Help me learn to tune my bike

[Choirboy]

Hello!
2001 Jackal is running terribly. Plugs black and sooty, misfiring and backfiring in equal measure (mostly at low rpm; haven't taken it on the highway since it started misbehaving). Started doing this last summer, put it away in disgust and ordered all the cables to do a tune up. Been busy so just dug it out now and am getting reacquainted with it.
Things I've already done/checked/noticed:
New plugs, valves set. Replaced some cracked fuel hose. New throttle body boots.

Fuel pump sounds like it is not quite "steady." I got a fuel schrader valve and put it inline from my fuel pump last fall. Had Neds in Riverside put a new fuel pump in.... maybe 4-5 years ago? Not a lot of miles since then since I had my first child around that same time. Don't remember what the fuel pressure was reading last fall and my fuel pressure gauge is at the farm; I'll pick it up and check it soon. What should it read? Should I test while key is on but not running, or running, or both?

 I have the tps set very close to 157mv. Just got Guzzidiag working and was able to see that my head temperature sensor appears to work (started at 26c cold, drove it around for 5 minutes and it read 76c).
Question on tps: I have it set close to 157 with the throttle linkage disconnected; what should it read with the linkage reconnected?

What should my next steps be?
Thanks for any help!

[guzzisteve]

https://www.google.com/search?q=throttle+body+sync&sitesearch=wildguzzi.com%2Fforum%2Findex.php%3Fboard%3D1.0&start=0&num=100

[Choirboy]

Thanks, I have read several of the threads on throttle body syncing on this and another forum. I do plan to get there, but the bike is running so terribly I'm not sure I could sync them when every other piston misfires. It is 'really' rough right now. And it wasn't before, and got rough in a hurry. It ran 'ok' and probably needed a tune up before last summer, but then it got quite bad in a hurry. Surely such violent backfiring and misfiring can't be a throttle body that got way out of sync all at once on its own, right?
What should I check next to try to fix the rough running?
Fuel pressure should be 44psi with key on; should I also test it while running to see if the regulator is acting funny?
Other than checking fuel pressure when I get my gauge tomorrow or the next day, what should I look into?

[Tkelly]

Maybe a new tps,sounds like a bad one.

[RinkRat II]

   Could be a number of  factors, plug wires, co setting, bad gas, etc etc. Cross forum info worth a read.....https://www.v11lemans.com/forums/topic/19610-decent-tune-up/.

   Hope this helps and keep asking questions! Most of us have been through this.

     Paul B

[Tom H]

This tutorial is for your bike. It is text only, but it is the one "I" go by:

https://archive.guzzitech.com/EVTuneup-Jeff_B.html

If you search Bikeboy.org IIRR he has one with pics. But not as clear and concise as to how to do the work.

You mentioned changing the spark plugs, did you check/change the plug wires or end caps? Many change the plug cap to the NGK version. Air cleaner? Rodent issue in the air cleaner or with the wiring?

You mentioned the TPS setting of 157mv. If your getting that reading with a digital volt meter with a breakout cable or pins into the TPS plug. The LH TB idle screw need so be fully backed out. Also the tie rod between the two TB's needs to be disconnected. This will allow the butterfly to be fully closed, provided it is not all gummed up or the like.

Then you adjust the TPS to get the 157mv. Then you follow the instructions to get about 525mv using the idle stop screw on the LH TB. Then you follow the rest of the instructions.

Depending on what was done just before the bike had it's issue. If you don't set up the TPS and LH TB correctly, you could make it run lean or rich. "FOR INSTANCE", if the LH TB idle stop screw that should be set at about 525mv was set at "lets say" 4.25V with the butterfly on the idle stop, the ECU would thing that that TB is W/O and throw enough fuels for W/O in.

You could also have a bad TPS. It could be telling the ECU that the butterfly is at X, when it's actually at Y and the ECU is fueling for X.

Just some thoughts.
Tom

[Choirboy]

Thought I would update this. I'm not afraid to admit when I'm wrong: the throttle bodies and air bleed screws were so far out of adjustment that it was causing most of my trouble. I couldn't set up the idle speed because the bike was running so terribly, so I set it up via the tps settings and then adjusted as well as I could. I couldn't believe the improvement. I'm not sure how things got so screwed up, but I will just mention that the bike started to run worse about the time my toddler learned how to use a screwdriver.... and if it wasn't him then I just don't understand, but it doesn't matter because it is running much better now.
Thanks for all your help!

[john fish]

Thanks for the update.  It's helpful for those of us who struggle with mechanical issues (and thinking issues in general). 

Glad you got things figured out.

[Choirboy]

And a second update. After two days of running beautifully, it started coughing, hiccuping, and finally running like crap. Seems to mostly be at higher throttle openings. So, looks like I had several things wrong, one being out of sync throttle bodies and the other.... something else. I'll take apart the TPS and clean it out with electrical contact cleaner and see if that helps.
I now understand why people pull off the FI and put on a set of carbs!

[n3303j]

Put an ohmmeter on the disconnected TPS and sweep it smoothly and slowly through its full travel a number of times. Look for responses that are not smooth and repeatable.

[Rolf Halvorsen]

One of mine experiences is connected to the spark plug - finger nut. If this is loose, then you can have a good spark from cold. But when the engine gets warmer - the loose finger nut gets even more loose due to temperature. I think this nut is made out of aluminium.

So, whenever you have a spark plug (with that finger nut) in your hand - tighten it securely.

[AJ Huff]

Mine experienced that once upon a time. I am pretty sure we replaced the TPS with the Harley one. Running fine for many years now.

There once were instructions posted on how to clean out the TPS but they may be lost now. I think Patrick Hayes had that write up..involved drilling a small hole IIRC.

-AJ

[Tom]

Yes.  Small hole through the plastic only using a light touch.  Use either carb spray.  Brake cleaner spray.  A Dremel type would work better for drilling.  Stick noozle hose in and blast clean the contacts.  Place in sun to dry.

Another thought.  How's your temp. Sensor on the head?
Plastic?

[john fish]

Anyone have a link to the Harley TPS?

[n3303j]

Seems to me this is the one.
https://ca-cycleworks.com/pf3c.html

[john fish]

I'm not sure.  I do know that my 2000 Jackal ran like shit until I replaced the TPS and set it to 525 mv.

[s1120]

Put an ohmmeter on the disconnected TPS and sweep it smoothly and slowly through its full travel a number of times. Look for responses that are not smooth and repeatable.

One more thing on this. Ive had better luck testing for full range with a old school multi meter with a needle. Its easer to see the sweep of the needle then watching for the digits to move steady.

[n3303j]

One more thing on this. Ive had better luck testing for full range with a old school multi meter with a needle. Its easer to see the sweep of the needle then watching for the digits to move steady.

Yup!

[Choirboy]

Thanks for all the suggestions! Replying to a few of the questions:
I have used my multi-meter to check for a smooth sweep of the tps; mine may not be high enough quality to check that it is perfect (seems to have some lag no matter what I'm testing) so I can easily check it again with an old 1970s analog type that I have. Good thought on that. With my digital multi meter there at least weren't any glaryingly obvious problems, but there were a few places I couldn't tell if the meter was lagging or there was a tps problem.

The head temperature sensor is brass and while I can't check to see if it is accurate, the indicated temperature on guzzi-diag does go up from engine cold to engine hot, so I'm assuming it is ok?

I haven't really checked anything with ignition. That might be the next place to start looking for trouble. It didn't run as badly today (84*F) as it did the other day (101*F) so perhaps I do have something getting out of whack the hotter the engine gets.

[John A]

It’s hard to test the tps with a multi meter. Most won’t pick up the small changes in resistance in a coherent way . If it’s suspect I just replace it unless I have an oscilloscope to test it with

[n3303j]

It's a rheostat. Multimeter will show you discontinuities in the function. Analog is better.

[John Croucher]

https://autoditex.com/page/throttle-position-sensor-tps-22-1.html

Mixing mechanical movements and electrical energy together.  A lot can go wrong. 

[scra99tch]

Take a look real close at the throttle body intake manifold.  It just so happens I had noticed a little soot around one of the mounting screws on my Jackal.  I took it off and there was a clear opening to the cylinder head letting air come in through a gas pocket in the aluminum casting hiding just behind the screw head. 

You could also use propane to find leaks around the intake system.  When idling you'll notice a change in RPM if anything combustible comes in.

[Choirboy]

Tested the TPS with an analog multimeter. Other than the wires being backwards of what I expected (purple with black stripe needed to be to positive probe and solid purple to negative) I had my dad very slowly and steadily work the throttle and I didn't see any jumps or other problems. I read you could pop the cover off the TPS; perhaps on some but I couldn't get mine open. It appeared I could get some contact cleaner in through the gap where the throttle blade engages so I sprayed it down several times and worked it smoothly. No change.

Its ready for fresh spark plug wires and caps anyway, so I'll order those. If those don't make a difference, how does one check the coil? A bit pricey just to throw parts on it and hope they fix the problem.

[Tom H]

Since you've had the TPS off. I would start over with the instructions I gave you a link to. Though, if you have not moved the LH idle stop screw, some have had success just adjusting the TPS to get about .525V

This may help your further testing:
http://www.dpguzzi.com/efiman.pdf

Tom

[n3303j]

Coils have ohms ratings for primary and secondary windings. But they can be fine at resting temperature and go intermittent at operating temperature. They can also test okay with a meter but arc over at operating voltage.