XCAV8

i own a 1989 baja 240 es, with a bravo 1 magnum 454. when i bought the boat it wasn't running right , it wouldn't get on plane very easy.. It had a car distributor, car starter, leaky fuel tank, and the list goes on... i put it all back to marine , all new thunder bolt IV ingnition modules (both parts ,the brain and the one that bolts inside the dist.) took it for a ride still no power, so i desided to change the plugs and wires.. i get to #4 cylinder and the damn wire isn't even snapped on the plug, i pull the plug and its brand new never fired....... so simple so stupid ........ so we take the boat out for a test ride and holy sh_t it runs like a raped ape, jumps on plane and flies like it never has before.. about the time i'm feeling happy that this power problem is finally fixed .
the engine starts spitting and sputtering a bit. we are at crusing speed about 3000 rpm , now it keeps getting worse breaking up backfireing coughing ...... so i notice anytime i hit a trim button or anything electrical it feels like i'm putting on the breaks, the motor seems to want to die and lose power ,when anything electrical is ingaged... so i'm thinkinging maybe it a bad ground???
Any ideas??? any help would be greatly appreciated.
thx

Audiofn

Ground Ground Ground. Baja's are notorious for this. Check your engine grounds first. Especially the one at the bellhouseing or engine mount. Make sure it is real good and not grounding through paint. Good thing you got all that non marine stuff out of there especially if you had a gas leak!!!! Make sure you did not loosen anything up when you did all your replacements. One last thing to check on the power side is to make sure your large nut on the sarter did not loosen up. I have seen that happen a number of times and cause very similiar problems.

JOn

BadDog

Jon's got the basics on that one covered, check all grounds. Several 89 BAJA's with BBC had the wiring harness run across the top of the intake manifold on the odd side. If the crossover gasket in the intake burns out the wiring harness gets very hot and the harness get the "green wire” condition. Basically the wire loses its ability to carry much current and when you draw any current from other power sources your ignition loses the required voltage to fire. This may not be the problem with your boat but inspect the wires running across the top of the intake. Fixed several BBC’s with this problem from late 80’s.

If you are by chance running the stock ignition wires on this boat, Merc had a recall on certain date code spark plug wires from around 88 and 89 for leakage. Same symptom.

Tim T.

XCAV8

thx a ton guys, wow this board is full of great info, what a time saver.......
well now that you mentioned the green wire effect, after we started having this problem we pulled back to the dock and a bunch of boater beer drinking dock mechnics gave me all kinds of advice , so we changed the fuel /water sep, and changed the timing a bit , took the boat back out.. again it ran well for 5-10 min and again the same thing started happening, i noticed that when the boat was running poorly the temp gauge dropped out. but when just running at idle the tab buttons or anything electical did not effect the motor. then this might be purely
conisadince but the bilge pump started going crazy it wouldn't shut off , and looked as if the high water switch was not stuck on.. i changed the intake manifold gasket before i put the boat in the water and there are now no leaks vacuum or other wise.

thx again

Audiofn

Put a voltage guage right to our alternator and ground it on the block. I have seen alternators work at IDLE then when they go to higher RPMS acually play some REAL games with the electrical system. Then Load test your batteries just to make sure they are good and charged up. ALSO check that large lug on your starter again just for Chits and giggles.

Jon

XCAV8

Checked i bunch of grounds cleaned and tightened them , i hot wired the coil to see if it was the feeds to the coil, the voltage on the volt meter reads the alt. is putting out 13.5 - 14.5 volts....
the volt meter does jump down pretty good when i hit either the trim buttons or the trim tab buttons, also breaking up the motor when hitting these buttons under a load. at idle it seems to be fine , except for once even at idle hitting the tab buttons did kind of effect the motor kind of killing it , but not to the point where the motor actually stalls......

Could a bad coil create these systoms ?? i am going to buy a new coil today just to see , it doesn't hurt to have a spare on board anyway..... i am also going to ck the big lug on the starter today... And look for more grounds.... thx everyone for all your help.....

P.S. Audiofn , i Very much enjoy reading about your boat project. Keep up the good work...
Gregg

Audiofn

Greg one thig you can try is make sure your battery is 100%. Then disconnect the "excite wire" on your alternator and see if that keeps it from stalling. Give that a try and let me know what the result is.

Thanks for the compliment on the boat. I hope to hit paint Thursday

Jon

Gearhead99

Sounds like the coil is heating up and breaking down.

Try a coil, it is very easy to try.

XCAV8

Well guys the boat finally ran good, i istalled a msd blaster2 coil and it has never run so good, didn't miss a beat... I Just want to thank every one for there help.......

Now on to the cosmetic stuff thats needs some tlc......

thx again

Gregg