Really Stumped with P0264 and P0267 Engine Codes

[BMANN06]

Hey All,

Any help is super appreciated! I have a sportster 4Tec (155), every time I start up the engine I get the following codes P0264 and P0267 which is injector short to ground or open. I only get one occurance of each code at startup (as seen on candoo scanner), engine runs just fine after that and no more occurances while running but get dash light and would like it to go away. Here is what I have done

-This engine is freshly rebuilt, maybe 45 minutes on it so far.
-I have 12ohms across each injector
-I have swapped all three injectors with known good

I've confirmed a good ground on PIN #1 of each injector. I'm a little confused by the seadoo manual about this statement "Check for 11.4 to 12.6 ohms between engine connector pin 3 and ECM connector pin 14. Where is pin 3 of engine connector?? If its the ECM connector I don't have any conductors in PINS 2,3,4

This boat is sold and the guy is picking it up Saturday if I can get this sorted that would be awesome!

Thanks a ton!

 

[griz400]

im looking around and reading on net, one article lists a fuse, starting to burn out ??? is there seperate fuses for these injectors ??? if so, check, and check for dirty or corroded connectors -- i replaced both injector connectors on my ski, looked sorta green, if they show fuses for injectors though, check, and could be like an ohm-resistance issue, all dirty connections, build resistance, resistance is due to sometimes corroded pins, wiring inside (this is why i never probe a wire) always just backprobe connectors where the wire is, not where the pins are, if people spread connector terminals, leads to intermittant problems -- ill keep lookin

 

[griz400]

i know you said you swapped some injectors around, you have a problem, with inj #2 and #3, so swap 1 to 3 and see if problem goes to cyl 1 , cause 1 is good now, if it is bad, then injector is

 

[BMANN06]

Hey Griz thanks very much for the help, I moved injectors around problem stays with that cylinder(s). I'm going to have start chasing wires now .. arrgghhh

 

[Dennis]

I'm confused BMANN. So you're saying that the engine has a miss when first started and then goes away? You scan the engine and those codes keep coming back?
The purple /? wires going to the injectors should be showing a constant 12 volts coming from the MPEM when engine is running. The ECU momentarily grounds the other injector wire in order to fire the injector. In other words: constant voltage and cycling ground.

 

[BMANN06]

Sorry for the confusing post, but basically as soon as you start the engine, It appears to miss and then runs just fine, the candoo programmer has a count field for occurances on a fault and only shows a count of 1 at startup. I was out in it today and after startup it runs very smoothy. I will test for 12V on the purple injector wires when running and post back.

Thanks for the help.

 

[BMANN06]

Just rethinking this ... set me straight if I'm off track. But If the control wire was shorted to ground that would blow a fuse wouldn't it? So it would be the other wire, thats being switched to ground then off? This would be the MPEM doing the switching? So if I don't have an actual cable fault where this wire is cracked somewhere and shorting to ground then I have an MPEM problem? Am I following this or did i get totally lost? With engine off, and battery off, should the switched ground wire to the injector have a path to ground or not?

Sorry for the 10K questions.

 

[griz400]

the purple wires, from the mpem , should have 12v, then the mpem turns the ground on and off, question to you now, cause i dont have an acess to manual, is all 3 purple wires, spliced together somewhere, or are there 3 seperate purple, and 3 seperate ground wires, -- and when i say ground wires, they are only grounded by mpem on, then, off, on, then, off -- to pulse injector -- if all 3 purple wires, have a factory splice, then this is where i beleive your problem is, cause, inj 1 is good, if all 3 were bad, i would say mpem problem

 

[griz400]

what manufacturers do is, they have a circuit, yours being and injector 12 volt supply circuit, then they start off mpem with 1 wire, (to save money) -- then get down near engine area, then they make a splice -- to 3 wires, 1 going to each of your injectors -- this supplies all with 12 volts, --- then they have to run 3 seperate wires, from mpem to fire them in time with your piston, we find factory splices bad all the time, if this is the case, then just cut it all out, solder and heat shrink wiring again

 

[BMANN06]

This is the wiring diagram I've been using so far. It is the same as my boat, with the exception my MPEM is different. But cable colours are still the same.

 

[Dennis]

Ok, the MPEM is supplying the 12 volts.The ECM is supplying the momentary ground (not shown in the above wiring diagram). You are correct that if he MPEM wire/s were shorted it would cause a fuse to blow but not if it is a "open wire" situation. I don't know if the switched wire is grounded when engine is off.
Sorry, the ECM is shown.

 

[griz400]

intresting, 12 volts to injectors and coils is supplied from mpem and pulsed by signals from ecu, seperate module, i would look for the problem, not so much at the mpem, i see a trouble spot, looks like, in a connector between the mpem and injectors, (on your diagram here, its a 4 wire connector, with the 3 purple wires in it, the cavities number 2 and 3 in that connector, purple/orange and purple/green probably all corroded or something, maybe a spread terminal or something, (maybe will look green in color) -- its the connector under the fuel pump in the picture -- intresting how its wired, i seen others complain about this earlier when i googled problem, could be your gettin some interference (resistance ) from coils, they supply coils from these wires also, so this connector i'm talkin about, must be clean, not corroded

 

[BMANN06]

Thanks guys ... ALOT! I have a good understanding of how the circuit works now. I think I'll shut it down for tonight its around 45F out there now that sun has gone down. I'll check the 12V rail across the 2 problematic injectors in the morning. Regarding the switching of the ground. I should be able to put my multimeter lead on ground then other lead on "Switched Grounded" wire of injector and see continuity going on and off between ground when engine running. This make sense? I'm hoping I can get this sorted...

 

[Dennis]

It happens so fast that I don't think you can get a switching type reading that way. I'm with Grizz on the corroded connections.
The ECM ground wires are grounded at the front of the engine by the motor mount. Check those connections also. :cheers:

 

[BMANN06]

Hi Dennis, your right what I was thinking and typing were two totally different things. I've got an ocilliscope at the shop and thats where I was going there. I will get back to troubleshooting after work today and will check out the ground side. Quick question(s) though, I've got a 4tec gti (its sold too but still have it for another couple weeks). If it turns out to be the ECU (switching problem), can I borrow the ecu from the GTI? Or are the units flashed for skis only? Or will the ecu relearn itself when plugged into a different vessel? I'm thinking that you and griz are right though and this is some kinda grounding problem, as this just happens at startup. All three injectors are fine after a few seconds of running. It would be very obvious if this thing was only running on one cylinder and that certainly isn't the case.

You guys have no idea how much I appreciate your help! Thanks Again!

 

[Dennis]

If the ECU is the same part No. as the boat then I would try it it. You will also need the GTI lanyard as it is matched to the ECU. I would NOT do the switch if the part no. are not the same. You might burn up a ECU. A ECU will not relearn itself. It is what it is.

I've been thinking about this situation. Make sure you are getting a FULL 12 volts from the MPEM to the injectors. I can see where a lesser voltage would cause this problem on start up. A lesser voltage would more than likely mean, as Grizz has pointed out, a poor connection in the wiring harness or even corroded terminals on the fuses, etc.

 

[BMANN06]

I think its starting to look like ECU, i've pulled the harness apart, no sign of corrosion. I have removed grounds sanded the terminals ... cleaned them up still same problem. I do have 12.56V at injector while running. I check that the switched grounded wire to the injector does not have a short to ground. Anything else I should be looking for prior to shelling out $800 for an ecu?

 

[BMANN06]

Well just made up a noid light and problem definately isn't the ECU, LED blinks consistently while engine running ...

Now lost! LoL

 

[Dennis]

I would disconnect 1 of the coils, start the engine and then check and see if the scanner came up with a fault code for that. I'm trying to determine if the ECU knows what it's talking about.

 

[BMANN06]

Hey Guys just an update:

I've swapped the "A" harness with a known good (borrorwed from GTI), there was a difference in the two harness, some sensors moved around so I got codes for them (expected), but still got the engine to run. I saw the P0261/64/67 codes (all three injectors this time). So put the old harness back on, cleared the codes that came up from missing sensors, and got the same result P0261, P0264, P0267. I got thinking about what Dennis said about the voltage drop when the starter turns (makes sense) thinking that the starter was pulling high, so swapped the starter ... same result.

I think I just order up a replacement ECU.

 

[BMANN06]

**solved**

Update guys, just got back from the guys house that bought the sportster, the new ECU fixed it. What burns my ass is I don't think there is anything wrong with the driver. Prolly just a firmware update .... :rant:

 

[ocod]

Update guys, just got back from the guys house that bought the sportster, the new ECU fixed it. What burns my ass is I don't think there is anything wrong with the driver. Prolly just a firmware update .... :rant:

Glad you got New boat fixed.....

 

[Dennis]

It may have been a pain in the ass but look at all the knowledge you gained!!!! :rofl: I hate when people say that to me cause they weren't the one who had to go thru it.

 

[BMANN06]

Yah that def. was a PITA! ... Thanks again for all the help!

:cheers: