2007 VFR is crapping out!

I work at Honda's North American headquarters (on the automotive side) so today I talked with the guy who is in charge of the current VFR. I explained what was going on, what I had already checked, and such.

In short (pun intended), he said that it's likely one of two electrical things:

1. A ground issue. However, if it was/is a ground issue then it would affect the entire bike when the engine began to crap out. Thus, he had me free rev the engine until it crapped out while simultaneously watching the front headlight. If the headlights flickered and/or conked out ... then it was a ground issue.

My headlights are fine.

2. His hunch is a faulty Camshaft Position Sensor. Either one of the position "tangs" on the cam is bent/broken or the sensor itself is faulty. Later today we are going to put a scan tool on the bike, rev it until it craps out, and then do a "capture" of the data to analyze the problem.

While I won't be happy if I need to replace the CPS (which is located on the front of the rear head in the "V valley" between the two cylinders ... which is not overly easy to access), at least I'll have the issue figured out! I'll report later with my learnings.

 

You're lucky to have access to such resources. I've taken a course at the training center there in Torrance and it's quite a facility. If you can get a product specialist to help you out you 'got it made'.

Yea...the HDS tool is nice that way. You could also hook up the 'button' , go for a ride and take a 'snapshot' of the data list directly during the failure and then examine. I think you can read cam and crank position sensor voltages even if they don't set a code. Please do let us know when you find the problem...and how it was determined.

 

Dizzy,

That's exactly what we are going to do tomorrow. First, we'll use the scan tool to check for any codes. Then, we'll do a "snap shot" so that he can determine exactly what item(s) are being affected during the crapping out above 5,600 rpm.

I'm hoping to get the bike fixed ASAP as I was planning on riding it to the NHRA Finals on Saturday.

 

So here is the latest update. A HDS tool was hooked up and revealed that no codes had been thrown. Next, the bike was fired up and a 30 second "snapshot" was taken of the engine operation ... during idle, part throttle, mid throttle and (of course) in the rpm range where the bike craps out.

Looking at the data, (according to my contact) everything looked fine with the exception of the throttle position sensor (TPS) voltage was all over the place. In steady state the "curve" looked ok, but with any movement of the throttle the values went up/down like a richter scale.

Although it could be due to a loose wire connected to the TPS, he didn't think that was it (he said a voltage change in the TPS would throw a code ... which it didn't). Thus, he thinks it's a bad TPS unit. At this point, it is still a guess ... and an expensive guess as it appears as if you can't simply buy a new TPS sensor as it only comes sold bundled with a with the overall throttle-body assembly. Can you say big $$$!

Questions:

1. Has anybody ever had or heard of such a TPS problem?

2. Does anybody know a way to buy just the TPS sensor without buying the whole throttle-body assembly?

3. Does anybody happend to have a used TPS sensor and/or throttle-body system for a 2007 Interceptor (maybe off of a crashed bike or a blown motor)?

4. Anybody else have an idea what it could be?

 

The TPS is part of the throttle bodies. I thought I had messed mine up when I pulled the throttle bodies off to R/r my Tstat. If you dig deep on the internet one of the English VFR sites list how to replace the TPS and how to set up the new one based on volts out. Probably easier to find a used set of throttle bodies. Be sure to reset all your TPS connections before you do anything drastic.

Action

 

Just curious but can't the TPS be checked with an OHM meter? You should be able to see a smooth change in numbers when moving the throttle. I don't think that's it personally unless your really unlucky. I would check it with an OHM meter and then check the wiring harness that's associated to it before even thinking about paying $1000 plus for a new throttle body.

 

Actually... I would balance my starter valves before spending all that money too. Worth a check IMO.

 

A few months back I had to have the timing chain tensioner gizmo replaced. During that process, I'm pretty sure that the mechanic had to remove the throttle-body setup which leaves me wondering ... in the process did he clunk/clank/bump the TPS unit, pinch some wires, not plug something back in quite right or such.

After getting the bike back from the Honda dealership, it seemed to run fine. But maybe something loosened up and/or rubbed a wire raw over the course of a few months.

Have I mentioned yet that this is really getting old?

 

I regularly see TB sets on EBAY for around 100 bucks. Keep your eyes peeled.

As a trouble shooter on a 55 million dollar fighter jet with more bugs than a dead pigs carcass, I can tell you that checking all of the connections for anything the "mechanics" touched during your other repairs you run a good chance of wasting time and money. M2c.

 

No, I do not think you did but it did not need to be said.Yeeeeesh.
Does Honda offer a breakdown of assembly that would list part number? I have this happen to me quite a bit and a good parts guy can break it out, and then search the number alone. Could get lucky and have it be a common part to other machines. Could have the number on it as well. May not be the Honda number but the Nippondesno number on it may help.

 

Oh, trust me ... I've checked the parts diagrams and there is no separate breakdown for the TPS listed. You want a new TPS, then buy a whole new upper throttle-body assembly. Doh!

 

BTW: any VFR World'ers going to the NHRA Finals this weekend?

 

In my experience...those TPS are about as reliable as can be. I've never seen one fail outright. And if it were me doing the troubleshooting, I'd eliminate wiring or a connection as being a problem. ESPECIALLY since it's been apart. I've seen several occasions, some right from the factory, where a connector wasn't plugged in quite far enough to lock the tab, or a pin was pushed out...causing weird and intermittent problems. Considering the cost of the replacement part, and the fact you're gonna have go in that far anyway...well, it's just a 'no brainer'.

Jasonsmith is right...TPS can be ohmed (is this a word?). The manual might give resistance specs, otherwise the lower is usually several hundred ohms, up to WOT being 7 or 8K ohms. The variable resistance makes a good connection crucial. Maybe your friend at could loan you a wiring diagram and a 'pin fit' tool. Trace the wire colors to the correct wires at the ECM, and make your first resistance check there, trace any abormalities back to the TPS itself, thus eliminating a harness fault.

 

Look on page 6-80 of the 2002 Service Manual, it tells you step my step how to test the TPS. The book says that the testing harness is required. I couldn't get my hands on one of those and neither could my dealer. What I did was take some sewing needles and used them to skewer the wires you were to test. Then I would just stick my multimeter to the needles.

You can test it but i'm not sure if you will be able to see what you described. At least not with a digital mulimeter. If the voltage jumps all around while twisting it... you wont be able to see it on a digital unless it is really high end and has super fast (realtime) updates. Both of mine only update 3-4 times a second.. but are nowhere near high end. An analog guage would be realtime and you would see the needle bounce around like crazy if it is doing like he said.

 

John,
Here's a link where they are talking about Adjusting the TPS. If yours is just out of tolerance and not broken it sounds like you can adjust it.

TPS adjustment

Action

 

goinphaster,

What type of fighter jets do you work on?

 

So here's the update:

The VFR has been at the dealership for a week. After explaining all of the things that I've already done/checked ... they have spent 3 hours combing over the bike.

They checked the voltage regulator (to check if it was within tolerance ... which it is) and then said that it must be a bad ECU computer [can you say $650]. So, a new computer was ordered, installed and ... blammo ... the engine-crapping-out problem still exists.

Yesterday I got a phone call saying that they don't know what to do. Nice.

 

John:

I have a suggestion, order this book at the amazon link provided:

Amazon.com: Motorcycle Electrical Systems: Troubleshooting and Repair (Motorbooks Workshop) (9780760327166): Tracy Martin: Books

Tracy is a really great guy and knows his electrical 'shit' shall we say. The 20 bucks for his book is invaluable when trying to track down electrical problems and he is a bit scathing on dealerships have staff ill-trained when it comes to electrical gremlins.

I bought Tracey's above book after he and another fellow taught me how to hang off my bike. I saw his book and we chatted and since I have a VFR, well how to diagnose electrical issues in book form may not be a bad thing!

Its easy to read and Tracy is very methodical in showing you how to eliminate what the issue is instead of replacing expensive parts and the problem persists.

p.s. Did the dealership do an ohms test on the RR? If so that test tells you crap. Bad RR's test perfect on ohm settings on a multi-meter. I have Tracy to thank for that knowledge.

BZ

 

ah jeeze, sorry to hear that the dealer is stumped. Did you by any chance do what NCB suggested...

My experience with cars is saying that it seems like a timing sort of issue. I did have a truck though that when I would bounce the throttle it would just die, it was the MAP sensor and a $50 fix. It may also be time to talk with Honda again. Ruling out the ECU is good. I'm thinking that the issue is a smaller one.

If we can trust the on-board FI diagnostics then it's not a fuel issue and not a ECU issue. That's all good to know and to relay to Honda when talking with them.

 

sound like map sensor unplug it and see what happens.
if totally shot it might run better disconnected