Ecu Question For Jay Smith Or Anyone In The Know

[stroker]

I HAVE WHAT IM TOLD TO BE AN A48 BOX, I POSTED A QUESTION TO YOU ABOUT AN OVER RICH CONDITION THAT REQUIRES TURNING OFF THE FUEL PUMP TO GET IT GOING,WELL I CHECKED THE INJECTORS ,PULLED THE RAIL WITH UM ATTACHED TURNED ON PUMP NONE LEAK,ON THE BACK OF THE ECU BOX AT TOP,IS WHAT APPEARS TO BE A MICRO SWITCH,BLACK IN COLOR AND IS PROTRUDING THRU BACK OF ECU HOUSING,SWITCH APPEARS TO BE IN BAD SHAPE,WHAT IS IT AND WHATS IT DO? IT HAS A BLUE AND GREEN WIRE ATTACHED THAT LOOKS LIKE IT WAS THERE FROM FACTORY,YET THE PEOPLE IVE DELT WITH HAVE NEVER SEEN THIS SWITCH BEFORE .THE TOGGLE ON IT IS FRIED BUT HAS APPEARED LIKE THAT FOR A WHILE,AS IN SINCE I GOT THE MTR,ALONG WITH TROUBLE OF STARTING, IN THE UPPER RPM THE MTR IS FLAT,AND PEOPLE WATCHING ME TRY TO BLOW IT UP SAY ITS FOUR STROKING OR RUNNING REAL RICH BY LISTENING TO IT.OK HERE WHERE IM GONNA SOUND REAL STUPID I AM SURE.THE FUEL PUMP I AM RUNNING IS ON SWICH TO 12V ON DASH.THE ORIGINAL ONE WAS ON A WIRE IN THE AREA OF THE STARTER SOLENOID WICH WAS STILL HOOKED UP AND WAS SUPPLING POWER WHEN SWITCH WAS ON TO ECU FUEL PUMP WIRES ,COULD THIS HAVE CAUSED THE ECU TO SEND SIGNALS OF WHAT THE MERC BOOK REFERS TO AS TRIPLING THE PULSE WIDTHS.I GUESS WHAT IM SAYIN IS,IS THROWING VOLTAGE AT THE ECU WITH NO FUEL PUMP WIRED BEHIND IT A PROBLEM,OR COULD IT HAVE BEEN.AND BY DISSCONNECTINGT THESE WIRES COULD THER BE FAILURE..

[Jay Smith]

Eveytime I write you a long post this #$%@^ computer kick me off , please cll me @ 1 281 576 5088 . CST I will be waiting on your call.......

Jay @ JSRE

[us1]

There are two yellow with a red strip wires on the starter solenoid. One runs into the wiring harness going up in to the boat and the other run into the EFI harness going to the ECU. Disconnect the yellow and red wire going to the ECU. This is the choke wire. Ever time you go to start the motor when hot it is choking it and flooding it. Turing off the pump is defeating the choke. If this works for you just put a push button on the dash connecting this wire to 12 volts only when you need it.

[stroker]

TALKED TO MR SMITH,PRETTY WELL NARROWED IT DOWN TO ECU PROBLEM. THANKS AGAIN,,,BUT ID STILL LIKE TO KNOW WHAT THE SWITCH ONN BACK OF ECU BOX IS FOR LOOKS LIKE SIME SORT OF RESET SWITCH.

[NPW]

Send your ECU to Rapair for the test.. call Shaun 1st he can tell you anything you want to know about the electronics..that A48 box when right has a serious lean spot in the mid-range,it was made for the race circuit..the A40 is a much better ECU for lake cruising..like John said, at lest remove that 12 volt feed wire,if it's hot all the time the injectors on time is tripled,it should be either grounded or hooked to push-switch on ing. switch..:(

[us1]

I got my boxes back.:cool:

[NPW]

John, let me know what you think when you run them...:D

[us1]

I have run them before, they run pretty good.

[MERCMAN]

STROKER , THERE SHOULDNT BE ANY SWITCH ON THE BACK OF YOUR BOX , EMAIL ME @ [email protected] FOR MORE INFO! -- YES THERE IS AN AIR TEMP SENSOR ON THE BACK , BUT IT DOESNT LOOK LIKE A SWITCH. IT WILL BE A BLACK PLASTIC TIP STICKING OUT THE BACK OR WHAT APPEARS TO BE A SHAFT WHOLE WOTH NO SHAFT , THAT IS THE NEWER FLUSH TYPE.

[RichS]

Stroker, I think the "toggle switch" you're talk'in about on the back of you're a48 is the intake air temperature sensor. I have a box that is in about the same condition as your's. The stupid sensor is sticking out the back of the box and if the box was ever taken off and mishandled the sensor gets broken. The later boxes have a sensor that is recessed so it isn't exposed to damage. Now I just gotta find ona dem.

[Bill Gohr]

That black thing on the back of the box is the old style air temp sensor. I have the new style external ones in stock. John is probably right if this was an older motor with an analog. the enrichener wire is probably hooked to the starter solenoid. Disconnect the yellow red from the ECU harness to the starter solenoid and connect it to the yellow black. Then it will enrichen only when you push the key in. If you think you still have an ECU problem I can check it for you or I can replace it with a 849849 (A6) any map stlye for $600 including UPS.

[Steve Pope]

Have you any buddies that will loan you an ECU to try(a known good one that is)If problem goes, send your ECU to an expert repair shop for diagnosis and repair. If problem still apparent then start from scratch and go through all electrical systems from key and kill switch to engine.Start at the simple things first and keep it simple. 95% of all faults are simple and inexpensive!!!!!!1

[stroker]

dissconnected yellow/red to solenoid.boat wouldnt crank,reconnected and dissconnected yellow/red to yellow black,no apparent change,put ohm meter between yell/red-yell/black nothing.rehooked as i found it,while it was idling on hose pushed key in to choke and it instantly loaded up and died.when mtr is off but key on when you push choke you here it click,my guess something internal on ecu. found new problem looked up in exhaust housing outlet ,there is two metal baffles that are just rattling around is this the tuner or something to direct exhaust gases on around corner,its an offshore exhaust.in response to borrowing ecu,,sounds good but hate to hook someone elses pricey electronics to my junk.when it runs good again it'll be the greatest mtr ever built,isnt that how it usually goes.

[Steve Pope]

lift the powerhead and put that exhaust back the way it left the factory. A simple fault not expensive to fix

[Bill Gohr]

Motor originally? We go back to a long post not too long ago. Was this an analog motor originally? If so we have to change the nipple in the air horn and modify the wiring harness. That will clean-up the bottom end. As far as the flat top end I think you found it. If the tuner is falling out, or damaged, the motor will not be making the HP it should be at top end and therefore act rich. What this will do at idle I can't really say. Any questions give a call. 847-356-3245 847-274-9378

[stroker]

AS A 2.5 EFI,THE STORY WAS THAT IT STARTED LIFE AS 2.5 CARB MTR WAS CONVERTED TO EFI.EVIDENTLY THE FRONT HALF WAS A MISMATCH,KEPT KICKEN OUT THE TOP BEARING,ANY WAY THE EFI BOX IN MY HAND HAS THE #11350A ON A STICKER ON THE BACK,THAT IS WHAT THE MTR WAS SUPPLIED WITH.THE MTR HAS HAD THE LOADING UP PROBLEM(STARTING SINCE I RECIEVED IT) THE TOP END IS SOMETHING THAT HAS HAPPENED SINCE. ITS GOT 39 PSI SET UP,AND AFTER CHECKING REG. ITS GETTING 39PSI.

[DaveR]

What kind of TPI does the motor have, vacuum or mech.?

[stroker]

must be vacuum,cus thre isnt a mechanical one on throttle linkage.

[DaveR]

This may not help much, but the ECU on my 2.4 was changed from an analog A7 to an analog A13, and the A13 was a later model made to run with a vacuum TPI (I had mech.). I had to cross two of the tree wires from the TPI to make it run. The way it was, the ECU was being told to go full rich at all times. Even Rapair couldn't tell me whether I should cross the wires or not. I had to cross the pins and see if it ran better. Maybe someone can tell you if your ECU was designed to work with the vacuum or mechanical TPI.

Hope this doesn't send you off on bum track.

[us1]

It has another number after the A, like A48, A6 or something like that. If you can find that number that will tell all.

[Bill Gohr]

He needed a little help on his wiring and a lot of assistance with his center section. He was a little confusing on his original post. His motor starts ok then goes rich, also, it starts and runs OK on the hose but not in the water, what's wrong?

[us1]

Hey Bill, I was wondering if it has a TPI like Dave said. That could be the problem. I assumed it was a digital at first. The first thing to do though is put the tuner back on.

[stroker]

i was alsmost dissapointed to see it,hoping we had a quick fix,gonna get this broke sheet metal tuner out and ill call ya order up what i need,ill fix what i know is broke try it again and we'll go from there. thanks

[us1]

If you are running an analog box with out a TPI that is your problem unless it is the one box that doesn’t require one. It would sure help if you could just tell us what the A number is on the box.

[DaveR]

John, I think he's saying he has a TPI. I that's the orange and blue wires he was talking about. Sounds like they are crossed already like I had to do. I was told not to jump them, but to remove the pins at the connector and switch locations. Don't do anything that could change the resistance.

[us1]

It sounded to my like he was talking about the jumper plug that replaces the TPI when you change over to digital.

[DaveR]

You're probably right. I might be reading something into it. It would help to have the whole info, as you say - including the ECU #

[Bill Gohr]

When I got him on the phone we figured out he may have a couple of small problems on the powerhead like the wiring and the correct vacuum connection. When he told me it ran ok on the hose and not in the water I figured he had an exhaust problem. His tuner had broken or fallen out. We'll get him fixed up now, no wonder it wouldn't run on top end.

[us1]

No top end ,thats for sure;)