1990 740A Coil Replacement with EI and Prestolite Distributor

[toddsull]

I have vp 740A DP in a 1990 Wellcraft Nova. The engine won't rev over 4,000 rpm. Replaced gas/water filter, carb filter, plugs, rotor and cap and plug wires. Still no love....
The coil is hot to the touch. The coil and the replacement coil are obsolete and I'll have to buy an aftermarket coil. I believe the coil has no external resister and is a straight 12 volt, but I haven't tested it as it's an hour away in the marina.
Can anyone make a best guess as to whether I should buy a standard 12 volt coil or one with an internal resistor? Or, buy both, test for 12 versus 9 volts on the boat and install the right one (hate to buy 2 and have to return one). Any help is very appreciated.
Quick question: is 4,600 rpm limiter low for a big block 454? Could that be the problem? Can the rev limiter be simply bypassed.

 

[Scott Danforth]

Its not your coil. All coils get hot to the touch. In fact it rarely ever is the coil. Such as only about 3 coils out of a million changed coils were actually bad

Nothing special about your coil, however replacing it would simply make your wallet $40 lighter

and since the coil is electrical, there is no returning

However if you bent on replacing, the coil specs are in the factory service manuals

Back to your low WOT
Check your distributor cap and rotor
check your compression
check your fuel pressure
Check the contents of your fuel filter
Check all the other items in the sticky for low WOT

Feel free to disconnect the rev limiter, however it should be set to 5100 from the factory

4600 rpm is low however with the low compression, mild cam, and mediocre heads, its where the stock gen V motor starts to run out of breath.

 

[toddsull]

Thanks Scott! I’ve only replaced one coil in a car - and that was my fault. This has been driving me nuts and with the boat an hour away, it’s not like I can fire it up in the garage/lol. I’ll check the sticky and see if I’ve missed something. TJS

 

[toddsull]

Had the boat out last night to work on it. I’ve checked/replaced rotor/cap/plugs/gas-water filter/carb filter/wires, etc. It has a newer (3) Holley marine carb. On it. still cutouts about 3,800 rpm. I have not checked the fuel pressure. It sounds and feels electrical (whatever that means).... I’ve decided to replace the Prestolite distrutor. After looking at the different aftermarket distributors and their applications, I’m not certain of the correct distributor to order as no one references a Volvo Penta 740A duoprop with electronic ignition. It’s just a Chevy 454 BB. Several manufacturers refer to a “tall deck” versus ?.
Can anyone point me in the right direction? I’d like to order a full kit, new distributor, coil and it will require new plug wires.
Thanks for your help! TJS

 

[Bt Doctur]

check the fly weights in the dist, they may be rusted in retard position and not advancing

 

[toddsull]

I so wish I was closer to the boat... I'll check the weights (didn't do that...). I'm thinking of just ordering a new distributor, but having a challenge selecting one. I'm thinking of the D.U.I., part 314-M12720BK. However, on SUMMIT, the DUI application chart only goes to 1988. I have a CCW chevy 454, 1990. I can't seem to verify from Summit or Jegs if that DUI will work for a 1990 454. Any recommendations for a distributor change? Thanks again.

 

[mspence]

I'm watching this thread. Diagnosed a broken advance spring on my 1992 VP 740 DPC yesterday. Would like to replace the springs, but can't find the advance curve for this motor. The DUI stuff was recommended by a friend but I want to be sure the advance curve is correct for this motor. I pretend that my motor lives on a dyno, and treat the timing accordingly

 

[Lou C]

It looks like the weights could be rusted in place. You see that foam looking thing in the center of the dist. shaft? that's a foam oil sponge of sorts, you are supposed to add a few drops of motor oil to that every season. Looks like yours has never been oiled. I'd try to free up those weights before changing distributors. You already have an electronic distributor (mine is similar but with points) so I'd for sure do that first. Then oil it once a season!

 

[GA_Boater]

I'm watching this thread. Diagnosed a broken advance spring on my 1992 VP 740 DPC yesterday. Would like to replace the springs, but can't find the advance curve for this motor. The DUI stuff was recommended by a friend but I want to be sure the advance curve is correct for this motor. I pretend that my motor lives on a dyno, and treat the timing accordingly

What you're watching is paint dry. The OP made his last post in this thread a year ago and must have fallen off a cliff. Haven't seen him since.

Closed.