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Honda 420 Fuel Injection Help

79K views 41 replies 5 participants last post by  aTVitsnot  
#1 ·
My rancher would die after idling a while so I thought I'd replace the fuel filter and pump. After doing so it will not start. I pulled the injector and it's squirting fuel when It is trying to start so I know it's getting fuel. I've checked the spark plug it's getting spark. It will start if you pour fuel on the air filter for a few seconds.I also noticed when the fuel injector was out and I was turning over the motor if I pushed the throttle the fuel would stop, which seems odd to me. I'm new to fuel injected atvs though. Any help is appreciated..
 
#3 · (Edited)
Pretty sure hitting the thorrotle while cranking is suppose to shut the fuel off to the injector . That’s why they tell you not too while trying to start unless you’ve flooded it. As far as it dieing at idle you could look and see if the IACV motor is working and try cleaning where it goes into the thorrotle body
 
#5 ·
Butting in?

I am another rancher 420 owner with these symptoms. I hope you don't mind me adding to your thread. I'm definitely anxious to hear the solution you arrive at. My story follows but I will happily delete it if you view it as hijacking:

I've owned this 2007 420FM for 5 years.

It has been sitting for months (a year?) with treated (I think) gas in the tank. It was on a Battery Doc maintenance charger but the battery degenerated during the storage period. I installed a new battery and punched the button. It started with vigorous cranking but needed a few seconds of throttle blipping to ignite and settle into an idle. I figured fuel was starting to turn and added a gallon of fresh to the tank.

I used it to tow my trailer and collect tree debris from multiple locations and deposit them in a disposal site. This required probably 20 starts with short hops (20-30 yards) between them. I shut the unit off when not moving. Speeds were 1st gear slow. I rode it to the garage and parked it after 4 or 5 hours of this.

The Rancher wasn't responsive the next morning. It cranked enthusiastically. It had spark; good strong spark. I initially checked it with a spare plug on the lead. Then I pulled the one on duty. It has some crusty deposits on the ring but it still fired strongly. I replaced it with a fresh one. No joy.

I'm not hearing the pump do anything when the key is turned. But, there is a short buzz from something (IACV?) near the throttle body. I disconnected the fuel line at the throttle body. No fuel flowed when the key switched on and petcock in run position. I removed and disassembled the pump housing. The fuel filter (pre-update bottom mount) is blackened. The housing had a crusty build up over its entire surface.

I applied direct power to the pump leads. No response. I disconnected the pump leads and checked for continuity with my meter. It's good. I ran leads straight from the battery to the positive and negative contacts. Nothing but silence from the pump. I'm thinking this is proof of a bad pump. BUT...

Do you who have been down this road think that it could be the PGM or the relay? do you think it could be the bank sensor? Or...do you think Im right about the pump?
 
#6 ·
I am another rancher 420 owner with these symptoms. I hope you don't mind me adding to your thread. I'm definitely anxious to hear the solution you arrive at. My story follows but I will happily delete it if you view it as hijacking:



I've owned this 2007 420FM for 5 years.



It has been sitting for months (a year?) with treated (I think) gas in the tank. It was on a Battery Doc maintenance charger but the battery degenerated during the storage period. I installed a new battery and punched the button. It started with vigorous cranking but needed a few seconds of throttle blipping to ignite and settle into an idle. I figured fuel was starting to turn and added a gallon of fresh to the tank.



I used it to tow my trailer and collect tree debris from multiple locations and deposit them in a disposal site. This required probably 20 starts with short hops (20-30 yards) between them. I shut the unit off when not moving. Speeds were 1st gear slow. I rode it to the garage and parked it after 4 or 5 hours of this.



The Rancher wasn't responsive the next morning. It cranked enthusiastically. It had spark; good strong spark. I initially checked it with a spare plug on the lead. Then I pulled the one on duty. It has some crusty deposits on the ring but it still fired strongly. I replaced it with a fresh one. No joy.



I'm not hearing the pump do anything when the key is turned. But, there is a short buzz from something (IACV?) near the throttle body. I disconnected the fuel line at the throttle body. No fuel flowed when the key switched on and petcock in run position. I removed and disassembled the pump housing. The fuel filter (pre-update bottom mount) is blackened. The housing had a crusty build up over its entire surface.



I applied direct power to the pump leads. No response. I disconnected the pump leads and checked for continuity with my meter. It's good. I ran leads straight from the battery to the positive and negative contacts. Nothing but silence from the pump. I'm thinking this is proof of a bad pump. BUT...



Do you who have been down this road think that it could be the PGM or the relay? do you think it could be the bank sensor? Or...do you think Im right about the pump?


You mentioned checking continuity but did you check for power and ground at the harness side of the fuel pump connector ?
 
#8 ·
I use paper clips and jumper wires with alligator clips . Yes I think you’ll only have power for the prime and when it senses no fuel pump activation it will stop sending power. But I’ve never messed with one on a wheeler
 
#9 ·
I also have in my possession this;

Image


I put 12 volts to it as well as the OEM pump. Both were non responsive. I think China pump is DOA. I think OEM died on duty. This zapping should have induced some kind of response.

No juice at the harness connector would imply the relay, you think? So 2 dead components? One might deduce that something sinister caused this coincidence...cause there are no coincidences in the land of electrons. Plenty of mysteries though.

Anyway, I'll see what kind of response I get from the connector testing. More later
 
#10 ·
Are you putting 12v and ground to the pump at the right pins ? If no power at the connector then test power at relay . Then depending on what you find there there is other tests . I wouldn’t just assume a part is bad and change it . Not how I do things
 
#11 · (Edited)
I believe brown is positive and the remaining wire (green) is negative. I had 50% odds.

I hooked the meter leads to the harness side pump connector. Assistant turned key. Meter didnt know the juice was flowing...just like the pump.

I'm trying super hard not to just throw parts at this problem and appreciate your thoughtful consideration in sharing your trouble shooting expertise.

I'm doing this between a lot of other chores. I'll get on the relay manana.

I have a recon that can (barely) and is pulling the trailer. So not panicked about rancher. I do hate stressing little pinky (once red recon) and will be happy to get the rancher back on duty.

Again; I appreciate your helping me think this through.
 
#12 · (Edited)
I went searching for the relay which the manuals illustration(drawing) depict as having 4 wires from the harness. I found this which looks very much like the manual drawing as well s the partzilla parts diagram;

Image


It only has 4 pins under the connectors housing. I see a box that's 10 times bigger than the red one in the bottom of the electric well...just behind the battery. It only has 2 wires entering it.

I dug deeper. I found this

Image


I found the nest material before I returned the rancher to service last week. I tossed out what I could pull from the top of the compartment and started the 420 and did my chores. Next morning, the rancher was afflicted with whatever this current malady is.

This obviously needs attention but I'm not sure it is a cause of the non starting issue.

I dug deeper and found the relay. It was the one with 2 wires entering it...until I cleared everything out of the way; 8 wires as in 8P connector. EUREKA! It was clipped to the forward wall off the well behind the battery compartment. It was inverted. It is much bigger than the scale of the drawing lead me to believe it would be.

Image


Supporting evidence;

Image


Stuff scheduled that will preclude further work until tomorrow.
 
#13 ·
I would test the relay module like stated but knowing that there was what looks like a mouse nest I would inspect the wire harness very carefully for places where a mouse would have chewed
 
#17 ·
I couldn’t agree more . They built a nest in a persons air box on a Polaris and they used cracked corn . Sucked it threw the thorottle body and bent up all the valves
 
#18 ·
I have had a snack bar set up for my mice the last 5 years. It's all you can eat but only one item on the menu;

Image


I think They've built up an imunity. It's disappearing but no D.B's this winter.
 
#19 · (Edited)
Since I have access to the forums electrical genius....

After the mouse house was demolished, after the wiring was untangled, this is all the damage I could find. Seems the mouse-trician is a picky eater; just the blue wire with the red stripe.

It's super tiny and it seems to only have one of its (very few) strands severed. What repair is recommended?
1) Wrap with HQ electrical tape?
2)Cut out and solder in new segment? Would gauge be critical to match for this connector? Is the juice dosage to that component all that critical?
3) replace entire wiring harness ? Joking BTW, but which of the first 2?

Image
 
#20 ·
If the inner wire isn't broken it will still conduct, so I'd wrap it and run it.


That said, a non-severed wire doesn't solve your problem.




A quick way to bypass that relay, the roll over sensor, and all the other crap is to run a jumper wire from battery + to the red and black wire on the coil. If it will start with that in place then you start working on which component is bad.


On the wife's 420, that fuel injection relay you pictured was clicking, but wasn't making a good connection. After about the 5th time I removed it and plugged it back in while troubleshooting it suddenly worked fine and has ever since, so obviously I had a bit of corrosion in the plug that was wiped clean by repeated plugging and unplugging.
 
#22 ·
A quick way to bypass that relay, the roll over sensor, and all the other crap is to run a jumper wire from battery + to the red and black wire on the coil. If it will start with that in place then you start working on which component is bad.

On the wife's 420, that fuel injection relay you pictured was clicking, but wasn't making a good connection. After about the 5th time I removed it and plugged it back in while troubleshooting it suddenly worked fine and has ever since, so obviously I had a bit of corrosion in the plug that was wiped clean by repeated plugging and unplugging.
Thanks for the tip; both of them.

The 420 runs a few seconds when the intake is doused with chemtool brake clean. Does that not eliminate a bad coil?

My wife is milking the mothers day thing. I have to do stuff with and for her, but I'll get back on this by late afternoon.

Thanks again.
 
#21 ·
I’m far from a electrical genius but got a good understanding of it . Personally I’d cut that section out and solder a new piece in with shrink wrap . Like jeep said if it’s not severed then that’s not your problem . I’d do what Jeep says , seems like he has more experience with the new systems.
 
#23 ·
I'm thinking the mouse damage did not cause the issue because the bare wires aren't grounding/shorting on anything. But it still has to be repaired.

My anal side (LOL) agrees and is tempted to do a gauge match with the wire. Just in case the current flow to wherever that red striped blue wire terminates, is super sensitive.
 
#27 ·
Yeah, the fuel pumps on the EFI machines aren't stout at all. If you leave them for any length of time with ethanol fuel in them it will ruin them.


Get a used OEM fuel pump from Powersportsnation.com (they guarantee their used parts) and put it on.


I would try the jumper wire first to see if it will run. If it won't then your fuel pump is likely your problem.
 
#28 · (Edited)
EDIT: Post #32 in this thread explains my disagnosis below

As to the direct jumper wire to coil; the fuel pump is lounging in a parts pan along with the D.O.A. $18 Ebay Chinese pump. I'd need a functioning pump to run this diagnostic? OR...can I squirt some brake clean all up in there?

I'm headed to powersportsnation right now. Thanks again!

Agree on the alcohol (ethanol) poisoning. Absolutely nasty in carbs too. I have a habit of dosing every tank of gas with this stuff. Pretty sure I dosed the rangers last tank. EDIT: I mean 5 gallon can

Image
 
#29 ·
Does anyone have an idea what year model the new style filter was oem equipment? I would prefer to order one of those...whether I buy new or used. AND, what year did the pumps become non compatible with earlier 420's; 2014?
 
#30 ·
I would get a new pump if all you have is a china pump and the old one is already taken out.


No idea what year the filter changed, but the new style superceded the old style, so unless someone has an old one left over on the shelf and you specify the old part number, anything you order will be the new style.


I just buy ethanol free gas. Cheaper and easier than additives.




https://www.pure-gas.org/
 
#31 · (Edited)
Power sports nation has a used pump available for pretty much every year. They are sold by year model. That's the reason I asked about compatibility. I don't know if a salvaged 2007 pump would have the upgrade. But, I agree with you;

I found a new OEM pump for about $15 more than the most expensive (newest) one from Power Sports Nation. Gonna go with that one. Those PSN guys offer free shipping. Not Partzilla. Not unless I can come up with another $50 on the order. I'll check the relay.

I did get a replacement filter with the Chinese pump; in fact, 2. One each for the original horizontal and the new vertical positions. They appear pretty good quality. This fact made risking $18 on the Chinese pump palatable.

My station is a resource for real fuel. It's on the data base. I buy the cheap stuff for all my non street-able gas consumers. It's all corn enriched. Star tron has kept my vintage/carbed motorcycles and lawn/power equipment happy for years. NO E FREE FUEL in WNC when i lived there. Even the good stuff turns on you eventually. Maybe its possible I forgot the star-tron last year.
 
#32 · (Edited)
Well, this changes everything!

Egg on face... BIG TIME!

If a guy is going to use jumper cables, he ought to make sure the amps and ohms can travel from one end to the other...unimpeded! Something made me think to test them. My decades old positive jumper couldn't pass current. And I had used it to pass judgement on components.

I made up some new cables and retested the things I had intended (and failed) to run 12 volts to. Here are those results;

Relay has continuity to both the engine stop side and the fuel pump side. ='s good IMHO.

Fuel Pumps: OEM pump still doesn't respond to electro-shock. ='s DEAD! Chinese Ebay $18.00 pump Spins right up. Glad I figured this out before spending $90.00 at Partzilla for something I don't need.

I drained the tank of old fuel. It didn't smell too terribly off. Here's my plan:

I'm going to remove the tank and put some bb's inside and give it a vigorous shaking. I know there is no rust in there but I bought this rancher used 5 years back. It just seems prudent to take this precaution to loosen any crud that might have settled and stuck to the plastic innards before plugging everything back up.

The $18 pump is going to get a chance to redeem itself after I maligned it in this thread. I am going to go back and edit in a correction on those posts for others who might be chasing FI issues. Anyhow, I'll reassemble the pump and give it a try. Hopefully the pump is the only culprit in this crime.

One last question; Do you think I need new green fuel line connectors? These appear good to go another round. If your opinion is replace regardless, The Honda stuff (need to order) is the same as the NAPA parts (in stock) I assume?
 
#33 · (Edited)
Clean and Reassembly

I'm finished cleaning components and on my way to a running rancher.

But wait!

I know...I should have taken a picture! I'm ashamed that I did not. Not too ashamed to ask for help, apparently.

Before Giving Up On Pristine;

Image


After Cleaning: and beginning to reassemble; and realizing I'm not sure about the terminal pins' (bottom of the pic) polarity.

I know the lower (top of pic) @-the-pump-connection is correct. But, can anyone tell me if I have the positive and negative correct at those pin like connectors at the top of the housing (bottom right of the pic)?

EDIT: I think the positive and negative are reversed here. Wrong pic. I have the positive mating to the brown pin terminal on the p2 terminal atop the pump housing. Is that correct?

Image


EDIT Wiring is finished. Pump whirs with enthusiasm. I'm going to auto parts store in the morning for those green clips we aren't supposed to reuse. I'll be surprised if it doesn't light off at the slightest touch of the starter. Good news is, the forum wont have to suffer through this thread any longer.

My fingers are crossed for you.
 
#34 · (Edited)
Forget the auto parts stores; the green clips at O'reillys and Auto Zone are the same style but they do not have the size Honda uses on our FI system.

A 40 mile round trip to the Honda shop produced what I needed;

BTW, I hate Green Clips!