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F4i. Wiring problem.

  #1  
Old 02-01-2010, 11:19 AM
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Default F4i. Wiring problem.

I need a little input on a problem I have.

I'm new to bikes, but not new to mechanic work so I'm trying to fix this problem myself (if I can).

I just bought a used '02 F4I. When I checked it out, I looked at everything I could, looked decent and the f1 light wasn't going off at this point. 2 days later, and it starts going off. (Blinking twice)

My first question is, can the bike some how be rigged to where the f1 light won't come on for a certain amount of time? I'm trying to figure out if the problem was there when I bought the bike or if something messed up right after I got it.

Secondly. I looked it up and the error is with the MAP sensor. it looks fairly new so I contacted the previous owner and he said it was replaced 1 year ago. Could it be bad again this early?

I was also looking around and A LOT of the wiring is wrapped in electrical tape telling me the previous owner(s) did a lot of re wiring. It also has evidence of previously having a power commander in it at one point. I know almost nothing about power commanders, but is it possible that at one point the power commander bypassed the MAP sensor, and when it was removed, the map sensor was just not hooked back up?

Previous owner said he had it for a little over a year and from what I understand, the owner before him installed, and uninstalled the power commander, so that guy had the problem, but said his mechanic fixed it at one point.

Last question, am I royally F**Ked? Lol. Should I just get rid of this bike and its problems or should I stick with it and try to figure it out. I can do mechanical work, but I am very inexperienced with complex wiring.

Any input is apreciated, please. I can take it to the dealership, but I don't want to pay more on repairs than I paid for the bike.
 
  #2  
Old 02-02-2010, 09:35 AM
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Does anyone know what is effected when you install then uninstall a power commander? This is my first 'real' bike and I've never dealt with a power commander before.

I'm thinking about just buying one and hooking it back up to the loose connections I found.
 
  #3  
Old 02-02-2010, 10:59 AM
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I don't think the power commander would bypass the MAP. These bike's are known for MAP sensor problems so I wouldn't get too worried about it having had a PC on it. If the previous owner put a used MAP on it then I wouldn't be surprised if it was faulty again.

As far as the MAP, I would check the electrical connection and also the vacuum hose. Make sure the hose isn't cracked and that it's plugged in on both ends. The end of the hose that connects to the engine splits and goes to all 4 throttle bodies, if you need more info about this let me know and I'll get out my manual.

The MAP sensor should be located on the left side of the bike and is attached to the air box.

If the connections look good then you probably need a new MAP.
 
  #4  
Old 02-02-2010, 01:51 PM
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Thanks so much for the response. Yeah, the connections look really clean and the MAP even looks pretty new. I unhooked the old map and I'm planning on using a volt meter on the connections to see if I'm even getting anything. If I am, I'll (re)check the vaccuum lines to see if they are in good condition. All else fails, new map, I hope I can get it locally because I JUST got this bike and I'm dying to ride something other than my 250, which I JUST sold so now I'm bikeless =(

Will I be able to get a volt reading from the wires going to the map with the key on or do I need to run the engine? Will it run okay for a short period of time with the map un plugged? Sorry for newb questions. I'm used to carbed engines. Haha.

Thanks for the response.
 
  #5  
Old 02-02-2010, 03:00 PM
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download the service manual pdf. There is a diagnostics section dealing precisely with testing the maps sensor and the whole FI system. PC will not bypass the map sensor. Check the vac line routing and make sure it matches the diagram in the manual aswell. alot of times people get those all screwed up and the map wont be metering right which will throw an error. everywhere you see tape, remove said tape and thoroughly check connection and re-seal(be it tape, shrink tubing,etc). Once you've checked it all out, there is a pcm reset you will need to do that is outlined in the service manual.
 
  #6  
Old 02-02-2010, 03:05 PM
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I will get you the info from the manual tonight when I go home (I'm assuming you don't have one). There is a detailed procedure for testing the MAP sensor. It does require a multimeter, so you'll need one of those. I'll be home by 8 or 8:30 tonight (eastern time) so I'll post the info then.
 
  #7  
Old 02-02-2010, 04:04 PM
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A friend of mine is bringing over a multi meter tonight for me to use. I SHOULD be able to figure it out with that. If you want, you can wait to post the info until I report back on my findings from when I continue wrenchin on the bike tonight. I might be able to figure it out with the info you guys have already givin me.

Thanks for all the input, this is probably not even too big of a deal and I should be able to get through it.
 
  #8  
Old 02-02-2010, 11:01 PM
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Okay. So i may need more help after all. I don't have the repair manual, but my friend brought over the page from his schools' manual to test the map.

We tested the voltage at the MAP sensor and the ecu and they both read around 2.3-2.5.

His page said that it is normal and the sensor is good?

We didn't have a vacuum gauge, but i plan to get one tomorrow to test the vacuum. I inspected all the hoses and they all looked healthy and well connected so it may or may not be the vacuum.

If it isn't the vacuum, what else could it be? Is the ECU bad?
 
  #9  
Old 02-03-2010, 08:38 AM
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Just because the voltage going to the MAP is correct doesn't mean the sensor itself is working. Actually if that proved anything it's that the ECU is working correctly, but then again, ECU's are common on these as well. According to my manual, the MAP can only be tested using honda test equipment, which only the dealer would have.

Does the bike run? If it runs fine I would either just ride it with the FI light on, or get a new MAP off ebay or something. Here's a link to one for 35 bucks.

http://cgi.ebay.com/ebaymotors/Honda...#ht_2277wt_940

I'm not sure how much vacuum pressure that hose should have, as far as testing it with a gauge. I would say just start the bike and put your thumb over it and if you can feel it sucking it's probably ok. If there is a vacuum leak it should be pretty obvious to find. Just trace all the vacuum hoses and look for cracks.


My opinion is buy a MAP and if that doesn't fix it then at least you know the MAP is not the problem. Have you tried clearing the code and seeing if it comes back?
 
  #10  
Old 02-03-2010, 09:52 AM
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I'll go ahead and order a new sensor. Yes, the bike runs, it just has a fluctuating idle and the exhaust popped once. Meaning I'm lean?

And no, I haven't tried clearing the code. How do you do that? I really need to pick up a manual. Haha.
 

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