle is increased, the tach increases as well. It's reading 6000 when the engine is only turning about 1000 or so, judging by my ears, and by comparing the sound and throttle position to the port engine which is reading normally. Here's the odd part... when the engine was acting up (see original post) and would not stay running below 1800RPMs, the tach was acting and reading normally, and correctly. After chasing the problem, and now that the problem has gone away, the tach began reading improperly again (6000 @ idle).

So when the engine is running badly, the tach works. When the engine runs fine, the tach is wrong.

Does the give you guys a clue as to what might be happening with the ignition on this engine?

Not sure if it matters, but the tachs are from 1988 and are made by Tempo.
 
some tachs have a switch on the back which allows you to use it with a 4, 6 or 8 cylinder engine. you might want to check to see if it has one and is it set on the right setting.
 
1. I've heard of bad tachs CAUSING engine problems, so you might try disconnecting it temporarily and see.

2. What are you doing running engines IN the water at this time of year? It's supposed to go down to single numbers tonight in Allentown, PA (only three hours away). Your FWC system may be okay with that, but anything in the raw water circuit will be placed at risk.

Jeff
 
Docksidemarineservices said:
He should use Non-tox on the raw water side as to not pollute the water when re-fired in the spring.
Click to expand...
Chris, I agree! We do not want E/G endangering our environment.

However, I was referring to this:


missnancy said:
Run the non toxic through the fresh water side and make sure the sea cocks are all closed..........
Click to expand...
For me... and in my silly opinion only......... there's the sea water side, and there's the closed cooling system side (of which is sometimes referred to as Fresh Water side).
I was commenting on the Non-Toxic A/F being introduced into the "fresh water side" (aka Closed Loop side).


.
 
OK, FYI, the boat is in a salt water slip. water temp is about 40* or so, so it's cold, but not nearly enough to freeze salt water, yet.

Brought the boat back to the home port today in Great Egg Inlet, from Cape May. About a 40nm run one way. The tach started off the day as it usually does, reading 6000RPMs at idle. Somewhere during the 40 mile run, it began behaving normally. I was cruising up the beach at about 20kts, and 3000RPMs where I looked down and noticed it was reading accurately again. Stayed fine for the rest of the journey home. Any ideas what's doing this?

Also, I'm beginning to lean toward my original problem being carb related. I believe she's flooding out, and needs adjustment. Any input on this?

She's being lifted out and blocked up tomorrow.
 
Fred, your erratic tachometer behavior could be caused by one of several things.

It simply may have gone whacko just from age, and is now bad.

Since this style tachometer is pulse sensing, it needs to sense a fairly clean pulse.
The pulse is generated by the ignition system triggering device as it open and closes the circuit..... (I.E., from closed coil saturation (I.E., dwell) ), to open (I.E., field collapse).
Incorrect dwell angle can affect a tachometer, but would also affect performance.
(and yes... electronic ignition systems also require a dwell angle... but we typically don't mess with it).

There may be a cylinder selector switch at the rear of the instrument.
Move this selector back and forth some, and return it to 8 cylinder setting. This might regain continuity.

The tachometer pulse sensing lead will be in your Engine harness/Hull harness and harness connector.
Pull this harness connector apart a few times as to gain better continuity.

Temporarily extend the gray tachometer wires at each engine, and swap them to the other engines (coils), and give it a try.... or swap them from underneath the helm.


.
 
FastFred said:
OK, FYI, the boat is in a salt water slip. water temp is about 40* or so, so it's cold, but not nearly enough to freeze salt water, yet.
Click to expand...

The water the boat is floating in may not freeze but the water inside the hull may....just need to be conservative....

FastFred said:
..... Somewhere during the 40 mile run, it began behaving normally. I was cruising up the beach at about 20kts, and 3000RPMs where I looked down and noticed it was reading accurately again. Stayed fine for the rest of the journey home. Any ideas what's doing this?

Also, I'm beginning to lean toward my original problem being carb related. I believe she's flooding out, and needs adjustment. Any input on this?
Click to expand...

As noted before, the tach's internal connections may be degraded due to age...if rotating the selector switch a few times doesn't make it well behaved, it's time to consider replacements...

If the carb has a flodding issue, no "adjustment" will resolve that....you may have a ruptured fuel diaphram which would dump fuel into the carb's primary causing a flooding issue...pull the yellow "sight tube" off and see if it is wet. If that tube has hardened up, it should be replaced.
 
Now...Does anyone know anything about Jabsco Remote Controlled (joystick operated) spotlights? I need a schematic. Mine will only turn left, and will not turn right
Click to expand...

Is this what you have????

ScreenShot002.jpg

ScreenShot003.jpg

I would start first at the remote joystick. Pull the control head out and check all the tabs for power when you move the joystick

The spotlight itself is not difficult to take apart and inside you will find two very small 12V DC motors with brass gears. I had one gear split and the entire motor had to be replaced.
The difficulty is finding parts and to the best of my knowledge there is only one person in USA who has parts and that is a person in Florida, and worse yet, you may have to buy the entire little motor, and they are NOT inexpensive.

If the brass gear just jumped out of its track due to trying to get the light to move to far one way or the other, you may be able to "hand-fix" it.

I tried to fix the brass gear on mine as it would not turn at all but the gear was split and was just spinning on the motor shaft...could not be fixed and I had to get the entire motor, almost 1/2 the cost of a new light !!!!!


If this is not the type of light on your boat .....well you can certainly disregard this post :eek::eek::eek:
 
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