3.0L Auto won't rev...

[MeanM60]

Hey guys, I'm new here, but not new to mechanical repairs/diagnosis.

I have a 2004 Ranger 3.0L Auto 2wd that I replaced the engine in recently. Upon getting it all back together, I started the truck. Started fine, idles great, no CEL. Revs in P/N until the P/N rev limiter is reached at about 3k. Good. Upon driving it, I started to hear a metal scraping sound...definitely rotational, down by the bellhousing/flexplate/tq converter area. I thought to myself that it was the dust sheild between the block and bellhousing...because I put a very slight bend in it so it would have a little tension and stay on the pegs while I mated the trans and motor up by myself.

Now the issue: when driving, the truck is GREAT until about 3000-3500rpm, where it really loses steam and won't rev higher. No, it is not the P/N switch, as it's not a 'rev limiter'...it just happens to lose power in a similar spot on the rpm range. There are no CELs/codes stored, looking at live data in the scanner results in everything reading out as it should (of course...thus no CEL) The engine load reads high, but that seems to be a Ford thing from what I have been reading. So I have checked all sensors, plugs, wires, cleaned the MAF, replaced the fuel filter...all thinking it was an engine issue. So today, I jacked up the rear end and put it in drive...and it revs freely through all RPMs. So my issue seems to be only under load.

I'm stumped. The only thing I can think is that I had a bit of a hard time with the tq converter, and tried to mate the block/bellhousing only to find I needed the TQ converter to go one more click back...I did not put a lot of power on the wrench trying to force it...once I realized I needed to seat the TQ converter better, I did so and all went together great. My worry now is that I did something to the trans when I tried to bolt together the first time. All gears are present, and no delay going into gears or anything. Shifts are smooth.

What do yall think?

TL;DR--truck stops revving at 3000rpm, it's not the P/N limiter or switch, truck runs great and no CELs.

I appreciate the help!

Tyler

 

[MeanM60]

Also, just checked vac with a gauge...idles at 17 which is obviously on the low side...upon revs, it goes to almost 0. Needle is steady.

 

[MeanM60]

Well, thank you guys...I know nobody posted, but doing some digging/diag...one of my cats is twice the temp of the other one...I assume I have a bad cat. Figured this out with help from TRS...so I appreciate the help!

 

[RonD]

I was going to suggest checking for clogged exhaust

You can do that with a vacuum gauge