No power

862 Views 39 Replies 9 Participants Last post by GDCobra, 15 d ago

miata76

Discussion Starter · 1 mo ago

2003 SV1000 OEM Naked.
Engine starts fine.
Won’t reach 60mph. Will only reach 55mph in 5th gear (not 6th)
Limited power below 3,000 rpm. No power above 3,000 rpm.
Fuel flow was a bit low (8oz after three prime cycles).

Bypassed embedded fuel filter via 45 degree angle drilling of pump assembly. Installed 10 micron inline filter between pump & throttle bodies. No improvement in power.

Replaced fuel pump & fuel pressure regulator. Now three prime cycles produce closer to 15oz of fuel (post filter). No improvement in power.

Trying hard to remove fuel rail - proving difficult (soaking in penetrating oil). Any ideas as to the best way to remove fuel rail screws?

If fuel injectors are bad, is there a rationally priced replacement?

Does the group think I’m on the right path?

Any other ideas?

Thanks!

1 - 20 of 40 Posts

Missing Link

· #2 · 1 mo ago

The rail screws are a B+t$h first ime....change them for allen heads.... Make sure you have a JIS screwdriver, and tap the end of the screwdriver with a hammer while you have tension
on the screw......an impact driver may help, but, push hard.
The injectors are quite probably gummy....get thme professionally cleaned...they are proabably squirting more than spraying

Reactions: 1

miata76

Discussion Starter · #3 · 1 mo ago

Missing Link said:
The rail screws are a B+t$h first ime....change them for allen heads.... Make sure you have a JIS screwdriver, and tap the end of the screwdriver with a hammer while you have tension
on the screw......an impact driver may help, but, push hard.
The injectors are quite probably gummy....get thme professionally cleaned...they are proabably squirting more than spraying

Professionally Cleaned: Who does that? For what sort of firm should I be searching? Thanks!

Missing Link

· #4 · 1 mo ago

Just a fuel injection specialist. They will be able to set up a rig to ultrasonic clean them....easy peasy

miata76

Discussion Starter · #5 · 1 mo ago

Thanks for the feedback!

No joy regarding “fuel injection specialists” in my area (Daytona Beach). I’m not certain if I am asking the wrong questions or what. The only response I get is “what year is your vehicle & we’ll get new injectors on order”.

Removed injectors & found bits of the high pressure filter media in the injector screens. I think the OEM filter broke down before I did the inline filter workaround. Bottom line: I THINK the injectors might be toast as they are clogged w/filter media.

I found a fuel injector cleaner with the worst working label (MEK, naphtha, isopropanol , etc.) & poured the whole bottle (for 15gal) into two gallons of fuel. Idle popped up 200 rpm & ran it at highest speeds I could attain (60mph) for about 30 minutes to be certain the cleaner is IN the injectors. It now has a bit more power, but still bad. I will let that steep overnight & see what, if anything, shakes out tomorrow. I’m not hopeful.

I think I remember reading that some version of a Subaru WRX injector will fit/work in these bikes. Does anyone have any insight (year, version, etc.)? Suzuki OEM injectors cost more than the bike is worth. It’s either new, workaround injectors or hope a “universal rebuild kit” will fit & along with a “poor man’s” injector cleaner apparatus ($10 Amazon) will do the trick. If that fails, the bike must be sold for parts .

Any insight regarding the above choices would be greatly appreciated!

See less See more

Reactions: 1

miata76

Discussion Starter · #6 · 1 mo ago

MY WORD!! I am not certain if I was tired, frustrated or both; however, I found “refurbished” fuel injectors purportedly for the SV1000 on eBay for only $32 for the PAIR (not the $400/each ($800/pair) I’d seen earlier when I crafted the prior post). I have ordered a set and will report back my findings once they are installed and impact vetted.

Again, thank you for your help!

Reactions: 1

Missing Link

· #7 · 1 mo ago

Years ago, i made up a rig with a can of carby cleaner and ran a hose to the unisntalled injectors, one at a time, and exicted the injectors with a 6v battery charger (not 12v)
did that over and over for a a minute or two, then dropped them in a ultrasonic bath with straight fuel injector cleaner for several hours, then repeated....i could notice a visual
difference in the spray pattern for sure....much finer...then then bike did run a much nicer.
So, when you get refurbed injectors, keep looking for a fuel injector guy and get them done and keep as spares.

Reactions: 2

estevns

· #8 · 1 mo ago

Missing Link said:
Years ago, i made up a rig with a can of carby cleaner and ran a hose to the unisntalled injectors, one at a time, and exicted the injectors with a 6v battery charger (not 12v)
did that over and over for a a minute or two, then dropped them in a ultrasonic bath with straight fuel injector cleaner for several hours, then repeated....i could notice a visual
difference in the spray pattern for sure....much finer...then then bike did run a much nicer.
So, when you get refurbed injectors, keep looking for a fuel injector guy and get them done and keep as spares.

How come you supplied them with 6v and not 12v?
A little lazy and haven't checked the workshop manual - do they also get 6v from the ECU?

Missing Link

· #9 · 1 mo ago

estevns said:
How come you supplied them with 6v and not 12v?
A little lazy and haven't checked the workshop manual - do they also get 6v from the ECU?

Its about 5v, so i was going the high power version with 6v.... ha ha

Reactions: 1

estevns

· #10 · 1 mo ago

Missing Link said:
Its about 5v, so i was going the high power version with 6v.... ha ha

Good to know! Maybe I should at some point try to blast mine out as you described. One thing is distance driven, the other is probably the amount of fuel been just siting there for all those years.

Urbanjugle

· #11 · 1 mo ago

miata76 said:
Professionally Cleaned: Who does that? For what sort of firm should I be searching? Thanks!

Check these guys, you can ship them your injectors.

www.injectorrx.com

Shipping Instructions

Shipping Instructions for your fuel Injector cleaning services. We clean and recondition your dirty, clogged fuel injector. Reliable and fast turn around.

www.injectorrx.com

Reactions: 1

miata76

Discussion Starter · #12 · 27 d ago

No Power Update.

After a couple of false starts I was able to source a pair of refurbished fuel injectors & have them installed. SLIGHT IMPROVEMENT. Motorcycle still lacks power to the point of dangerous (will get to 60mph in 6th gear, but no more). Power is low across the range, but it seriously drops off after 3,500 rpm.

Recap:
Fuel filter bypass & downstream inline filter
New fuel pump & regulator. System now flows 15oz fuel after 3 “primes”.
Two refurbished fuel injectors
Both cylinders are firing & exhaust pulses seem substantially similar between the two pipes.

Any ideas? I’m willing to cut the head off a live chicken at this point . . . Please, no matter how remote, seemingly absurd, etc., I want to hear your ideas; I’m at a loss regarding how to proceed.

I hope the bike is not “dead”, but that is looking more like the case with each successive fix’s failure.

See less See more

Missing Link

· #13 · 26 d ago

Have you made sure that damn regulator is fixed in place properly ? If its dislodged you will get good flow, but very little pressure.
Also, i assume you removed the fuel rail, as the injectors need that to be removed. It was clear ?

Looking back to your first post, we heard of the the bike having a problem....but, when did this issue present ?
Had you just bought it and thats the way it was, or, had you done some work that may have contributed ?

miata76

Discussion Starter · #14 · 26 d ago

ML - Thanks for your reply and continued interest.

Fuel Regulator - The plastic spring clip that that holds the regulator in place was fatigued & rather weak. I supplemented it with a quality zip tie with a metal “tongue”. That said, your point is a good one; I will pull the tank and verify its continued function. (Note: When the fuel line is disconnected, the tank “dribbles” fuel continually; is this normal?)

Fuel Line/Rail - The whole fuel path was tested and it is obstruction free. All fuel flow tests were done downstream of the inline fuel filter to verify the filter did not produce an obstruction. All fuel lines are “newish” (less than two years old) and fuel rail was tested when the injectors were initially inspected and again when the injectors were replaced.

No Power Presentation - I’ve had the bike about 6 or 7 years and it has been “dead reliable” that whole time. It was severely neglected prior so I changed out the bearings, rebuilt the brake calipers, overhauled the forks, etc. I did the “green connector bypass” early on (relay). Work done since it just the basic maintenance stuff (brake pads, replaced the leaking master cylinders as it was cheaper than a rebuild kit, swap out coolant and brake fluid every two years — humid coastal Florida).

Several months back the motorcycle seemed down on power (down over the course of several months). These symptoms seemed to point to the fuel pump housing integrated fuel filter so it was then I performed the integrated filter bypass. Since then I have been “chasing it” as has been reflected.

By The Way - For anyone trying to remove the fuel rail screws or something similar, this tool worked a treat. I purchased it a while back to remove the fuel tanks from an old Piper Cherokee. It worked well in both cases. It requires a rivet gun (solid rivets) to function; the vibration combined with a back and forth motion on the screw breaks the adhesion and the screws come right out. Tool is “low tech”. The arm seen in the photo is used to turn the screw (unlike an impact driver) - the rivet gun only produces the vibration.

Product Azure Rectangle Font Screenshot

I hope this helps someone.

Product Azure Rectangle Font Screenshot

See less See more

Missing Link

· #15 · 26 d ago

The fuel dribble "should" only continue until the fuel line and inline filter drain, i was pinching the hose to stop the dribble, thinking that the bypass
had caused it to keep running, but, no, my tank is on my now dead bike with the line hanging and it hasn't run.

Not sure if you have the facility, but a leak down test / comp test is probably your next port of call.

Oh, do you have a Power Commander or similar on it ? If so, bypass it, just unplug it and plug the bike back into itself and test.

GDCobra

· #16 · 25 d ago

Missing Link said:
The fuel dribble "should" only continue until the fuel line and inline filter drain, i was pinching the hose to stop the dribble, thinking that the bypass
had caused it to keep running, but, no, my tank is on my now dead bike with the line hanging and it hasn't run.

Not sure if you have the facility, but a leak down test / comp test is probably your next port of call.

Oh, do you have a Power Commander or similar on it ? If so, bypass it, just unplug it and plug the bike back into itself and test.

I'm a bit late on this one and you beat me to it ML. Compression test at least, leak down even better. I'd also test the fuel pressue directly rather than simply testing that everything 'looks right'. If fuel is good and compression is good that should only leave one thing.

miata76

Discussion Starter · #17 · 25 d ago

Thanks for all of the input. You’re both right; a leak down test is likely in order.

ML’s “What have you done . . .” question caused me to REALLY think. There was nothing that I had done RECENTLY . . . However, shortly after purchasing the bike, the clutch switch (that grounds the clutch sense wire when the clutch is pulled), unbeknownst to me, disintegrated. As a result, the sense wire was always grounded. The bike would start, but it was running on the wrong fuel MAP, quickly fouled a plug and ran on one cylinder. There was no “fixing” the switch, so I replaced it with a relay that was triggered by the starter circuit. When the rider hit the start button, the relay would close, ground the clutch wire and the bike would start. Once start button was released, the relay would open and the bike would revert to the correct fuel MAP. This worked flawlessly for years. It never occurred to me that this could be the culprit since the bike ran, while poorly, significantly better than it ran with the clutch sense wire grounded.

Upon testing the relay, I found there was significant leakage across the contacts when the relay was open (a very low OHM reading). There was not, technically, continuity, but there apparently was, apparently, enough of a connection to confuse the bike’s computer. To prove the concept, I removed the relay and replaced it with a momentary switch dangled out the side of the bike. The bike runs MUCH better now. It is still down on power (carbon on the valves? computer re-learn? . . . ), but it is running significantly better and it is no longer “dangerously low” on power.

I will rewire the clutch sense wire to the newish clutch master cylinder, run copious amounts of fuel system cleaner to wash out the carbon build up and see how much of the power I can recover. After the system is cleaned a leak down test is likely in order to see what else might be afoot. The bike lived a very hard life before I purchased it (for next to nothing) and all of that could be “catching up” to it.

Thank you for all of your insight and insightful questions!

By The Way - There is no “Power Commander”, but that was the right path. Great question!

See less See more

Missing Link

· #18 · 25 d ago

Sounds awesome that you have found part of the solution. By clutch sense, i assume you mean the little switch under the clutch master cylinder ? Might be worth getting a new one, its better than adding bits and pieces, which as you have found, can go wrong.
Another thing that happened to my bike ages ago, was it would break down, or lose power over 6k rpm, couldn't find the issue, until i read a post in another forum, on a different bike, where the sidestand switch became faulty, and vibes from the revs causing it to carry on a treat. I disconnected it under the tank and bridged the "engine" side of the connector. no more issue.

GDCobra

· #19 · 25 d ago

Great news, good to hear of another SV heading back to full health and another SV owner heading back to full happiness! Gotta love that feeling when you solve a problem.

BTW, I'm judging by your monika that you have some association with the wonderful Mazda car? Which model do you have/had?

miata76

Discussion Starter · #20 · 25 d ago

Missing Link said:
Sounds awesome that you have found part of the solution. By clutch sense, i assume you mean the little switch under the clutch master cylinder ? Might be worth getting a new one, its better than adding bits and pieces, which as you have found, can go wrong.
Another thing that happened to my bike ages ago, was it would break down, or lose power over 6k rpm, couldn't find the issue, until i read a post in another forum, on a different bike, where the sidestand switch became faulty, and vibes from the revs causing it to carry on a treat. I disconnected it under the tank and bridged the "engine" side of the connector. no more issue.

Side stand: I, too, had the dreaded “side stand issue” & just eliminated the switch (soldered the wires together) so the bike thinks the stand is always “up”. To use your term: easy peasy. 😉

Clutch switch: The recently installed new clutch master cylinder has a switch; I just never used it due to my prior, ingenious workaround 🤦‍♂️. I will expose the old wiring & get the switch hooked up post haste. The current set up precludes the rider from engaging the clutch during start up - not good.

Thanks for everything & best of luck on your part out.

Reactions: 1

1 - 20 of 40 Posts