Huge Power Loss! Need Help...

[SofaKingWeToddDid]

it sticks out on the passenger side from the fuel injector cover (the DOHC plaque on the motor)... the thing that looks like a bigger tire filler? lol im pretty sure thats what it is.

[Danspeed1]

i don't know where the schrader valve is on a 3.4 fuel rail... but that is where you would test fuel pressure...

the "rust" color alone is normal. are there any deposits built up on it anywhere and what color are they? and are the electrodes looking completely normal or are they looking somewhat melted, or chipped or do they have little specks of metal on them?

is the rust color consistent all the way up the insulator?

No deposit build ups, electrodes look new with a light rust color coating.

DG

[robertisaar]

then those are fine. change them if you want, but they still have a lot of life left...

EDIT: from bruce plecan (grumpy from TGO... RIP)

White leaning to beige Good WOT mixture

White leaning toward black Momentary rich spot

Bonding agent cooked out between porcelain and center electrode, or the side electrode gets a metallic green/blue hue Plug range too hot, or temp too high in combustion chamber, possibly too much timing

Heavy black flakey deposits Too much fuel

Black glossy deposits Oil

salt and pepper flecks/fly turds/tiny metallic balls on porcelain Detonation. The flecks are little bits of piston

Fire ring (tan spot/ring) If high up on porcelain timing is probably good. If it's near the tip you might want to try a little more timing

Corners rounded off center electrode (newish plugs) lean/too much timing. Or just normal wear if the plugs are old

Black spiderweb traces on center electrode Usually only on early HEI systems, a better spark box or maybe low resistance center button will fix it.

Pools/spots of odd colors Fuel splashing, fuel additives. Can vary with brand. Manganese leavs a pink residue which can be a ground path and cause misfires.

[Danspeed1]

Just did a fuel pressure test.... 40 PSI at Idle and 48 PSI under load

Seems about right to me. So I think its safe to say the fuel filer and pump is good.

I am wondering if the injectors could be bad.... OR because the fuel pressure did not bleed off and the plugs look tip top,... the injectors are good...

I am stumped!

Dan

[robertisaar]

since when you unplugged the MAF and had no change, i would say thats your issue...

[Danspeed1]

Could a bad knock sensor cause this problem?

Where is the knock sensor located on this vehicle?

Dan

[94GPGTP]

What brand plugs are in there? If Bosch get em out asap!! Put AcDelco in there. I fouled 3 plugs at once and they were Bosch. Bosch does not make a good plug for the W platform. That could be your problem right there.

[Danspeed1]

I always run Acdelco's

DG

[timg]

I'd go with the FPR or the MAF sensor being the problem. I've actually had a problem that was VERY similar before (and very annoying), but I don't remember exactly what was wrong. The FPR can fail and begin leaking fuel into the intake manifold. Normally, it causes hard starting, but once the car is running everything is okay. IIRC, when I had MAF problems they were similar to what you are describing.

Tim

[Danspeed1]

Replaced all the coil packs... ($75) no difference.

Is this a possible injector problem?

I unplugged the maf... no difference

Dan

[robertisaar]

if you unplug the MAF and nothing changes, what does that tell you?

[pocket-rocket]

if you unplug the MAF and nothing changes, what does that tell you?

And I'm not even a MAF or OBD2 guy.

[robertisaar]

And I'm not even a MAF or OBD2 guy.

neither am i i hate the both of them. i just know that if you unplug something, and nothing changes, it wasn't working correctly, if at all, in the first place...

[pocket-rocket]

neither am i i hate the both of them. i just know that if you unplug something, and nothing changes, it wasn't working correctly, if at all, in the first place...

That's what I've always believed too

[Danspeed1]

Wait a second though... Won't the MAF resort back to the base tables when unplugged? Lets say the car is running correctly... if I unplugged the MAF it should run slightly worse, but it should still run.

Now if the maf was working improperly, when I unplugged it, the car would resort back to the preset base tables, and should run better, but not great.

Am I on the right track here... or are we facing an MAF problem?

Dan