I bought a used 2002 954 that had been sitting for some time before I bought it. After I bought it I noticed that it needed some work. The biggest problem was the dreaded Fuel Pressure Regulator fail. The 2 inside cylinders were firing, but the 2 outside were flooding. I changed the FPR, spark plugs, synced the throttle bodies, added new exhaust, and installed a Power Commander V with the correct map for the exhaust. The bike runs well once you get rolling, but I notice a slight hesitation when starting from a stop. It feels like it's getting some fuel, and then all of the sudden it feels like it gets the rest of the fuel and wants to take off. Could it be a slightly faulty TBS, or is this just a normal occurrence?

Thank you in advance!

 

Did you install a full exhaust system or just a slip on muffler? Does bike still have the htev between the header and midpipe?

 

Thank you for the reply! It's only a slip on. The PC-V was programmed for that exact exhaust on another 954. Other than the slip on, the rest of the exhaust/bike is bone stock.

 

Measure vacuum-levels at TPS
Measure MAP sensor voltage-output at idle and 3000rpm.

Out-of-calibrstion TPS and/or clogged/leaking vacuum hoses in 5-way Tee will mess with MAP sensor output and confuse ECU.

 

I was thinking that it could be the TPS. Instead of linking my TB sync tool directly to the TB's, I linked them to the vacuum hoses that were already attached from the 5-way tee to the TB's. Made it a lot easier that digging through and trying to squeeze the hoses into tight places. That being said, I know the hoses are good. I'm thinking the TPS is a little off. I wish there was an easy way to calibrate it.

 

What vacuum levels did you measure on each cylinder at idle and 3000rpms?

What vacuum levels did you measure at MAP sensor itself after 5-way Tee all joined into 1 hose?

What voltage did you measure for TPS at idle? At sensor itself and at ECU connector?

Follow manual’s troubleshooting guide for testing TPS. There’s additional measurements for reference voltage. Ground wire continuity and shorts.

Somewhere, some place, you’ll measure a number that different from what manual says it should be. The more numbers you measure, the more likely you’ll identify what’s wrong.

 

I've slept a few times since I did the sync, but I think I got all TB's lined up right at 18 cm Hg at idle. After I adjusted each cylinder I would pop the throttle to make sure it went back to where I had adjusted it to. Cylinder 1 was my base and wasn't touched.

Didn't measure total vacuum from the 5-way Tee after I adjusted the TB's. Didn't feel it was necessary considering that the TB's had been quite a bit out of sync when I started and the bike had been running rough during throttling. The sync did make a big difference because the hesitation was pretty strong.

I have not measured the voltage on the TPS at all, or the ECU connector. I don't have a voltage meter, nor would I know how to use one. Electrical work is not my talent. That being said, I did change the TPS on my FJR1300. I marked the exact location where it bolts on with a marker before I took the old one off. That way I would install the new one on in the exact same position. Worked like a charm! If I knew how to measure the TPS voltage I would definitely do so. I certainly don't want to remove it unless it actually needs to be replaced. One bolt is to lock it in, while the other bolt hole is slightly elongated to allow for movement/calibration. It's a tricky task for sure!