Should i replace all injectors even though they test the same as my new ones. my car was bogging at 2200 rpm,s the shop told me new injectors, took manifold off, tested old injectors. I am not getting a code for a misfire but it is misfiring, not the Maf, not the coils or plugs. what else can it be, can the o2 sensors cause this??

 

.... all motor forum....

 

did you check your spark plugs, do you have any oil on them? If so... Maybe leaking piston rings??

 

Or bad valve cover gaskets and plug O seals.

 

i just got a new engine put in from a junkyard, and did notice oil when i was changing a plug, tell me more about he piston ring please

 

So the engine is not new since its from a junk yard. You can't be too sure about getting something like an engine or a transmission from a junk yard. It's a big gamble to do that.

 

but this should not happen at 40k, also i do have a warranty, 2 years on the engine, will call them this morning.

 

There are seals on the inside of the valve cover (for each valve cover) - that seal the spark plug tubes from the valve covers... this is the seal that cracks over time and allows oil to escape from the valve cover into the spark plug chamber (as you have noticed). You need to pull the valve cover and replace those seals. Replace the main valve cover seal too. Since you already have the plenum off, this should be easy and may be worthwhile to do on both the front and rear valve covers.

Typically bogging at around the 2000RPM mark indicates a bad MAF. You claim that it is not a bad MAF - how did you come to this conclusion?

If the engine is under warranty, why are you doing the repair work for the injectors. What exactly does the warranty cover?

 

that is true, bogging around 2000rpms usually means a bad MAF. disconnect your maf sensor, your computer will compensate for it. see if the problem returns.

 

i used a maf from my girfriends maxima, as well as the junkyard one, same results, not sure if the bogging is at 2200 consistently, more or less when i press the pedal 1/4 of the way down in any gear, (i have an automatic).

 

My garuntee covers the long block, block and heads.
Fuel injection, manifolds, oil pan, timeing belts, and covers, wire harness, oil leaks are not. but this is a leak in the internals of the engine, which was there since i purchased the engine, and should be covered.