Need some help with troubleshooting ideas

[harleyreb1]

My car is stumbling at around 4.5 to 5k rpms. It dosent seem like a spark thing more like a fuel issue, but everything is brand new! 155lph fuel pump , brand new 24 lb injectors, all on new rebuilt engine. The cars runs like a top except for the stumble. Anyone think it could be valve float??? Also I have an adjustable fuel pressure regulator set to 41 and then I put it at 43 lbs, still the same stumble. I've checked the plug wires and no arching or burnt holes? TPS is set correctly and timing is at 10 BTC.

Mods:
Comp Cam XE 264 HR
Stock MAF
Stock TB
Shorty Headers
GT 40X heads
Comp ratio around 10.1

 

[KC/COBRA]

Clean your maf sensor, a guy just posted the same problem on here a couple of weeks ago and that took care of it. Hope that works for ya.

http://www.svtperformance.com/forums/showthread.php?t=518972

 

[harleyreb1]

Any good way to clean it?

I've sprayed MAF cleaner on it and let it air dry, I have heard for using a qtip? Any better ideas??

 

[tunedin302]

How about your oxygen sensors? New?

 

[harleyreb1]

They are new bosch units

Almost everything is new: sensors, distributor, plugs, plug wires...etc

 

[93Cobra#2771]

Most importantly, do you have a check engine light? Have you pulled codes?

 

[04MystiCobra]

Feel your upper intake. Is it unusually hot? Do you have the correct size pushrods? Did they spin in your fingers after the rockers were bolted down?

 

[harleyreb1]

Answers

No check engine light, I haven't pulled any codes, I'm 99% certain the rockers are adjusted correctly and the pushrod length is correct. Also upper intake is cooler than lower by about 30+ degrees( I have a 3/8 inch spacer)

 

[harleyreb1]

I fixed it

Ended up being the TFI module( on a brand new aftermarke distributer)
Bounces of the rev limiter now!!!