Sei fuel injection

[thrasherg]

Okay guys, I have my friends trike back together, all the electrics work as Honda intended, the engine starts and idles beautifully, but it will not respond to the throttle, as you open the throttle the revs start to rise and then just drop and the engine stalls. It will start up immediately and idle but will not rev up.
I suspect this is either due to the injectors not operating correctly (bike has been sat for a few years unused) or maybe the ECU is misbehaving(bad sensors or something). I don’t have any error lights, but I wondered if there are any error codes and how you read them? Failing that, if it’s the injectors, is there any company that has a good reputation for servicing and rebuilding them? I have not removed them from the engine yet, but I suspect they are not meant to be taken apart and rebuild by a home mechanic? Any suggestions, I have kept the cost of parts to $200 so far and don’t want to spend a fortune on this last issue, it’s the only thing preventing the bike from being ridden.

All suggestion are gratefully received. I am very familiar with carburetors but have not worked on fuel injection systems, so am open to all suggestions. The bike has done 56k miles, compression is good and the engine seems in great. Condition just this refusal to rev up is preventing it from being used.

Regards Gary

[Phunnybone]

I haven't needed to use them yet, but I picked up a set of 4 remanufactured injectors off eBay https://www.ebay.com/itm/4-OEM-Fuel-Inj ... 3af62b7f15 for less than $50. They're actually off a Honda Prelude (my LTDs are 1985, but I believe the parts are interchangeable with the '86 SEIs).

One caution - save the O-rings from old injectors. From what I've read, the O-rings from the Prelude injectors are just a little smaller than the ones needed for the Goldwing.

[twocams]

How is the fuel pump delivery. So much gas in so many min. or do you have the right fuel pressure. In PSI

twocams

[thrasherg]

The owner had a new fuel pump fitted a few weeks ago, so it should be good, it certainly sprays fuel very well when I crack any of the banjo bolts on the fuel line, but I don't have a gauge to check fuel pressure (I assume you cant use a regular tyre pressure gauge, and I don't know what pressure the system, is meant to be running!! a distinct lack of info on my part.. I would prefer to take it to a garage that knows what they are doing, but I don't think anyone will touch a 31 year old motorbike, so trying to fix it for the owner, we are so close. If there is a cheap way to measure the fuel pressure I am open to try it, the fuel pump starts when the ignition turns on and it definitely pressurizes the fuel system, but I don't know what pressure the regulator is setting the system to. I feel I am at the try it and see stage!! Try changing the injectors, if that doesn't work then try changing the fuel regulator, the pump is new so wont change that, after that the ECU is the only thing that can be changed (plus it's sensors, but that is going to be expensive) hence my request to know if there is a way to read any error codes!! Of course if anyone can recommend a company near Dallas that deals with 30 year old FI systems I am happy to take it to them and get a quote and let them try to fix it, everything else is good.

[Rednaxs60]

Here's the full post:
Fuel pressure with key on bike not started - 34 to 38 PSI
Fuel pressure bike started - 28 to 34 PSI

Not much can be done to the OEM injectors except having them cleaned and flow tested.

As Phunnybone mentions, car injectors work just fine. I have installed and used Autoline 16313, worked well. Had the original injectors cleaned and flow tested, not a lot of difference before and after. If the system has been maintained, the OEM injectors are very resilient. Others have used SMP FJ267 injectors as well. If the bike starts but will not rev, the injectors are probably not the problem.

No error codes on the ECU under the rear trunk so the inputs from the various sensors is adequate for the system to operate. You mention a new fuel pump was installed. What is it from and you need to know the pressure range. The fuel pressure regulator is quite basic. No new ones available. Can you post a picture of the new fuel pump and provide some info on it?

Hope this helps.

[thrasherg]

Thanks for all the replies, as the engine idles beautifully I figured the injectors must work, but as it won’t rev up I figured they where maybe not flowing enough gas. The fuel pump was installed by a garage, so I will dig out some info and post the details. Is there a low cost way to measure the pressure of the fuel rail? Now that you have told me the correct pressure range I would like to check it.

Gary

[thrasherg]

The owner just told me that when the new pump was fitted, the bike ran great for a few days and then started running badly! This was news to me as I had understood it hadn’t run correctly since they resurrected it a few months ago. This new news would really seem to confirm what others have said, it’s not the injectors but a lack of fuel, probably due to a bad regulator or maybe the pump has gone bad, either way I will now four on the pump and fuel rail to see if I can find the issue. Still hoping I can find a cheap way to measure the fuel rail pressure.

Gary

[DenverWinger]

Is there a chance the branny-new fuel pump sucked something out of the fuel tank on a bike that had been sitting a few years and pushed it into the fuel filter, restricting the filter enough to allow a smooth idle, but not enuf fuel to rev it up?

[thrasherg]

Now that I understand it did work correctly for a few days, I am thinking the exact same thing, I fitted a new filter so that is not blocked, but I suspect there might be a fine filter on the inlet side of the pump that is blocked with crap from the tank. Hope to check this week.

Regards Gary

[Rednaxs60]

There should be a fine cone shape filter in the fuel pump inlet. If there is crud in the tank, and probably is, it will block this small filter quickly. Had a lot of crud in my tank after some 34 years. There was rust - not as much as I thought there might be (took tank out and cleaned it), but before this, took out the fuel tank sending unit and I was able to vacuum and wash out the soft crud that had accumulated.

[thrasherg]

Well I got it fixed, unfortunately it was due to an incompetent mechanic, when the owner had a mechanic install the new pump, the mechanic used the wrong fittings on the output of the pump and effectively blocked the outlet so no fuel could flow, it was a wonder the bike even started. I changed the fittings and it fires right up and responds beautifully to the throttle. Took it for a short 2 mile test rides and it shot to 70 mph without any problems, runs great.. the owner can’t wait to collect it. Thanks for all the suggestions and ideas that everyone provided.

Gary