Injector advice

[airdrew99]

I just checked resistance in my glow plugs and my injectors (checked my injector resistance to the center pin on the valve cover plugs). Each of my glow plugs showed 0.9-1.0 ohms. Each of my injectors showed 3.4-3.6 ohms except my passenger side rear injector (Haynes manual says this is the #7 cylinder). I checked that one multiple times and it continued to read 10.4 ohms. So, that one is bad right? I've changed my glow plugs before and they were pretty easy to change and required no special tools. What about changing an injector? Any special tools required? Any harder to change than the glow plugs? Where is the best place to buy a single injector? The whole reason I checked all this in the first place is because my truck is taking a little longer to start when it is cold (first crank of the day and it has been in the 60s here). The engine is spinning over fast, but it is taking a few seconds longer to start. I have the Stancor relay (which is awesome) and it has less than 0.2V drop between posts. Thank you for all input.

Drew

 

[DaveBen]

Glow plugs should be 1 ohm, so you are good. I don't know about the injector change special tools. Your #7 injector looks out of spec. These engines can take a bit to fire off the first time. The HPOP (High Pressure Oil Pump) needs to get the oil pressure up to something like 500 pounds to fire off the injectors. The oil pressure can bleed down over time.

Dave

 

[airdrew99]

If an injector is reading 10+ ohms, does this just affect power? MPG? I'm assuming it is somewhat functional, just not optimum right? Thanks.

Drew

 

[CSIPSD]

What is leading you to check injectors?

Honestly you need to get some scanning software on there to do a cylinder contribution test, Buzz test and a KOER test. Checking for continuity is nice, but without knowing the history of the truck its not a test all to replace an injector.

Once you turn the truck off the HPO pressure drops to about 80-100psi in seconds, no pressure is maintained in the rails. You could have a leak down issue or have worn or cut injector O rings.

Get a scanner on it and check ICP pressures and duty cycle while cranking.