Author Topic: Surging Brick (Read 37294 times)

mophead · « **on:** March 26, 2018, 11:59:09 AM »

Have an issue that has occurred lately. Had a battery that I replaced couple of weeks ago. Got out one day and bike would not start. Started fine at home but not at a stop. Pushed and popped clutch and made it home fine. Bought new battery next day and installed. Took bike out four days later and bike was running well except thought I felt a little surge at steady throttle. It started getting worse so I u turned back home. Figured it was fuel filter. Changed it our for new and still surges. Had an extra fuel pump that came with the bike so changed that and still surges.

Bike idles fine but if you get on it hard you can feel the surge. Surge mainly occurs at steady throttle. If on or off I don't feel it.

If I let it sit overnight it is now hard to start like it is getting no fuel. Once I coax it to start it starts fine on first bump after that. Replaced spark plugs and that did not help. Old one looked fine except they were some double electrode Bosch plugs. I'm leaning toward the fuel pressure regulator being suspect or perhaps a line going to or from it.

Have searched several threads and not really seen anything about surging and a fix. I did do the propane test around the rubber at injectors and intake rubber bushings and did not see any increase in engine speed.

Had the bike out for several runs of 200 or more miles before changing the battery and it ran just fine. No surge or rough running at all. Just ran like a good K bike should.

Fuel pressure regulator and new battery doesn't make much sense but perhaps the collective wisdom here has had this pop up before. Any suggestions appreciated.

Chaos · « **Reply #1 on:** March 26, 2018, 12:33:26 PM »

maybe not the same thing, I had some cutting out and stumbling issues that turned out to be water settled in the bottom of the tank, a bottle or 2 of HEET and some WOT antics took care of it.

mophead · « **Reply #2 on:** March 26, 2018, 01:04:54 PM »

Its not water as I had run it down to almost empty on last ride before this started. Filled with fresh gas and running Techron in this tank just to clean combustion chambers. Maybe the surging will dispense the Techron better. :dunno2:

The Mighty Gryphon · « **Reply #3 on:** March 26, 2018, 01:21:47 PM »

Double check the big connector on the Jetronic box and the connector for the fuel tank. I'm pretty sure you had to disconnect and reconnect them when you did the battery. You won't be the first to have put one of them together loosely.

How is your throttle position switch set? It's a long shot, but if it's set to trip at the throttle setting for cruising speed it could be shutting off the fuel momentarily at engine speeds above 3000rpm.

The Mighty Gryphon · « **Reply #4 on:** March 26, 2018, 04:41:34 PM »

Jetronic and TPS?! What was I thinking??? Motronic. Still, check the connectors...

Martin · « **Reply #5 on:** March 26, 2018, 05:06:25 PM »

Check your FPR I had surging with a partially blocked return line. It was kinking where it goes back into the tank.
Regards Martin.

bizzaro · « **Reply #6 on:** March 27, 2018, 09:13:56 PM »

Quote from: mophead on March 26, 2018, 01:04:54 PM

Its not water as I had run it down to almost empty on last ride before this started. :dunno2:

So when you say surge, do you actually mean cutting out or stumbling? That's what I thought. And this happened right after running the tank almost dry? Maybe you have sucked any possible crap that was in the tank into your lines? I would start by purging your fuel lines as much as you can by disassembling them at all connections and try and run some fuel through them. IE: At the fuel rail, disconnect the hose, stick in a bucket and turn on the key to to turn on the fuel pump and run some gas through it. Then move on to the fuel rail and disconnect the line to the FPR. Where you can, hook it up in reverse to back flow. Do this at all your connections right on up the line. Remember the fuel will/may be under pressure when you are disconnecting them, make sure you have eye protection and something to to catch spray(rag), and (bucket) to catch the fuel. Just by draining and back draining you may get lucky and clear them out. I think you got some crap in there. And it is lodged somewhere in your fuel system and causing your "stumbling"! Just a hunch?.

mophead · « **Reply #7 on:** March 31, 2018, 01:50:26 PM »

Been f-----g with this thing all week and still no fix. After sitting overnight it does not want to start. When I finally get it started and running then take it out for a test run I still get the surging and loping at speed. The more rpm i give it just starves it more. Get in up around 6000 rpm in third and its almost like a bucking horse. I've done all the troubleshooting things one at a time and then a test ride.
I have taken all the fuel lines off and flushed them. Put a pressure gauge on the fuel rail where it goes back to the tank and get a steady 38 psi when it is running.
Have cleaned the Motronic plug three different times. Cleaned the four wire plug twice. Replaced spark plugs and air filter. Replaced the fuel pump and the fuel filter.

I can't believe changing a battery and getting low fuel light can destroy what was a sweet running bike. At this moment in time I would be up for taking it outside my shop and set the sumbitch on fire and watch it burn. Count it up to just one more money mistake made in my life.

Sorry for the rant and appreciate all the help given but this thing is really pissing me off.

The Mighty Gryphon · « **Reply #8 on:** March 31, 2018, 02:27:21 PM »

I can sort of feel your pain. I spent most of the summer a few years ago trying to get the rear master cylinder on my K75RT to stop leaking.

Knowing now that you have a Motronic system on your bike I wonder if you have done any checks for fault codes that the Motronic may have stored. Have you seen this article:

http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/Motronic%20Fault%20Codes.pdf

The procedure for setting the throttle position sensor(TPS) is pretty nice. It really makes setting it easy.

mophead · « **Reply #9 on:** April 06, 2018, 08:58:20 PM »

OK here come the dumb questions.

When I hook up the connections to test the Motronic all I get is 3333 fan test. It doesn't give any other codes. Turned off the ignition and restart the test and get 3333 every time.

When testing for the TPS I assume it has to be connected. How do you connect to pin 1 and 4 if the TPS plug is connected to the TPS? I unhooked the connector plug and turned ignition on, connect voltmeter to pin 1 and 4 and get .002 on the voltmeter but that takes the TPS out of the loop. Do you have to take the rubber boot off the connector to check pin 1 and 4 while it is hooked up to the TPS?

The Mighty Gryphon · « **Reply #10 on:** April 06, 2018, 10:40:07 PM »

Throttle Position Sensor (TPS) Test distilled from the link I posted above:

To test the TPS: With the Ignition OFF, Ground Pin #3 on the test connector. Turn on the ignition. Open and close the throttle. You should be able to watch the temperature warning lamp on the tachometer blink ON at idle and OFF just above idle.

To adjust the TPS: With the throttle closed, loosen the TPS screws and adjust it so the lamp is just coming on. Of course, you are going to do this with pin #3 connected to ground and the ignition ON.

There is no need to connect to the TPS.

bizzaro · « **Reply #11 on:** April 07, 2018, 07:06:17 AM »

To set my TPS on my 94 16 valve motronic LT, I had to slip a couple o thin wires into the pin 1 and 4 of the TPS and connect it. Then read it with a voltmeter. I used some thin wire off a small coil winding. You just slip um in there on pin 1 + 4 close up your TPS connection, connect your voltmeter and turn on the key. You should get a reading of .375. And the adjustment is really touchy to get right.

http://www.motobrick.com/index.php?topic=1521.0

Redundant post! Oh well! That'll happen!

mophead · « **Reply #12 on:** April 07, 2018, 01:31:47 PM »

Tested TPS for voltage. It was out of range at 0.480. Readjusted to 0.375. Thanks bizzaro for the small wire tip. It works.

TPS light on at idle, goes off just off idle just like the test says it should.

As I read this the Motronic test should have shown 1215 TPS out of range. It did not. Every time I hook the number one pin on the connector all I get is 3333 fan test. Turn it off, ignition back on, ground for 5 seconds, then 3333 code with fan coming on and off during the test. I get nothing but 3333 when testing Motronic. Have not got 4444 or any other code at any time.

Is there a different way to pull Motronic codes that I am doing wrong? Did I fry the thing changing the battery?

Bike still will not start. Plugs are getting gas. They're wet.

bizzaro · « **Reply #13 on:** April 07, 2018, 02:30:01 PM »

Are you getting spark? Pull your plugs, at least one, make sure they are grounded and turn the engine over. Hope for a minor light show.

mophead · « **Reply #14 on:** April 07, 2018, 03:15:34 PM »

Earlier could not get bike to start. Adjusted TPS to 0.375 volts measuring from pin 1 to pin 4 on TPS and still would not start. Walked away for about an hour and then went back and pulled #1 plug to see if spark and bike started right up with plug out. Plenty good spark visually on removed plug. Now put plug back in and start it up. Bike would idle fine once started before TPS adjustment. Now it won't stay running at idle. Just dies. Give it some gas while running and it stumbles down and dies.
Checking TPS via voltmeter and number 1 pin on test connector I get 2.86 volts at idle. Test says it should be zero volts. Off idle I get 12.25 volts which as I read it should be fine.

Hook up number one pin to check motronic codes all I get is 3333 fan test with fan on and off intermittently. Is that the default for checking motronic codes? Never have got anything but 3333 fan test. Turn off ignition to clear to next fault and returns to 3333 each time.

That doesn't seem right.

bizzaro · « **Reply #15 on:** April 07, 2018, 05:22:52 PM »

I have a feeling your not doing the sequence right for checking fault codes. Last year when I was checking my codes I accidentally put it in fan test mode. It is very similar. You need to be sure you are hooked up properly and follow the process verbatim. See Laitch's link below!

And pretty sure you need analog VM. I assume you have the directions handy? Notice you have to ground it a second time, then remove the 2nd ground after about 5 seconds? But really I don't think the codes are gonna help ya. But who knows. Have you tried to balance the throttle bodies? Also ignition switches are suspect in these instances. It is easy to buy pass the ignition to check it? :dunno

Laitch · « **Reply #16 on:** April 07, 2018, 05:32:31 PM »

Quote from: mophead on April 07, 2018, 03:15:34 PM

Turn off ignition to clear to next fault and returns to 3333 each time.
That doesn't seem right.

Here, under the heading Motronic Codes, Anton Largiader mentions pulling fuse#5 for a few seconds to clear the fault codes

bizzaro · « **Reply #17 on:** April 07, 2018, 05:42:18 PM »

:2thumbup: Laitch. How do you remember all these links?? :eek: Your a freakin walk'n encyclopedia! :2thumbup:

johnny · « **Reply #18 on:** April 07, 2018, 07:46:58 PM »

greetings...

everybody knows about fuse 5... its assumed you already pulled fuse 5... like its assumed you turned the key on and pressed the start button before you say it wont start... plus you are running the fan test over and over again... sounds to me its a mixture problem... too rich perhaps...

autumrideafterweedcookies.jpg (62.02 kB . 768x556 - viewed 820 times)

j o

mophead · « **Reply #19 on:** April 08, 2018, 02:20:27 PM »

Pulled fuse 5 last night and let it set for 30 minutes. Went out this morning and bike would not start. Went back to it 30 minutes later and it started up first bump of the starter. Seems to idle fine now. Put fresh gas and more Techron and took it for a ride. 20 miles into the wind and it ran fine with no surging at steady throttle.

Turned off onto a side road and it started surging stumbling again. Went about 50 miles total and surging all the way home. When I finally get it started it smells like its running rich. Going to let it cool down and pull plugs to see what they look like.

I did try the motronic test after pulling fuse 5 last night and it immediately goes to fan test 3333.

bizzaro · « **Reply #20 on:** April 08, 2018, 06:00:32 PM »

When you say it goes to 3333. Are you saying the fan starts pulsing on and off as in it is confirming the Fan is working via the fan test.........or you get that as an error code on your analog meter and the fan is not going on and off? And you only have to pull fuse 5 for seconds.......not minutes to reset it.

mophead · « **Reply #21 on:** April 08, 2018, 07:50:12 PM »

When I hook up the motronic test connector to pin number 1 and ground it, turn on the ignition, wait five seconds, then unhook the ground, the fan immediately starts its on off sequence. Then the temp light lights up solid and starts to flash 3 flashes. It does this four times then the temp light goes solid for 2.5 seconds and then starts giving the second set of flashes, which are 3 flashes four times and then the light goes solid again and so on for the third and fourth sequence of flashes.
Temp light and fan on/off are all going on at the same time.

bizzaro · « **Reply #22 on:** April 08, 2018, 08:07:03 PM »

Yea, like I mentioned earlier...your doing it WRONG! You need to put a second ground on pin one. Read the link in Laitch's post carefully. Your putting the bike into fan test mode........not fault code mode. :deal: And I am not sure what the fault codes will tell ya anyway? Can't hurt to see um though. I am leaning towards your kill switch, or ignition switch, but hey, it could be A LOT OF THINGS.

mophead · « **Reply #23 on:** April 08, 2018, 09:10:38 PM »

I was doing it wrong. I hooked up ground to bike and then turned on the ignition. When I turn on ignition and then ground for five seconds I get the code 2343 mixture setting at limit. Hunting that down now.

mophead · « **Reply #24 on:** April 08, 2018, 10:31:38 PM »

Pulled fuse #5 again. Now I get 1133 fault. Hall Sensor #2. Test article says 1133 can be spurious and meaningless. The Hall Sensor has been replaced already on the bike by dealer in Albuquerque.

Done for today.

News:

Author Topic: Surging Brick (Read 37294 times)