96 260 problem?

[WaterBoy]

OK, here's the deal, I thought the ECU was bad, it acted like it was flooding out, wouldn't take off, just die. So I bought a PCU, ok was told that I need a 56lb reg. ok, bought one. Still will not take off. Just makes some weird clickin noise, I adjusted the linkage to the butterfly so the timing would fully advance before the butterfly opens. It helped some, at least it'll take off now. If you push the peddle half way, it will not take off, the only way it'll take off is to floor it, then it clicks for a second or two and catches and is gone.

Please list things to check, I'll write it down. I know it's not the ECU, I got a new PCU. It also cuts out at about 8,000 rpms, I think I may have a 39lb pump, so I got to change that. Does anyone know if the PCU has a rev-limiter, Emailed Tony, didn't get a response.

Any help would be appreciated, thanks Mtcm for your help also.

Jason

[WaterBoy]

ttt

[Superdave]

What does it sound like, and where, when exactly do you hear it?

[WaterBoy]

You hear the noise when you open the butterfly or open the throttle, it makes a fluttering or clicking sound. If I give it half throttle it will eventually take off, but my dads john boat would be quicker out of the hole. Any thoughts on this?

Jason

[Bill Gohr]

Call me 847-356-3245 847-274-9378,

[WaterBoy]

I'll call you tonight after work, I tried yesterday calling you and didn't get you.

Thanks, Jason

[WaterBoy]

Well, the timing is set right, 25 and 0. What next, I also took the Blue Holley out of the picture, just the bosch is on now. Got the Gaffri dual pryo gauge in lastnight. Today, they would only reach about 850 to 900, so with the stem wheel leaned it to about -25%, pryo reading up to about 1000, stop in the river, wouldn't take off, just died, set stem wheel back to zero, didn't die but fluttered again and FINALLY took off.

Also, today while idling in to the ramp, my tach stopped again, I just put a new rectifier on.


Begining to wish I'd kept the old carb motor.

What else should I check?

Waterboy

[W. Tripp]

Is there a posibility that it could be reeds or that you have a leak around the intake?

[WaterBoy]

I just put a 1" spacer kit on, so got new gaskets there. Reeds looked like new. Thanks though.

It acted this way before the spacer plate also.

Waterboy

[johnnyracer]

Shot in the dark here, but what about the injectors, one hung open or several just spaying ****ty. Just a thought.

Later John

[WaterBoy]

And also another stator. We'll see.

Waterboy

[steve]

My guess is probably wrong but it sounds like you just blew the other side of the rectifier again. You need to get a 25A Rapair unit or check it and the stator. When you blow the hot side it will leak AC to the ECU and the injectors will float open. That makes them run rich. Try checking the rectifier again for opens and shorts. Likely a hot is shorted.

[WaterBoy]

What would be the best way to check a rectifier? To see if it's good or bad.

Waterboy

[steve]

Go to Radio Shack or elsewhere and get a VO meter with a diode ( rectifier) setting. The rectifier on a Merc has 4 diodes, its a bridge type. 2 go from AC ( yellow wires posts) to ground and 2 go from AC to B+ ( +12-14V DC out) or the red wire post. The regulator on top of the motor behind the flywheel regulates how high the voltage will climb and it also can cause problems similar to what you describe but its much less likely to fail.
On the rectifier:
Disconnect all wires 1st.
You will check from ground to the 2 AC posts ( where the yellow wires go) and from B+ out ( where the red wires go and marked with a + sign) to the 2 AC posts.
On each pair of terminals after testing with the leads in one direction , you will swap the leads and test in the other direction. For example if the red probe is on an AC post and the black is to ground, you will now test with the red to ground and the black to the same AC post. One reading should be around .500 ohms as I recall and the other is an open circuit with no reading. To have one do what you are describing , one of the diodes from the AC to the B+ post is likely shorted so it will read .000 ohms or it will set off the beeper if there is one on the meter.
Diodes are one way valves much like a reed. They let AC thru in one direction, thus creating DC. Picture a reed either stuck wide open or one that will not open at all. Thats what happens when a diode goes bad. Either the AC signal goes back and forth thru it or nothing goes thru as in the case of the lost tach signal. If the tach is not working or the motor goes very rich all of a sudden its extremely likely that the rectifier is junk.

[Bill Rogers]

Good post Steve

A quick but less accurate check for a sorted diode is to take the same meter, put it on the AC scale, and measure the voltage with the engine running. Anything over a couple of tenths is a pretty good indicatation of a shorted diode.

Waterboy, whenever you talk to Bill Gohr I'd love to know what he suggests. Please keep us posted

[WaterBoy]

I got a meter, one direction displays nothing, the other direction displays, one side 397, the other is 395. Did I do it right?

Well, let's see, if I put the the red lead on the bottom of the rectifier and black on one post,535, other post beside it, 530, post that has postive by it,1078, sound right here?

Waterboy

[steve]

Yep. You did it right it sounds like. Looks like I was wrong about the rectifier guess. Try disconnecting the voltage regulator that sits behind the flywheel. Red wire and yellow wire go to the rectifier. Just leave the wires loose at the rectifier end and run the motor if you can't get a decent reading. Now check the Regulator to see if its open or grounded. Some guys don't even run the regulator at all. Check your air temp sender to be sure its plugged in and also check the resistance on that while you have the meter out. Its the 2 tan wires just under the starter, should read 5-10K ohms depending on temp. That 10% rich if its open. Last thing to check is the low side of the stator. Can't remember the specs on that one.

[Bill Gohr]

Did you pull the injectors and clean them? I had a 260 here a week or so ago did the same thing kinda and it was dirty injectors. As far as the rectifier goes thats a shot in the dark but I guess that wasnt it. Give me a call if you want give me the update. Just bring that P O S up here and we'll fix it. Can't be more than a 14 hr ride.

Did you tell me you changed that thing to Digital I don't remember, call me I'll be home all day today, ****TY weather no boating..........................

[BLIZZARD]

i like too know how i can clean my injectors

do i have too pull the screens out and blow same air true it ??


greetings menno

[WaterBoy]

Well, pulled the injectors tonight and all looked good, same spray pattern, none clogged or leaking, going to try the stator next. Will give update after the weekend.

Waterboy

[WaterBoy]

At least it'll take off, but, it's still not at it's best. It seems sluggish to me. If it idles alot, it seems to load up or something. After idling alot, real sluggish out of the hole, put it neutral run the rpms up and when it reaches idle put in gear and give it the gas, it's gone. Also, at about 7500 it seems to drop off. So, gonna try a fuel pump next. I got a 56lb reg. and the pump might be a 39 bosch. I don't think there is enough volume there. Putting in a fuel pressure gauge to see on that theory.

Also, the tach will not work under say 1100 rpms, it worked fine with my old carb motor.

One more thing, what's the thoughts on the voltage regulator on it, keep it or ditch it?

Any more suggestions?
I've changed: rectifier, ECU to PCU, stator, regulator, checked injectors.

Waterboy

[rob vaughn]

We all make mistakes, you don't have egg on your face....
It takes a heck of a man to admit he is wrong, dealer or not!!!!!

[steve]

Thanks man. Appreciate it. At least I didn't insist on putting 27 needle bearings on a rod or something really crazy!! Yikes.

Waterboy, Did you figure out the source of your woes yet?
Are you trying to run an A6 on a stock 260 by chance?
Screens pulled on the injectors ?
None of them weeped when you checked them right?
Did you check all the switch box, stator and ECU grounds?
Hope you get it figured out soon.

[WaterBoy]

Today, I tried an A-6 off a 2000 drag. It run alot better. Still tried to load up at idle though. Also wasn't easy to start.

Steve, injectors sprayed fine, none dripped or leaked.
Haven't checked switch boxes though
Screens didn't check, was in a hurry, (wife thing)
I got to change the rubber seals for the injectors though, they are leaking, fuel dripping off the injectors even on the hose.
Remember, I bought a PCU.
Going to try my old ECU next weekend maybe also.

Waterboy

[espen]

with the PCU you have all the power to change the fuel delivery at almost any rpm....take the cover off and adjust the idle delivery!
The steam wheel just adjusts the over all delivery like adjusting fuel pressure. (just my understanding of it...)
What kind of engine do you have? If its a tuned 260 you maybe have to tune in the fuel curve for a lot of the rpms?

[WaterBoy]

It's a stock 96 260 with an 1" spacer plate on it.

Waterboy

[stvhelm]

just read through your thread, I Know how you feel. I just went through something similar. It turned out to be a bad trigger for me. It almost sounds like your not getting spark 100%. Id try the trigger or switch boxes. triggers cheaper, do that first. how do the plugs look? are they burned evenly or some oily.

[KeithRichards]

Jason

Did you check the vacuum 90* on the air horn to see if it was clear. Had one stop up on me , played hell over something simple.

Keith

[WaterBoy]

Helmut, it was good talking with you. The A-6 run fine though. Loaded up a little during idle( in gear), but my buddy said it did with his motor also. I also talked with a guy from Texas that has a PCU for a stock 260. His made the same fluttering noise as mine, but not as bad. He adjusted the sensativity +3% and his runs great. Gonna try that. Palatka is this weekend, if all fails, I have an A-6 I can run. Or might just stay home, getting frustrated.

I also checked the nipple while on the phone with Tony, Guys don't get me wrong, Tony has been helpful as well as Jay Smith. Didn't want to leave that out.

This is gettin frustating, imagine this going on with your wife 5 months preg. also.

One weekend at a time,
Waterboy