Fuel Injection

[g15usmc]

Short multi-degree answer: No.



No one except you has said that EFI is "crap."

your absolutely correct...EFI isn't crap...nor is carburator...and you are also correct that efi was never described as crap as well...my appologies on that...I actually own 2 bikes one with efi and the other carb...i was just ranting...

about the Cap question...why can't i use a multi-meter to test a cap? can't you watch a cap charge and discharge using a multi-meter? Or have I been wrong the last nine years in troubleshooting the caps?...I know that you have to isolate the cap in order to do that but couldn't you just ground both sides of the cap and then do the test? That's how I've tested every cap i've ever checked...then either it shows up as a short because its bad...an open that never lowers resistance because its bad...or it starts as an open if its fully discharged and slowly lowers its resistance as it charges and then discharges and starts over...if its good...Please help me understand...really I'm not just trying to be an douche, i'm really curious...

[cywelchjr]

your absolutely correct...EFI isn't crap...nor is carburator...and you are also correct that efi was never described as crap as well...my appologies on that...I actually own 2 bikes one with efi and the other carb...i was just ranting...

about the Cap question...why can't i use a multi-meter to test a cap? can't you watch a cap charge and discharge using a multi-meter? Or have I been wrong the last nine years in troubleshooting the caps?...I know that you have to isolate the cap in order to do that but couldn't you just ground both sides of the cap and then do the test? That's how I've tested every cap i've ever checked...then either it shows up as a short because its bad...an open that never lowers resistance because its bad...or it starts as an open if its fully discharged and slowly lowers its resistance as it charges and then discharges and starts over...if its good...Please help me understand...really I'm not just trying to be an douche, i'm really curious...

Well, an analogue meter can kinda do that test, but it's really just a sort of go no-go test, and won't show out of spec ones, only those that are totally failed. I use to work with cap testers and they were nice, since they could tell you the actual measured value of the cap, so you would know if it was in spec or not.

[g15usmc]

Well, an analogue meter can kinda do that test, but it's really just a sort of go no-go test, and won't show out of spec ones, only those that are totally failed. I use to work with cap testers and they were nice, since they could tell you the actual measured value of the cap, so you would know if it was in spec or not.

thax cy...i suppose that makes sense...a multi-meter wont tell the farads that a cap is charging to...

[cywelchjr]

thax cy...i suppose that makes sense...a multi-meter wont tell the farads that a cap is charging to...

Right, measuring that requires measuring how long the cap takes to charge through a specific resistance, this tells you how much it's holding. Frankly while most of the time they fail either open or short, I have seen and heard of them just going out of spec enough to cause problems. This is more likely with larger value caps than the smaller, but it has been known to happen.

[3Phase]

Please help me understand...really I'm not just trying to be an douche, i'm really curious...

G15, Cy's mentioned the basics. Given the fact that you quite obviously know that capacitors and other discrete components usually have to be isolated to be tested reliably, something that is definitely not a given when they are tested in-circuit, the answer to your general question about troubleshooting the EFI module is no longer short and simple.

The Long Answer: Maybe, it depends.

Referring back to Larry's post and the picture of one example of an EFI module in full light on a clean test bench: you will need the schematics, circuit test reference points and flowcharts. If you don't happen to have a laptop computer with you to interrogate the module at the very least you will need a very, very thorough understanding of the actual control module and fuel distribution system installed on your bike to test EFI. General theory and guesswork after a rainy late-night engine failure a few thousand miles from home is going to leave you and your passenger sitting in the cold, dark, rain on the side of the road with a dead battery.

Digitally controlled EFI is a marvelous technology but it has limitations. I have never once had to check for loose wires or a bad fuse on the analog computer that is each and every XS11 carburetor.

[g15usmc]

G15, Cy's mentioned the basics. Given the fact that you quite obviously know that capacitors and other discrete components usually have to be isolated to be tested reliably, something that is definitely not a given when they are tested in-circuit, the answer to your general question about troubleshooting the EFI module is no longer short and simple.

The Long Answer: Maybe, it depends.

Referring back to Larry's post and the picture of one example of an EFI module in full light on a clean test bench: you will need the schematics, circuit test reference points and flowcharts. If you don't happen to have a laptop computer with you to interrogate the module at the very least you will need a very, very thorough understanding of the actual control module and fuel distribution system installed on your bike to test EFI. General theory and guesswork after a rainy late-night engine failure a few thousand miles from home is going to leave you and your passenger sitting in the cold, dark, rain on the side of the road with a dead battery.

Digitally controlled EFI is a marvelous technology but it has limitations. I have never once had to check for loose wires or a bad fuse on the analog computer that is each and every XS11 carburetor.

Yeah...I mean obviously there is more too the EFI system than just the computer too...I'm just thinking that it kinda has to be a personal preference...Up sides and down sides to both...Granted I've never ran into either problem...as far as my EFI going out on the one bike or the carb system bikes i've had going out on the side of the road either...and i'm thinking i guess i dont know if i'd really want to re-build the carbs on the side of a road...and i know i couldn't diagnose and fix an EFI on the side of a road...so i guess i hope i have cell service for someone to bring me my truck...and if not...and i have not choice...i hope i do have the carbs so i can rebuild them...so ya'll have a point either way i guess...

[cywelchjr]

I think that the EFI reliability issue is a little bit of a red herring. Why you ask, because unless it's a DIY kit, the likelyhood of a modern digital controller failing is really pretty low, and since they also replace the ignition system typically that removes a point of failure at the same time (no matter that the stock TCI is pretty simple, I would not try to fix one on the side of the road). Based on the cost of the controller, if I was to spend the money to go to EFI, I would get two controllers and make sure both were tested and setup with the same maps, and then carry the extra with me.

Now that said, frankly the carbs are not likely to fail going down the road unless something was already wrong with them anyways, but the TCI or coils (pickup or spark) could fail, once again, not something I would try to fix on the side of the road anyways.

I think it's really about either keeping it as close to stock as possible or modernizing it as much as possible, you either want to do one or the other, and to me, keeping close to stock can include newer coils with higher voltage and replaceable wires, as long as your keeping the functionality the same style as original. Personally, I plan on someday going to EFI, but it's going to be a few years before I do it.

[fredintoon]

Thing about EFI is, OK, it's dead reliable but if it goes wrong I can't fix it.
If the iggy goes wrong I can troubleshoot until it's narrowed down to the iggybox and plugging in a spare one will check that out.
If the carbs act up I can fix those bastards in my sleep.
If I had EFI and it acted up I'd be in the same fix as a tribesman having to give a chicken to the witch-doctor to take the evil spell off.
Modern witch-doctors want really expensive chickens.

[3Phase]

g15, as you say there is a lot more to EFI than the module. What's more likely to cause problems is bad fuel or rust and dirt from the thirty-year-old fuel tank plugging the fuel filters, injectors, and the pump. The fuel supply for EFI needs to be clean. Also, even after adding an XJ1100 alternator (the stock XS11 won't handle the pump current) there are still not a lot of amps left to spare. High current demand and low voltage will eventually burn out the pump and the wiring harness/connectors along with it. I do carry a soldering iron and I have full a schematic loaded in my mobile phone. I've had to use both a couple of times in anger so it's not an insurmountable problem, it's just not something I care to do on the road. I found it slightly annoying, especially along the freeway at rush hour.

If it was just the module you could carry a spare with all the right maps loaded so you could change it out if you had trouble. Unless it's something simple like a discrete component or one of the line driver chips, forget about trying to troubleshoot and repair the module unless you can do surface mount soldering. If you don't usually carry a laptop computer on your bike then you should build or buy a small adapter to manually enter and store several thousand bytes of binary code for the fuel and timing maps into the new chip(s). You will, of course, also need a hard copy of the maps. If you do this I, for one, want to see pictures and video!


I might do the conversion to EFI on the local runabout toy I'll be building this winter when I get a few more round tuits but not on my long-distance machine. It looks like fun and if it breaks down I can find a truck somewhere and haul it home.

For my serious travel bike I'd have to pack more spare parts and tools for yet-another-system than I already carry with me and/or spend time and money at a motel waiting for parts when the EFI system went tango-uniform; praying the management is cool so I can fix it in the parking lot without them calling the cops or a wrecker.

[shutchis]

EFI verse Carbs

EFI verses Carbs; Reminds me of the "best oil" discussions. I've got 25K+ miles on my DIY EFI systems. I'm mostly a fair weather rider, but I ride almost every day to work (25 miles round trip). I've suffered rain, hail, and Houston's 95F summers. I've seen gasohol, which is a poor product and a dumb idea. Someone must be getting rich.

Simple is better; carbs get my vote. However, for the record...EFI systems are VERY reliable. Yes, you have to worry about electric fuel pumps and CPU failures. In my case, bad solder joints and a few O2 sensor failures. But I would ride my XJ1100 anywhere. It's a great running, 29 years old motocycle.

Harley Davidsons are less reliable; which is another discussion. Have a great New Year; Ride Safe. Stan H.

[3Phase]

Right on, Stan! I like success stories with some longevity behind them to back them up!

When you added EFI to your bikes did you roll your own controllers and plumbing; buy Megasquirt; gleep parts from other vehicles and force them to submit to your will; a combination of all three?

Were there very many chicken bones and tea leaves involved in the design and assembly process and are they required maintenance items?

[webbcraft2150]

I deal with both carbs and FI. My '75 Dodge is topped off with Holley that I can rebuild AND TUNE in a couple of hours. The carb set up does present some issues when offroading but I have leaned to deal with that. I have only been in the carbs on my 80G once since I got it so I guess I got it right the first time. My boat has TB/FI and its been rock solid since '96 with the exception of one injector going bad. Boat before that one had a carb and it wasn't a big problem at all, one rebuild in 15 years of owning it. It does suck when FI craps out, a set of injectors can rival the cost of a good carb in a heartbeat. Figureing out which sensor has crapped out can be a hassle to. I have three cars with FI and have figured out how to do most of my own work when something goes wrong. For me, I would stick with the simplicity of a bank of carbs on my XS.

[fredintoon]

- - - For me, I would stick with the simplicity of a bank of carbs on my XS.

Hi Keoki,
the 4 carbs are mainly a fashion statement and a poor balancing job can spoil your whole day.
What I'd prefer would be a 1 into 4 manifold and a sodding great side-draft Stromberg.

[shutchis]

MegaSquirt EFI Controller

I bought a MegaSquirt MS1 EFI kit and assembled everything. I have a website http://users.hal-pc.org/~dhutch/ that described the project. It needs updating after four years of riding.

This link is also available from the XS11 Forum under the Modifications / Carburetors and Fuel Systems. Look for the title: XS/XJ Electronic Fuel Injection.

Carbs are very good and reliable. However, It's pretty cool to use a laptop to tune your engine and have great performance at ALL RPMs and loads.

Hmm...I should have an EFI briefing at a future carb clinic. Does anyone know if Wildcat is having a 2011 get together? Ft. Worth is very central to "everything". Oh, FYI...I rode 3,418 miles on the XJ in 2010 and 1,011 on the XS11. slh

[Wildkat]

EFI systems are VERY reliable.

Unless you're at an XS rally


lol
Sorry Stan, I couldn't resist

Does anyone know if Wildcat is having a 2011 get together?

No, she isn't...
I've taken on Band Mom duties which have left me little time for bike related things.
There is a gentleman who offers a specific carb clinic though. I believe it's in June?