new engine lacking power..?

I've been driving my truck around for a few months now with a brand new engine. 4cyl 2.7L 3rz 4wd 1997 extra cab. Most of the engine is new (6,000 miles on it) except for things like valve cover, throttle body, intake manifold, injectors, vapor canister and a few others. The only time i notice a lack of power really is when I'm going up a hill. i can feel it running fine and accelerating up until around 50 mph it will stop accelerating. each time it shifts around 2500 - 3000ish RPM and on the last shift it bogs down to a little under 2500 rpm and won't go any higher /very slowly gets higher until i either get over the top of the hill or it downshifts and revs up to like 3200-3400 rpms cause I'm pressing on the gas a little too hard.

Edit: before i changed the engine before this i had pretty much the same problem but a little less power cause the engine was blown.

 

I have found that the 3RZ has a really flat response in the 2300 RPM range. I had the same problem with my truck. I recently installed an LCE header for it and the flat spot is almost totally gone now.

 

Ah that's good to know, I've been considering getting a 01-04 oem headers/exhaust manifold.

Last time I checked the MAF it seemed fine, it was pretty recently replaced(probably a year old). I hope the engine isn't blown since its only a few Months old haha.

Thanks for the replies.

 

Great to hear that I'm not alone. Even a slight hill and my truck will wind down and lose rpms and speed if I try to climb at 2000-2400 rpm in 4th or 5th gear. I end up having to downshift to 3rd and run it at 3500+ rpm, unless I want to slow down below 50 mph.

Interesting to hear that the LCE header fixed this. I have the OEM mini-header on, but I still have the problem. Could an exhaust leak at the manifold/head or at the manifold/downpipe junction cause this?

 

Hmmm, mine does fine in 4th @ 2000 rpm going up the hills/ big bridge, just not 5th, it'll start laboring and drop off.

 

I know that feeling. In the 4cyl auto, I feel like it hits 2nd gear and then the rpms fall of the fuckin chart. I wondered the same thing, but chalked it up to #4bangerproblems.

 

must be all the added weight and tires contributing to the power loss too.

My old 2rz base model single cab had no issues climbing hills, It had an LCE header, Magnaflow 18 inch muffler on stock pipes and a form of deck plate done.

it hauled ass even with the AC on i could go from 65-85 in a few seconds in 5th

Ahhhh plus you're an automatic.. yikes. Those were known to be complete dogs compared to the 5 speed which mine was.

 

i just feel like i never used to have the problem before when i first bought the truck like 6 years ago.. (original engine..) but i was a new driver at that time and maybe i didn't really have the feel for the RPM's and shifting and stuff and i would always just rev it up high in a lower gear going up hills.. i just remember i would always drive pretty fast everywhere back in the day and i didn't have a problem w/ the engine doing it haha..

 

hmm yea I'm sure all the added weight has done something.. the tires are only 31's tho but yea still not official stock size..

EDIT: Two things that i think it could be are the vapor canister, and the fuel pump.
reason i think it could be the vapor canister is because I've read somewhere that if you "overfill" your gas tank at all even a tiny bit you ruin the vapor canister. i think it could be the fuel pump cause the company i work for just had a different vehicle with a sort of similar problem.

 

4 cylinder automatic problems dude. When I had my 2011 I was always downshifting and driving like a race car up steep grades, it was kinda fun actually. But, any truck will do this, even us V6 guys when you add weight to em. Heavy tires really change everything. With my 2011, I went from the stock 4 ply Dunlops to the same size tire with Goodyear silent armors, only 10 ply instead of 4 and that changed everything with the way the truck drove and accelerated because of the extra weight. It was well worth it though having a tire that I could drive down a gravel road with and not worry about punching a hole in. I had only had my 2011 for about a month when I popped the right rear tire on a gravel road, one tiny little pebble lodged between the treads was all it took. Needless to say those tires went bye-bye in a hurry. I live in Montana so 70% of my driving is on old dirt roads.

 

9 years boys! how time fly's.

found this thread searching for similar issues and looks like most of you guys have it too. in fact I have the same if not a bit worse of a gremlin but mine is intermittent! comes and goes some days i hop in and she's rippin than other days its like an old tired dog exactly as you all describe and i can hear pinging when the motor is lugging I've been chasing this issue for years. not to revive an old thread but here we go

truck started having odd hard starting and shaky idle at start up and over pressurizing and eating/barfing coolant in 2016 around 178k miles, eventually blew it all out the over flow on the way to work and overheated the motor warped the head and blew the head gasket...than replaced it to a rebuilt balance shaft delete and stage 1 cam from Yota1, should have solved all my problems right? nope same exact issue remained

since the swap...

it's had a Doug Thorley header for years that's always leaked at the y pipe...fixed that, and safety wired the bolts, now it'll never come loose again. also the Cat was clogged and rattling. fixed that. (no other leaks besides a rusty muffler left)

MAF was changed but did nothing....put in a mid grade one from Quest but i cant remember the name.

swapped the IAC valve with a Toyota OEM part to fix the coolant over pressurizing/idling issue. old valve was sticking and leaking coolant into the intake and causing the hard starts as it burned off the coolant...that only fixed the shitty idle when hot/and on start but coolant system still was over pressurizing.

changed the EGR valve with Toyota OEM part as a last resort before doing the head gasket and BAM fixed the coolant over pressure issue..

but still drives like a old wet dog 75% of the time. just cant get out of its own way even on flat ground, passing a car yeah right. and 3rd gear holy shit that's when I hear the pinging most and it gets worse load up the engine and heat it up

than other days just when I wanna drive this pile off a cliff it just wakes up and drives like a bat outa hell.

I have a Toyota OEM TPS to drop in this weekend.

other than that I'm thinking the transmission is messed up? shifting outa sequence. i have a 5 speed im swapping in this spring so well see on that too


in the mean time anyone else figure out there issue? any other ideas?

 

None of this is "normal". I recently installed a LCE header and I never had these issues before and the header didn't cause a dramatic change. A bit more low end torque but I would be looking into the volume of fuel delivery if low performance is suspected. But the headers don't really do anything if that is the only modification. The LCE ones are sweet though.

 

Do a leak-down and/or compression test and go from there.

 

I drove a 97 2.7l for years. It just don't like dem hills. it was a nice truck too, got it from my brother with 45k original garaged miles. It still didn't like hills.
intake mods sound interesting, probably worth a shot.
Or just do the right thing and pick up a yota with a 5vz-fe and problems solved forever! (joking! plz no hate from you 2/7l guys)

 

My 99 does ok because the origional owner had a BO7A rear end put it when new