Injector Problems

[comfortably numb racing]

Help me Mr. Wizard! Having issues with my fuel injectors. I am currently trying to convert to a Honda and am having issues getting the injectors to work. The motor spins at 250rpm, we have 50-60 lbs of fuel pressure, the engine fires if starting fluid is used, the injectors have a constant 12 volts and the ECU light shows no issues, Any suggestions would be appreciated. Thanks!

[mikey]

need more info here. are the injectors new or old? if old, they may be gummed up and unable to "fire". have you bench tested the injectors?

If you start the motor with starting fluid, does it then continue running? If yes, then your 250rpm by itself may not be enough to start without fluid.

[comfortably numb racing]

need more info here. are the injectors new or old? if old, they may be gummed up and unable to "fire". have you bench tested the injectors?

If you start the motor with starting fluid, does it then continue running? If yes, then your 250rpm by itself may not be enough to start without fluid.

Thanks for the reply.
yes the motor is slightly used , I am old school never bench tested an ejector , thanks Ill try it.
and no the motor only fires on starting fluid but doesn't continue to run.

[Raceworks]

Is the engine wiring harness new? If not, pull it & check for breaks. Use a continuity tester. Do the same with the cabin harness.

You need to make sure you're getting at least 12 volts while it's cranking regardless of the RPM, otherwise they act weird.

Double check the engine grounds. There should be two: one on the head (near the rear) and one on the block (I usually attach it to the bolts that holds the timing chain cover on).

Check for blockages between the fuel pressure sensor & the fuel injectors. I've had times where they read good pressure but there's very little to no fuel to the rail (usually a clogged filter). If you don't have a fuel filter get one.

If you don't have the fault light hooked up, do so & see if it's flashing any codes.

Stop using starting fluid. It's a good way to ruin any engine made after 1975.

EDIT: It may not even be fuel injectors. Check for vacuum leaks: injector o-rings, the blanking plate for the EGR valve, and the MAP & IAT sensors on the manifold.

[Will Velkoff]

Sam's post made me remember another thread from back in the fall. Read through this one, especially Greg Rice's post

https://www.apexspeed.com/forums/sho...iagnostic-help

[problemchild]

In my 11 years around the FIT race engines, I have seen many people changes injectors, in some desperate attempt to fix a problem they cannot otherwise fix. It only fixed the problem once, and in an exercise of the inept leading the blind, I believe they fixed the actual problem in the process of changing the injectors. Just sayin .....

[comfortably numb racing]

In my 11 years around the FIT race engines, I have seen many people changes injectors, in some desperate attempt to fix a problem they cannot otherwise fix. It only fixed the problem once, and in an exercise of the inept leading the blind, I believe they fixed the actual problem in the process of changing the injectors. Just sayin .....

Thanks for every ones help I have leard a lot about trouble shooting the honda ,it came down to sticky injectors from a used motor that sat for 3 years.,
ethanol gas,I put in new ones and it fired up. Hope to see it on the track latter this summer ,

[cjsmith]

Something you may want to conciser, instead of throwing the bad injectors out. Send them out to one of the many shops that rebuild them. The cost in minimal, they rebuild and bench test them and send them in a sealed package, then you have fresh spares. I've used Berry Mumm, (mummbrothers.com). Much cheaper than buying new ones.

[comfortably numb racing]

Something you may want to conciser, instead of throwing the bad injectors out. Send them out to one of the many shops that rebuild them. The cost in minimal, they rebuild and bench test them and send them in a sealed package, then you have fresh spares. I've used Berry Mumm, (mummbrothers.com). Much cheaper than buying new ones.

Thanks Good idea.