I have a 99 stock mini and on initial cold start up my engine spits and sputters then goes into a high idle, then drops to a really low idle, then picks back up to either a good idle speed or high idle again. After it is good and warm it seems like it is running just fine. Just started doing all this and I was wondering what anyone thought might be the problem? My thought is the fuel filter might be clogged or bad in some way... looked for it and couldn't find it anywhere so I'm assuming it is in the tank?
Is it a HA4 or HA5 ? HA4 has a external fuel filter that looks like this. If it's original it may be painted black but its mounted up by the fuel pump.
HA7 fuel filter is in the tank. Don't know much about the HA7 but I would assume since its fuel injected that it would have a fitting on the fuel rail to check the pressure. That's where I'd start.
Oldmachinist do you think the fuel filter might be the problem or any other suggestions? Or too little info... Thanks for the help
If the filter is clogged a fuel pressure test would likely show low pressure. But it could show good pressure until you rev it up and then the pressure may drop because it can't flow enough.
Just found a old thread that says the fuel pressure should be around 45psi. http://www.minitrucktalk.com/showthread.php?4065-Honda-HA7-Fuel-Pump-Pressure