Won't rev past 4300 when floored

[SV_Dude]

I just did an SR5 cluster upgrade and now that I have a tach I'm noticing the motor won't rev past 4300 RPM when floored. If I use a small amount of skinny pedal the motor will rev all the way up to 5700 RPM or so then hit the rev limiter. But, when I use half or full throttle the motor will flutter around 4300 RPM.

I may have some questionable vacuum lines but I am not sure if this could be a culprit because this problem is dependent on how much gas I use.

First thing that comes to mind was the TPS. So I pulled the throttle body and checked the TPS. It was out of adjustment so I moved it around till I got these results:

VTA-E2 (0.0mm) .70k Ohms
IDL-E2 (.57mm) .11k Ohms
IDL-E2 (.85mm) Infinity
VTA-E2 (OPEN) 4.55K Ohms
VCC-E2 (ANY) 5.83K Ohms

All parameters are good so I know the TPS is good. I also checked the AFM and came up with this:

E2-VS 450 Ohms
E2-VC 180 Ohms
E2-VB 280 Ohms
E2-THA 1.87k Ohms

I know the E2-VS is out of range by 50 ohms (should be 20-400) and according to the FSM, the AFM should be replaced. But with the AFM only being off by just that little amount, I am sceptical if this would by my problem.

btw: this motor is a 88 22re (4runner) with a fresh rebuild about 2500 miles ago. The motor has a 268 cam, Street RV head, LCE Header and is bored .030 over.

And I am getting a code for the water temp sensor and o2 sensor. I doubt these are related to my problem because as stated before, the motor will rev all the way if I use a light amount of gas.

So... Here's where you chime in

 

[GonOvr]

Well your on the right track.

Pull the plugs and see how they are burning.

How does it react under load? Does it sputter to 4300?

One thing, what did the cluster come from? Further more what is the cluster's red line?

 

[SV_Dude]

Redline is determined by the ECU. But, fwiw, the redline is marked at 5800 rpm on the cluster. I think the cluster was out of an 87 4runner.

The plugs are good, cables, cap, rotor, fuel filter, air filter, ect are all brand new.

Could this be a knock sensor thing even though I'm not getting a code? I'm actually leaning towards it being an AFM issue though.

 

[GonOvr]

Id say swap the AFM for a known good one. At least to check it and rule it out.

Also for giggles check the timing. I know it's a fresh rebuild, but stranger things have happen.

 

[SV_Dude]

The timing is spot on with no fluxuation at 5*.

I'm on the hunt for an AFM as we speak.