Tom M Posted June 6, 2009 Share Posted June 6, 2009 Over the last week or so I've noticed that sometimes my fuel pump wasn't priming when I turned on the key. The starter would turn over but the bike wouldn't start due to no fuel pressure. Sometimes it would prime 10 seconds after turning on the key, other times I'd try different combinations of cycling the kill switch, wiggling the bars, and shifting in and out of neutral. I also swapped relays around and swapped in a new fuel pump fuse even though the old one ohmed out good. Eventually I'd hear the pump fire the bike would start. It would be OK for a few days then intermittently act up again. There was no one thing that I could do to consistently get the pump to fire when it was failing to prime. Last night I pulled the fairing & tank and checked the clutch switch wiring and sidestand switch wiring. They both ohmed out good and had good connections to the wiring harness. I couldn't think of anything else to check so I put it back together and it fired right up. It fired right up again today when I rode it to my daughter's soccer game, but acted up again when I went to leave. When I got home and shut it down the pump wouldn't prime again when I turned the key back on, regardless of what I did with the bars, shifter, or clutch. Swapping relays didn't help and all of the fuses are good. I pulled the tank and checked all the connections again, and this time I checked the fuel pump connections too. Everything is solid. I put a meter on the pump connections and verified that it's not getting power with the key on so the pump is not the problem. I disconnected the clutch switch and put a jumper on the harness, no change. I plugged a spare ECU in, no change. Battery shows 12.5 volts. I'm stumped. Does anyone have any suggestions on what I should do next? My only guess is start looking for chafed wires. Any help would be greatly appreciated! Link to comment Share on other sites More sharing options...
fotoguzzi Posted June 7, 2009 Share Posted June 7, 2009 sounds far out but try cleaning the ignition switch. you've tried everything else! Link to comment Share on other sites More sharing options...
raz Posted June 7, 2009 Share Posted June 7, 2009 I think Foto's suggestion is a good one. You can easily jump the switch (or measure it) if you locate its connector block. Link to comment Share on other sites More sharing options...
Tom M Posted June 8, 2009 Author Share Posted June 8, 2009 I found the problem, it's the ECU. I rode the bike for 40 minutes to get it good and warm, shut it down for 5 minutes then tried to restart but again the fuel pump wouldn't prime. While in this "no prime" mode I found that with the key on I could push on the ECU connector and trigger the fuel pump relay, every time, with or without the PCIII in the loop. Initially I thought it was a broken wire in the PCIII harness but when I took it out of the loop and plugged the main harness connector into the ECU I realized that it was pressure on the connector, not the wires, that would trigger the fuel pump. I did this at least 10 times and I'm convinced there's a broken etch or solder joint in the ECU. I don't know why I didn't pick up on this the first time I swapped ECU's. My only guess is the the alligator clip jumper wire that I used to ground my extra ECU wasn't adequate. I was using the stock ECU with a downloaded map that I've tweaked over the last 2 years to get the bike to run really well. My spare ECU is the Ti version so I'll have to get a new map if I'm going to use it. Do any of you guys have a spare pre-03 ECU that you'd like to sell? Link to comment Share on other sites More sharing options...
fotoguzzi Posted June 8, 2009 Share Posted June 8, 2009 how do you know its the CPU and not the plug? Link to comment Share on other sites More sharing options...
Tom M Posted June 8, 2009 Author Share Posted June 8, 2009 how do you know its the CPU and not the plug? I got the same results with the plug on the PCIII harness and the plug on the stock harness. That indicates to me that it's the male receptacle on the ECU that's the problem, not either of the plugs. Link to comment Share on other sites More sharing options...
fotoguzzi Posted June 9, 2009 Share Posted June 9, 2009 I got the same results with the plug on the PCIII harness and the plug on the stock harness. That indicates to me that it's the male receptacle on the ECU that's the problem, not either of the plugs. good , just testing! could a tight zip tie do the fix? Link to comment Share on other sites More sharing options...
Tom M Posted June 9, 2009 Author Share Posted June 9, 2009 good , just testing! could a tight zip tie do the fix? That might work for a little while but I wouldn't trust it for long. It would be just my luck to have it fail 150 miles from home. In the rain. The bike wouldn't start after I gassed it up the other night. I popped the seat off and pushed on the connector, heard the relay trip and the fuel pump prime, put the seat back on and it fired right up. I rode home and parked it until I got around to installing my spare ECU last night. I think it's kind of strange that once the bike is running there's no problem. Anyway, last night I installed my "Ti Race" ECU and a PCIII map that I ran with it a few years ago and it's running good. I think the map could use some adjustments, but it will do for now. I removed the cover from the faulty ECU and took out the PC board. I'll check it under a microscope at work to see if I can spot any broken solder joints. If the problem is a broken etch inside the board I doubt I can fix that without a schematic. It's nice to not have to worry if the bike is going to start every time I hop on Link to comment Share on other sites More sharing options...
mznyc Posted June 9, 2009 Share Posted June 9, 2009 Hi Tom, Nice find. With no PC3 I found that the bike ran better with stock ECU than with Ti's ECU.I'm sure a well tuned PC3 with TiECU set up would be optimum,but in stock trim even with fiddling with TPS couldn't get it quite right. Link to comment Share on other sites More sharing options...
Tom M Posted June 9, 2009 Author Share Posted June 9, 2009 I found the broken etch and repaired the ECU. Here are the pictures in case anyone else ever runs into this problem. Top side of ECU board: Back side with screwdriver pointing at connector pin with broken etch: Repaired: Link to comment Share on other sites More sharing options...
luhbo Posted June 9, 2009 Share Posted June 9, 2009 Tom, what is this red and silicone secured thingy? Haven't seen it before. Hubert Link to comment Share on other sites More sharing options...
Tom M Posted June 9, 2009 Author Share Posted June 9, 2009 Hi Tom,Nice find. With no PC3 I found that the bike ran better with stock ECU than with Ti's ECU.I'm sure a well tuned PC3 with TiECU set up would be optimum,but in stock trim even with fiddling with TPS couldn't get it quite right. On my bike the stock ECU with a good PC3 program pulls strong from 2k rpm to redline, but my butt tells me that the Ti ECU pulls harder above 4k rpm. I'm going to run with the Ti ECU for a while and see if I can either tweak the map to get it to run better, or try someone else's map if they will share it with me. The single best thing that I've done to my bike was to set the TPS using the Micha method. I believe the Ti map that I'm using now is off because the previous owner had the map created without getting the TPS set correctly first. I don't know why but my bike runs like crap if the TPS is set to 150mV baseline (with the linkage disconnected). Link to comment Share on other sites More sharing options...
Tom M Posted June 9, 2009 Author Share Posted June 9, 2009 Tom, what is this red and silicone secured thingy? Haven't seen it before. Hubert It's a radial lead component, probably a capacitor, that's bent over onto the board and gooped into place. That's the same goop that they used to attach the cover to the ECU case. Link to comment Share on other sites More sharing options...
Guest ratchethack Posted June 9, 2009 Share Posted June 9, 2009 I don't know why but my bike runs like crap if the TPS is set to 150mV baseline (with the linkage disconnected). Tom, just curious. After "indexing" to 150 mV baseline, what TPS reading does this give you at idle with TBs linked, and at what RPM is your idle? Nice "find and fix" work on that broken etch on the PC board, BTW. Was the break a result of something physically contacting the board, and how did you find it?? Link to comment Share on other sites More sharing options...
Tom M Posted June 9, 2009 Author Share Posted June 9, 2009 FWIW I put a piece of clay on top of the harness connector where it plugs in to the ECU, then I put the seat on and bounced on it a few times. The clay showed VERY little clearance between the bottom of the seat and the harness connector. I'm guessing that my seat has contacted the connector a few times and that's what caused the etch to pop at that connector pin. Maybe it's time to lose some weight Link to comment Share on other sites More sharing options...
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