Well I went again on Wednesday night and the conditions were supposed ot be good...but as the Wednesday came closer and closer the forecast changed alot. It them was in the 80s and humidity was 86%...it was supposed to be 65 degrees and 75% humidity, but that didint play out. Regardless, the weather didnt stop the big ole box from running faster than it has before! I went with another member from here...Intel486, and 2 friends of mine with 4cyl Tacomas came along also. Everyone had a personal best. Intel ran a 16.557@81.75 in his 00 4.6L F-150 and on our first run we both pulled the exact same .261 R/T which we though was real impressive. One of my friends in his 2.4L tacoma ran a 15.230@91.26mph (NX 75 shot ) and the other ran a 16.233@81.45 just barely beating me lol. But I was happy none the less, I ran:
60 - 2.229 (I was upset I spun off the line and it cost me a 2.1 60!!)
330 - 6.669
1/8 - 10.366
MPH - 66.76
1000 - 13.602
1/4 - 16.379
MPH - 80.90
I also found out where the dead spot in my power is for sure...its once I shift into 3rd..if I listen to the engine I can hear it kinda "sing off tune" a couple of times where the power feels like it comes and goes...but then it starts to pick up and start pulling again. Its not an ignition problem and I'm debating it being a fuel problem. It only happens between roughly 3300-3900rpms, and only in 3rd gear, if I get over 4k...I ran run it all the way up the redline with no hint of the symptom. I think that it may be a fuel demand problem, I know I am not maxing out the stock system, but I believe that when I go into third and the TQ locks up and the ratio is 1:1 that load increases (3rd and 4th put alot more load on your engine at the same rpms) that intially the fuel system cant flow wnough fuel fast enough to feed my engine and it takes it a second till it catches up before the power comes on hard again. I may go onto a dyno again in the next couple of weeks...just to see what the power is like over my old pulls and to see if I can find this problem on the dyno. Other than that the 5500# truck is pulling its *** off and I think this is the only thing holding me back from a real low 16 or high 15 second pass. So tell me what yall think.

 

Not positive, but I don't think the TQ will lock up at WOT. Its good you are so "in tune" with your truck's performance. Very descriptive as to whats going on here.

I wonder if your fuel pressure regulator has a soft spot. What makes you think its not an ignition problem?

What about an actual slip in 3rd gear? Or the TQ attempting to lock up, bogging it down temporarily. Can you duplicate it often?

 

There is a way to eliminate the TQ electrically. Look into doing that and then see if you can duplicate your dead spot

But the more I read your post the more I'm thinking its an actual slip in 3rd.

I don't know much about your trans tho sorry. All autos generally function the same.

 

NO its nothing with the tranny....Once I go into thirs...i dont know how long it is till the TQ locks up...but I can feel it do it and I can watch the rpms drop a little like they should....the the power fallout I feel is something completely different...the rpms climb, but I can just feel the power coming and going a couple times till it starts to go fine again. Now this problem isnt like a huge power fall off and it really cant be felt...but if you listen to the tune of the engine it is evident. What I'm saying is its not like the power is going away completely and then hitting hard again...its just like it feels like its loosing some for a second, like maybe some timing is pulled out for a second then goes back. It is hard to explain, and you have to really be listening for it...but its there. I dont think its ignition related because I have no problems in any other gear or above 4k in 3rd...it doesnt feel anything like a miss.

 

Beastie,
Just a shot in the dark, but ask Mike Troyer if you have tip-in-retard in your computer. I know on manual transmission Mustangs, the computer takes timing out of the motor when you shift. I am just wondering if your truck does the same thing.

 

I talked to Mike today...he was kinda stumped also...he threw out a few ideas. But it isnt right after the shift...its maybe a second or 2 later