Topic: What would cause a newly rebuilt 22RE to run rough between 3000 to 4000 RPM?

[dms1]

What would cause a newly rebuilt 22RE to run rough between 3000 to 4000 RPM?

I rebuilt the engine last year and the engine runs ok on the road and idles well, but I just noticed if I slowly raise the idle from 1000 to 4500 RPMS it starts to run real rough between 3000 and 4000 RPM, after 4000 RPM it appear to smooth out. I also am only getting about 15 MPG after the rebuild, I used to get about 19 MPG.

Thanks in advance

[dms1 [OP]]

I just wanted to add that the engine light does not come on and there are no codes, also the wires, plug, distributor etc are new from Toyota and I have checked all the grounds.

[*ROKTOY*]

Did you have the engine balanced?

[SolidAxle]

CHECK for missing grounds. mine did that when i was missing one on the engine. there is one that attaches to the intake plenum where both halves bolt together. one at the back of the engine, goes from the plate on the back of the head to the firewall. one beefy one from the bottom of the block to the batt. I'm pretty sure thats it. somone will chime in if i missed one.

also try adjusting your tps.
 http://4crawler.com/4x4/CheapTricks/TPS/index.shtml

[brainlessfool]

Did you have the engine balanced?

X2 

[Larryb]

Try disconnecting the EGR valve and see if it makes a difference

[dms1 [OP]]

The engine was a new short block from Toyota - so I think it was balanced. I have checked all of the grounds and even added one, I will check the EGR valve today.

Any other ideas?

[79coyotefrg]

Did you have the engine balanced?

thats not going to cause it to run rough at that rpm,  it would make it rattle the entire truck,
 BUT if its a new Toyota block,  it IS balanced

[unclejpl4x4]

subscribing

[79coyotefrg]

The engine was a new short block from Toyota - so I think it was balanced. I have checked all of the grounds and even added one, I will check the EGR valve today.

Any other ideas?

did you set the base timing correctly??  sounds like NOT

http://board.marlincrawler.com/index.php?topic=42589.0

[brainlessfool]

thats not going to cause it to run rough at that rpm, 

ture, butt we never know how much epx. ppl have on here asking ?s. I took a 6.2 out of my truck and put a 350 in.

at 55 in 2snd getting on the freeway man! it would nock your teath loose. and so I dumped the 6.2 torq. converter for the 400 and wow. butt point is we're not there and seat digs. are hard to do. how one person says it feels is always diff. than how you or I would dicribe it. 

[*ROKTOY*]

thats not going to cause it to run rough at that rpm,  it would make it rattle the entire truck,
 BUT if its a new Toyota block,  it IS balanced

The dude didn't say that till after, he said in his main post he rebuilt it.

[79coyotefrg]

ture, butt we never know how much epx. ppl have on here asking ?s. I took a 6.2 out of my truck and put a 350 in.

at 55 in 2snd getting on the freeway man! it would nock your teath loose. and so I dumped the 6.2 torq. converter for the 400 and wow. butt point is we're not there and seat digs. are hard to do. how one person says it feels is always diff. than how you or I would dicribe it. 

very true

[dms1 [OP]]

I am pretty sure the timing is set correct - when jumpered it is at 5* and unjumpered it is at 12*, when I give it throttle I can see the timing mark jump to the left about two inches from 12*

It runs great at idle and up to 3000 after 4000 it sounds like it is running fine also, so just between 3000 to 4000 it stumbles

[dms1 [OP]]

Here are some pics of my timing setup:

[dms1 [OP]]

So, I replaced the TPS with a new one and re checked the timing and the engine still runs real rough between 3200 and 4200 RPM. I pulled the vacuum hose from the egr valve and plugged it and the engine seemed to run worse. I am going to re adjust the valves tomorrow but I don't think it will make a difference since I re adjusted them after breaking in the engine - oh and the entire valve train is new.

Can anyone recommend a good mechanic near LAX or Torrance, I am tired of messing with this engine - runs great up to 3200 RPM.

[dms1 [OP]]

Well, I spent last night reading the manual and noticed the EGR valve has two air hoses to it, one on top and one on the neck (tube), when I did my testing I only removed the one on the neck, when I remove the hose on the top it runs 90% better with only an occasional miss, so I am going to replace the EGR valve, the weird thing is I cleaned it out real good and tested it it when I had the motor apart, and it seemed good, I am going to order one from the dealer unless someone can recommend a better aftermarket EGR.

Also, would it hurt driving the truck with the top EGR hose disconnected?

Thanks to the guys that offered advise

[drayday55]

good find! im gonna swap a newly rebuilt motor very soon!
i think im gonna leave some of that stuff alone.   the more you mess with it the worse it gets.
i like to over do everything so i need some restraint.

how do you like the rock products from enginebuilder?
i have his timming kit and the truck knocks on startup and this is with 3000 miles on the t chain
im building a replacement motor, think im gonna use lc enginering and stock parts to rebuild.