no power up top

[Murphy]

92 spirit 3.0 v6 543

The engine is really loosing power up top. If I floor it, the engine will get to about 4000-5000 RPM and just stop depending on the gear/load. in neutral or 1st gear I can hit the red line. I think my cams might be advanced. When looking at the timing mark on the pulley, is TDC in the center of the circle? Mine is a few degrees off from the circle...

I was having this problem before my recent timing belt change, but it would happen at about 5500 RPM in 3rd gear, and it wouldn't always do it.

Is there anyplace else I should look aside from cam timing? What else would cause the ecu to pull ignition timing?

[raccoon]

knock maybe, bad injector. fuel pressure.

[Sundance 6g72]

from ED's site

Contrary to what you may have read elsewhere or considered, you will not eek out high end performance or low end torque by setting the cam a full tooth off in either direction. 1 tooth equates to about 9 degrees. To fine tune the power band, you would want to adjust the timing +/- 5 degrees max. It is possible however based on the sprockets, and belt you are using for the marks to be a small fraction of a tooth off. Just make sure it is as close as possible.

[RoadWarrior222]

If timing is good enough, list of suspects should include, MAP, TPS, fuel filter and/or pump.... though I also got some crap in the optical disk once that made it funky.

---------- Post added at 04:14 PM ---------- Previous post was at 04:13 PM ----------

Oh, clogged cat, loose muffler baffle, flattened exhaust can also be culprits.

[Murphy]

oh ya I forgot to run the codes. Next time I take it for a drive, I'll watch the A/F.

---------- Post added at 04:30 PM ---------- Previous post was at 04:28 PM ----------

Are there any options to go catless? Will a turbo DP work or would it be possible to 'test pipe' it?

[RoadWarrior222]

Well it should have a donut in a hemi joint before the cat, so if that doesn't seem too rusted up, you could unbolt it there for a test.... be friggin loud though.

[turbovanman²]

I would vote on plugged cat or fuel system issue, IE bad pump or plugged fuel filter.

Hook a vacuum gauge up to the intake, manifold vacuum, note readings, go for a drive, if you WOT it and experience pressure in the intake, you have a plugged exhaust system.

[Sundance 6g72]

oh ya I forgot to run the codes. Next time I take it for a drive, I'll watch the A/F.

---------- Post added at 04:30 PM ---------- Previous post was at 04:28 PM ----------

Are there any options to go catless? Will a turbo DP work or would it be possible to 'test pipe' it?

turbo downpipe? wouldnt do you any good on a 3.0

when i ordered my fwd catback exhaust, i also had a magnaflow straight through muffler. i pulled the cat off and put the muffler in its place and then ran the exhaust off the muffler and it fit alright but not perfect. Im not a perfectionist so i called it good.

---------- Post added at 10:57 PM ---------- Previous post was at 10:53 PM ----------

not sure if this is practical or even the right thing to do. Disconnect the exhaust at the manifold and go for a quick drive. This is if you cant check the exhaust the correct way shown above ^ ^

[Ondonti]

disconnect and test, sure. Not gonna kill you.

[Murphy]

Just checked the cam timing, looks bang on. I thought it was off before because I thought the timing marks on the crank were 2* each.

codes: 12,15,55 15 is the SDS because i dont have it connected to the ECU right now.

A/F - when it hits the wall the A/F sits at full rich and drops off and comes back about once a second

I haven't checked the cat yet

[Murphy]

I put a boost gauge on the intake and took it for a drive. The car wanted to act normal today and I was able to redline 3rd without a problem.

[RoadWarrior222]

Mouse nests in the intake

[Murphy]

I was wondering if there was something weird with my intake, I have a CAI on it, maybe I'll take it off, make sure its clean and try a different filter

[turbovanman²]

.

A/F - when it hits the wall the A/F sits at full rich and drops off and comes back about once a second

I haven't checked the cat yet

That's normal, they go pig rich at WOT.

Just for shitt's and giggles, check your fuel pressure.

[Murphy]

took it out again, it was hitting a wall a 4-5k again. The boost gauge didn't go above 0.

guess i'll check the FP. I put the pump in less than 2 years ago and i was reading 55 psi

[Murphy]

FP is 54psi with the vac line off. I don't think I can keep it hooked up while i'm driving...

[turbovanman²]

took it out again, it was hitting a wall a 4-5k again. The boost gauge didn't go above 0.

guess i'll check the FP. I put the pump in less than 2 years ago and i was reading 55 psi

Its supposed to be at 43 psi. 55 is for a turbo 4 cylinder. No wonder its falling on its face, its just too rich.

[Murphy]

I also have a MSD SCI box with a blaster 2 coil, what are the chances that that would be causing the problem?

[turbovanman²]

I also have a MSD SCI box with a blaster 2 coil, what are the chances that that would be causing the problem?

It could be see post 17.

[Murphy]

its been at 54 psi for about 2 years now and it hasn't started causing a problem until a couple weeks ago. How can I fix this? new FP regulator?

---------- Post added at 04:30 PM ---------- Previous post was at 04:25 PM ----------

According to the FSM stock is 48. Still high but 7 is a bit closer than 12.