| Author | Message | ||
     Stev0 |
I've just freshened up a '99 S3 that had some "electrical" problems before I got it. I found lots of other issues along the way and now have it to the stage of being ridden. It has started without any issues so far although I did notice it prefered no throttle to start. I've just tried to take it down to get it registered and it's decided it doesn't wish to play. Symptoms are. Started OK, and got about 4 blocks and slowed for intersection, it died and didn't want to start again. It would fire at no throttle but as soon as the throttle was opened it would die. I got it going by playing with the throttle and got it back home. Changed out the ECM with two others, still the same. Sidestand up or down, neutral, in gear, clutch in or out .. no difference. I'm going to start looking through the manual and going over the systems but has anyone had this SPECIFIC problem and did you find a solution. I'm not after a list of ideas as I'll be doing that anyway but if someone has had this problem before and knows the place to look it would be greatly appreciated telling me what to swap/change/fix... thanks Stevo | ||
| Stev0 |
replaced fuel filter, just in case that was the culprit.. It feels like a fuel shortage but not sure if it's fuel blockage or electrical signal, just charging up the battery and then I'll connect ECM spy and see if that tells me anything and then it's injector change.. | ||
| Natexlh1000 |
That sounds like a broken throttle shaft. The TPS is on the opposite side of the shaft from your cable. When mine popped, it acted just like that. The computer doesn't see the throttle move so there is one setting that is correct for the TPS. Playing with the throttle finds that correct spot where the computer squirts in the correct amount of fuel for the air getting in. | ||
| Stev0 |
Thanks, that's what I'm after.. I'll have a look at that. The throttle butterfly still moves as I noticed that when I changed the intake seals. Was thinking along the lines of blocked injectors or something in the electrical link of the throttle position through the ECM to the injectors. Broken shaft will do that..  | ||
| Harleyelf |
Might be the cam position sensor. | ||
| Stev0 |
OK, we're into the scariest thing a tech can hear "intermittent electrical fault" It looks like there's an issue in the wiring somewhere as I've just got a couple of trouble codes to come up and the TPS was giving an output and has now stopped. trouble codes.. 33, fuel pump short to ground or open 15, air intake sensor shorted to supply voltage or open. But those codes are coming and going,ie: not there all the time.. I'm thinking it might be time for the spare wiring loom. | ||
| 5liter |
When I had those codes on my 02 S3T it turned out to be a bad ETS. Replaced the ETS and it's been running fine. | ||
| Stev0 |
ETS ??? | ||
| 5liter |
Engine Temperature Sensor on the rear head. Mine was located in the chimney(center of the head). | ||
| Stev0 |
Thanks.. this one has the updated one in the centre. | ||
| Bluzm2 |
Sounds like an X1 I worked on a while back that wound up being the ETS. They make thing act VERY weird. Are you using ECM Spy? Check the ETS readings, if it doesn't change you found the problem. Let it sit and idle (if you can) and warm up. The reading should change. | ||
| Stev0 |
Can't get it to run/idle. now getting no throttle position signal and I've tried two other TPS's. Just about to try another ETS and see how we go with that.. It's something that's dissrupting the TPS signal to the ECM. I'll try and warm up the ETS manually and see if the reading changes. | ||
| Stev0 |
OK, ETS is behaving as it should.. dissconnected reads -10c .. Connected reads 20c .. Warm up rear head with heat gun and it slowly climbed to 27c.. Looks like that's not the culprit.. When I run it on the starter, not only am I getting no TPS reading but no RPM output either.. and the CPS has changed from green 0 to red 5 and back. It seemed to do that when I changed TPS's but I didn't check that each time. | ||
| Ratbuell |
Do you have a computer that will allow you to monitor TPS changes as you roll the throttle open and closed? It almost sounds to me like either a shorted sidestand switch, but sweep the throttle and see how the V readings react. | ||
| Stev0 |
Yeah, ECM Spy is giving me a real time view.. no TPS readings showing... it did to start with and then stopped. Changed out with two other TPS's and no difference... it changed the base voltage slightly between sensors but no reading of throttle position when moved.. also no RPM reading now. Change CPS, no difference It will fire with throttle fully closed but wont run when you try and open it.. I figured a sidestand switch issue would give me no spark as it would act like a kill switch and I've got spark. diagnostics on Tach, injectors and coil all come up good. It's looking like a broken wire somewhere in the loom as it also gave me a couple of fault codes early on showing open or short circuits. The previous owner asked me for advice a while ago and what we went through then seemed like a broken wire in the loom somewhere, which is why I bought another loom when he sold it to me. Was just hoping I could pinpoint it to a particular wire but without a breakout box that's difficult. | ||
| Oldog |
Steve just a thought the TPS, air temp and the crank position sensor are common to their power supply and ground, ( s12 /s13 ) the signals go to the ecm on pins 2(TP) 3(CP), and 10 (ET) of the ecm connector 11 (grey.. if the crank position is failing or there is a wiring issue this will cause a problem. The Fuel pump is on the black connector, pin 3, pin 1 GY grey? +12 ign pin 2 black - sys gnd pin 3 bn/y brown /yel fuel pump out pin 11 lt gn/gy - coil ground grey conn pin 1 +5v R/W tps / cp pin 7 - gnd 5v bk/ wht tps, cp, iat pin 10 signal iat ltgn/yel as others suggest there is probably a wiring problem either at the connector or under the tank some where. good luck . I hope that this helps..... | ||
| Stev0 |
Thanks Oldog... I'm learnin a few new tricks too. I'll measure power at those points and see what it gets me.. My gut is telling me there is a broken wire in the TPS circuit somewhere, no output to the TACH may be in the same circuit or likely part of the same issue. IAT sensor is reading correctly, so that would suggest it's not pin 7 Pin 1 comes into play tho if it's TPS and CPS. Time I sat down with a beer and the wiring diagram me thinks.. got me some data to look at now anyway. If it's in the loom then a loom change will fix it, I just wanted to pinpoint it so I learned something from the exercise. Which is why I didn't change the complete loom out while I was working on the rest of the bike. | ||
| Natexlh1000 |
I seem to recall that a few things on the system run on 5V that is supplied by the ECU. | ||
| Stev0 |
Yeah Nat, a lot of the sensors are 5v. They're usually a resisitor type and the ECM reads the change in voltage and the algoritm adjust output to suit. Looking at the wiring diagram it seems that there's more than one wire that's an issue, which means if I fix them there's a fair chance there's more ready to break. I have a nearly new loom here so I'll change it and start from scratch.. | ||
| Stev0 |
OK, still got same problem.. I'm thinking it's something really simple that is being missed or a parrameter that it outside what the ECM's algorithm is expecting and it's not outputting correctly. Here's a list of observations/data. Bike will fire and try to run on zero throttle but will not run when throttle is opened.. (will try increasing fuel output later to confirm 100% that it's a fuel issue) Spark good at all rpm's and throttle positions.. therefore not spark related.. No TPS or RPM readout on ECM spy. TPS did register on ECM spy when first plugged in but not after I had started playing with wiring.. However symptoms did not change. Tacho reads RPM, so RPM signal is being outputted from ECM Changed wiring loom for spare (no proof this one doesn't have the same issue as it was second hand but very good condition. low mileage. Changed Lambda sensor for brand new one have tried three different TPS's and all will not show change in position on ECM Spy but change voltage output when measured at the connector. ECM Spy registers different starting voltages for each different TPS tho, just doesn't register a change in position when moved. Tried 3 different ECM's ETS is reading correctly Sidestand switch removed no current trouble codes and no trouble codes in history related directly to TPS Instruments have been changed too. I'm going to get an electrician mate of mine who owns a few Buells to go over it with me as soon as he's available and hopefully between the two of us we can pinpoint it. He's also got some more sensors I can try swapping out as I've tried all the ones I have here. | ||
| Mr_grumpy |
One thing that lots of people forget on cars & bikes. The ground from the battery to the frame they always check, but the other link from frame to motor is often neglected & can cause all sorts of probs on a rubber mounted motor. | ||
| Firemanjim |
Has to be wiring issue, if ecm sees no change in TP it will not increase fuel so rolling throttle causes bike to die. | ||
| Two_seasons |
Stevo: What Firemanjim said  I had a similar problem with my 2000 X1 Lightning. Found a broken wire within the insulation. Visual would not have told me that! I found it by running my thumb and forefinger along each wire strand. Tedious but it works. | ||
| Stev0 |
The wiring has been completely changed out... replaced wiring loom, replaced TPS, new Lambda sensor, replaced CPS, different instrument cluster. I changed out the injectors and it runs, full throttle control and showing RPM readings on the Tacho... It is still, however, not showing any change in TPS position or RPM on ECM Spy. I'll test some more today as I connect everything else up and tidy the wiring but it's appearing like the injectors were the issue and either there was also a broken wire or wires in the origional loom which has somehow affected the readings that ECM Spy is getting or ECM Spy itself is not reading correctly on the laptop I'm using. It's looking like I've been chasing a problem that ECM Spy has been telling me I have that may not have been there at all... Don't you just love electronics ???? | ||
| Stev0 |
OK, tried a different laptop with a fresh install of ECM Spy to try and eliminate it as a an issue.. Same readings.. no TPS movement or RPM registers on ECM Spy. Everything else appears to be reading correctly. But the bike will run and idle OK... If you roll the throttle on gently, it will die. If you crack the throttle it will rev freely If you hold the throttle at a constant setting the motor hunts... as in if you hold it at 2500rpm it will rev up to 3500, give a feint cough and drop back to 2500, build back up to 3500 and repeat constantly and consitently.. .......... Just changed to another ETS.. same symptoms, no change. changed BAS.. slight change, not hunting as bad at constant throttle but dies when throttle closed fully. reset TPS again... no change.. So I have changed nearly everything I can think of at the moment but it still exhibiting the same symptoms that it did when it died a few days ago... which was died at closed throttle and could only get it to run by cracking throttle open and blipping it, not opening smoothly.. Time to go for a ride on a bike with a carby and then revisit this later and try and work out what hasn't been changed besides the fuel pump and yes that has heaps of pressure.. . (Message edited by stev0 on September 15, 2013) | ||
| Stev0 |
Just changed coil... no difference but it's been showing good spark anyway. Have been talking with the previous owner and he said it got progresively worse over a few weeks after he'd had major electrical problems, which is why I was looking at electrical to start with as I thought it had just started playing up suddenly.. Will try another set of injectors tomorrow and clean / test these other ones. The only things that haven't been replaced now is the fuel pump, reg/rec and switchblocks, everything else has been either replaced with new or exchanged with another secondhand part and it is still exhibiting the same symptoms. Gotta say I've never had a bike give me this much grief in 30 years of working on them... . | ||
| Oldog |
fuel pressure test, the idle value should be close or higher to spec spec 46-53 psi @ 2500-3000 rpm disconnect wiring loom for tps from ecm. check tps resistance over range of motion at ecm connector ecm spy is not regestering tps but all other sensors are working?, that points at wiring like FMJ says. have you swapped out the ecm? ( bad input pin for tps ) | ||
| Stev0 |
Two different wiring looms and 3 different ecm's ... symptoms same. All three TPS's I've tried show the correct voltage change and symptoms same. 2 different ETS, CPS, Lambda, BAS's, coils and injectors.. symptoms same although I thought I had a slight improvement with second set of injectors. Am going to make an assumption the TPS and RPM readings from ECM Spy are an issue with the computer interface as the tacho is reading RPM and look at fuel as an issue and explore that. So fuel pump pressure and injector clean/test tomorrow. | ||
| Mr_grumpy |
Inlet manifold leak? | ||
| Oldog |
All three TPS's I've tried show the correct voltage change and symptoms same. Where are they showing the voltage change? yeah if you see varying voltage in spy for the tps some thing else may be amiss. the hunting RPM could be related to an air leak as grumpy says, usually the engine wants to idle high, please keep us posted. } |
