Multiple misfires, injectors?

[cpstack]

I have a 2000 5.4 expedition with 215k miles. I recently began having a misfire on 3, 7 and 8. COPs are fairly new as well as plugs, I checked them anyway and they are good. Took continuity readings on the injectors, all are 16-17 except for the 3 that are misfiring. One is 0 and the other two are reading 500 and something. I know that this points to the injectors being the issue but before I tear in to replace them it just seems impossible that all 3 could go bad at once. Possibly a computer issue? Any help is greatly appreciated

 

[docraymund]

Check battery voltage first and alternator condition after that if you can, check fuel pressure. The fuel pump might be going bad.

 

[toms89]

I have a 2000 5.4 expedition with 215k miles. I recently began having a misfire on 3, 7 and 8. COPs are fairly new as well as plugs, I checked them anyway and they are good. Took continuity readings on the injectors, all are 16-17 except for the 3 that are misfiring. One is 0 and the other two are reading 500 and something. I know that this points to the injectors being the issue but before I tear in to replace them it just seems impossible that all 3 could go bad at once. Possibly a computer issue? Any help is greatly appreciated

If your readings are accurate it seems you do have 3 bad injectors. One shorted and two with basically open coils.

It does bring up the question as to why? Got me there.

May want to replace and closely monitor. Check voltage, fuel pressure, etc....

I believe the pcm switches the grounds so not sure how it can damage them unless they are stuck on.

 

[cpstack]

Haven't had the first hard start. Wouldn't that be a symptom if the fuel pump was involved?

 

[cpstack]

It's not my daily driver, it sits quite a bit. Others have suggested the ethanol gas sitting up in the rails plugging the injectors? The continuity readings would rule out plugged injectors though.

 

[toms89]

It's not my daily driver, it sits quite a bit. Others have suggested the ethanol gas sitting up in the rails plugging the injectors? The continuity readings would rule out plugged injectors though.

Maybe they overheated due to lack of fuel flow???

Just shooting in the dark though....