TPS recall done, now my idle is choppy

Just got the bike back Friday, rained all weekend so today was the first day for a little ride. First thing I notice is a choppy idle. I figured it was my Power Commander throttle position settings needed to be updated being I just had the sensor replaced. Well it was only off slightly. The PC was reading between 0 and 1 while the bike was idling. I reset it and restarted the bike. No change in the choppy idle. Even just off idle, the engine isn't smooth anymore and it's very noticable under a load like when your creeping alone, slipping the clutch just a tad.... Not happy... :angry: That engine ran like a clock, completely smooth.

So next I decided to check the throttle body sync. Hooked up my mercury sticks only to see them perfectly in sync. Ok, now I'm definately not happy.

The ony thing I can think of is that the dealer didn't setup the TPS correctly. Per the FSM I need to measure the total resiatance of the TPS then multiply that by .13 ~.14 to determin what the closed TPS value should be. I hope thats the problem with my choppy idle condition. I'm going to check the setup of the new TPS myself in the morning. I hate to bring the bike back to a place that screwed it up in the first place.

Cliff notes:

Took the bike in running perfectly for a recall, it came out running with symptoms of what the recall is all about... :angry: :huh:

TPS angle appears correct. Sweep in DIAG is 16 - 100

Took the bike back and the tech that worked on it listened and told me he thinks the bike sounds perfectly fine. I even had him start another FJR to listen to the differance. He agreed that the other bike sounded a bit different, but again told me my bike still sounded normal. I know damn well it's not idling like it did, plus if you just slip the clutch at idle it really shows how choppy the idle is. It almost stalls when you creep it along at idle. It never did that before, the thing ran like a fine time piece and it's not like that anymore.

What in the world could they have done? I'm at a loss here.....

Afast03nNJ said:

TPS angle appears correct. Sweep in DIAG is 16 - 100Took the bike back and the tech that worked on it listened and told me he thinks the bike sounds perfectly fine. I even had him start another FJR to listen to the differance. He agreed that the other bike sounded a bit different, but again told me my bike still sounded normal. I know damn well it's not idling like it did, plus if you just slip the clutch at idle it really shows how choppy the idle is. It almost stalls when you creep it along at idle. It never did that before, the thing ran like a fine time piece and it's not like that anymore.

What in the world could they have done? I'm at a loss here.....

Click to expand...

Could the replacement TPS be bad? <_<

I would have them put the old part back on, since it was working fine before. If they won't, re-install it yourself.

This is exactly why I will not be participating in the recall. Why mess with something that is working fine? 91,000 miles on my 04 FJR and no complaints about the TPS.

I might be wrong here, but I believe Ionbeam ran into some of the same problems you did when he replaced his old TPS that had gone bad with a new updated (06) TPS. I think he reported his FJR became much rougher with the new TPS.

Good luck.

Try adjusting it a touch-1 or 2 in either direction, see if it smooths out.

I might be wrong here, but I believe Ionbeam ran into some of the same problems you did when he replaced his old TPS that had gone bad with a new updated (06) TPS. I think he reported his FJR became much rougher with the new TPS.

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Indeedie, true. It turned out not to be the new TPS though. When you drain the swamp alligators and rocks come to the surface. Evidently I had another problem for a while but it was masked by the even worse symptoms caused by my bad TPS.
As Skoot notes, right after I changed my TPS my bike had renewed, strong surging, abrupt throttle, traces of knocking with 87 octane and a significant drop in gas mileage. In retrospect I had also noticed that my engine had started to sound like a diesel at idle. I attributed it to the secondary air system. Since it was not causing me a problem I was going to put off inspection until this winter.

Once again I put my DMM (digital multi meter) on my TPS and went for a ride. Within minutes the TPS was exonerated. Next the vacuum gauge went back on the intake -- intake and fuel were pretty quickly eliminated. Testing the sensors that may be associated with surging found no problems. Off goes the PCIII USB-- no improvement. TBS is near perfect. Hmmm, that left ignition or something mechanical. I've seen cars with really worn timing chains cause ignition and valves to demonstrate similar symptoms. Before getting carried away there was one last basic thing I wanted to check -- I wanted to pull the plugs and check the color. Out comes plug #1 -- nasty black. Out comes... whoa plug #2 cap was not connected!!! Plugs #3 & #4 were black and showed some signs of glazing. With all plug caps firmly on I started bikie and behold, it ran great. Just before putting the tee bar back on I checked plug cap #2 again, and son of a *****, it was off. I checked the spring wire in the cap and it was fine. With the cap back on yet again I took a short break. When I came back the friggin cap had popped off yet again. :angry03: :butcher: I located a screw-on cap for the offending spark plug and the wire cap seemed to stay on after that. All went back together.

My engine runs very smooth now, idle is stable; gas mileage has gone up to an unheard of 42 mpg; diesel noise is gone; surging is gone; abrupt throttle is gone too. Someone seems to have put helium in my front tire

When troubleshooting, check the last thing(s) you did just before the problems started, check the basics before getting carried away. As always, it is the last thing that you check that fixes the problem. :blink:

Thanks for that info ionbeam, plugs were next on my list to check but I solved the problem. I decided to take the TPS off and check everything, including the shaft seal on back of the TPS. It was actually cocked slightly and probably wasn't sealing 100% so I had a very small vacuum leak. Whats strange is that it didn't show on my mercury sticks. I put some white grease on the seal and reinstalled the sensor. Next was calibration. The new sensor was set to a sweep of 16-100, my power commander was seeing almost 1% throttle open at that setting. I had recalibrated the p/c to the new sensor, but that didn't help my idle either. So I decided to pull the TPS back to 15 at the closed position, thinking thats probably where the old one was set as per my p/c reading. Now I have a sweep of 15-100 in diag mode. The choppy idle is now gone and the bike runs as it did before the TPS recall. I'm not 100% sure if it was the seal, calibration or a combination of both. The bike will be getting a new set of plugs and an air filter for next spring. As for now, I'm a happy FJR owner once again.

Lesson learned, DIY, screw the dealer, it wasn't worth the aggravation and most of all, if it ain't broken, leave it alone.

Thanks for the info guys, this site is great.

The rough idle senario brings to mind an old mechanic trick. If unable to solve an unstable idle/rough idle issue, take a spray can of carb cleaner,(careful around the exhaust Eugene), WD40, etc, and spray around the engine intakes, injectors, etc. to expose a vaccum leak. This is just one test that can help locate a problem not otherwise found with other measures....PM. <><

painman said:

The rough idle senario brings to mind an old mechanic trick. If unable to solve an unstable idle/rough idle issue, take a spray can of carb cleaner,(careful around the exhaust Eugene), WD40, etc, and spray around the engine intakes, injectors, etc. to expose a vaccum leak. This is just one test that can help locate a problem not otherwise found with other measures....PM. <><

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Good advice, but avoid using carb cleaner anymore, at least on the Feej. It will destroy the vac tubing and manifold rubber, and if it does find a leaky seal (as on NJ's bike), if the seal isn't shot, it will be after that stuff hits it. Brake Cleaner is the best all around solvent/test spray you can use on this bike.