One of the sales guys has been pleading with me to take him for a ride in the L, so I took him out today. Felt something that I wasn't to happy about, but don't know if it's a problem. We were on the highway, cruise control set at 65 MPH and AC on. Outside temp was 76 deg. When I stabbed the throttle the L took off like a rapped ape as it's prone to do, but noticed when I got to like 100 MPH I would get periods where the power seemed to fall off a little and would then suddenly jump back. Can't really say it was a hisitation because it didn't spit or sputter and didn't hear any detonation, just kind of felt like something was holding it back and then letting go. It did this like two or three times. The guy riding with me said he didn't even notice, it just seem to pull like crazy. I shut down at 120 and it was still pulling.

Has anyone else experienced this? Could the AC have had something to do with it? And lastly, is this something I should be worried about? When I had it on the dyno they ran the truck in second gear and the detail printout didn't show anything wierd. The A/F's were like 12.1 at 1500 RPM and steadily dropped to a low of 11.1 at 5500 RPM when the rev limiter kicked in.

 

The only problem I see is that you broke the law and put you, your passenger, other motorists, and anyone in the vecinity in danger.

 

that and you dyno'd in second gear.

 

When you say “stabbed the peddle” does that mean you did NOT do WOT? If so then it very well could have been the AC compressor. When you are at WOT the AC compressor is cut off.

 

yeppers ... gotta do 3rd.

 

You don't have to dyno in 3rd gear. Mustang dynos let you do a simulated 1/4 mile run from first gear...

 

It's totally normal
OR SOMETHING ???

No really Mart Man, I use to complain about that all the time
when I started first doing Hi MPH Blast's, I don't remember if it was the Hi Flow Filter, or the Accu-Fab that FINALLY got rid of it forever, but one of them did.

BTW, MAKE SURE YOUR FUEL FILTER IS NOT CLOGGED

Relax, it's nothing.........................

 

My 2000 Lightning does the same thing your describing. Mine does it around 95mph. Ive noticed it everytime I went to the track, always in the 90mph range. Ive wanted to resolve this for the longest. If you find out anything please post. Kinda seems liking the torque converter is unlocking for a split second.

 

Let me start by saying that I am sorry for getting off topic here and I do not want to start anything with anyone.....just wanna say something. Mart Man, I'd try to do what Rob was saying. Just replace the TB at first to see if that helps. It's a quick change and shouldn't be hard. But as far as "putting you, your passenger, other motorists, and anyone in the vacinity in danger", while may be true, I don't feel that answered your question. We all do that very same thing every time we get on the gas no matter how fast we go. So I guess whoever said that doesn't ever break any laws on the road and is the perfect citizen. I'll tell you whose dangerous and puts all other motorists in danger. It's soccer moms driving 6,000 pound suv's not paying attention to anything around them while driving 50 mph in the left lane of a four lane highway who can swerve right into you the second she realizes she is about to miss her exit. It's the jack@ss who cuts out in front of you 1 second before you slam into the side of him just to beat you to the red light. It's also the person who slams on the brake within one millisecond to turn and then realizes "oh, it's not this turn, it's the next one". It's idiots like that who cause danger to all of us and while doing that speed isn't the safest thing to do, we have all done it and will continue to. I just would like to think that you choose to do it at the right time/place. I appologize for going off topic on this post.

 

I know what your saying Mart Man and my 2002 does the same thing. When I punch it from a dead stop, it pulls hard through all the gears no problem.

If I get on it anwhere from 30-55mph (second gear) it pulls hard but I can feel a slight surge while it is accelerating. I feel this surging about once every 3 seconds until it shifts into 3rd. It seems to just do it in second gear.

 

I appriciate your response. I was on a divided HWY (two lanes in each direction seperated by at least 60 ft. of dirt between sides of the HWY) There was no traffic on my side at all, and no intersections for better than one mile. The road is perfectly flat and straight. Plenty of room for going fast and slowing down without having to jump on the brakes hard and warping the rotors. This was also the first time I've had the L over 100 MPH. I did have the L at WOT, I already have a Accufab TB and high flow air filter, had my fuel filter changed a 3000 miles when I changed the oil. L only has 4000 miles on it now. One thing I may check is the outer wear filter. One of my co-workers said that when I had the hood up and reved the motor, they saw the outer wear filter suck down on the filter. Not really sure, but it's not a huge problem since I don't do long WOT blasts very often. Actually this was the first one in the 10 months I've owned the L.

 

Hay guys, I was searching out some information on my surging and came across this post. I just wanted to share with you some information that I found on my truck. I was having the exact same symptoms that Mart Man 03 L describes. In fact he described it better then I could.
I just recently put a centrifugal type supercharger on my truck and am hitting 8lbs of boost at 5400 RPM. I am having a lot of trouble with the belt slipping. If I remove the belt, I can pull to 5400 RPM without a bit of hesitation (although much slower) so I was pretty sure this is being caused by belt slip. I have a Powerdyne and I fear tightening the belt too much since these things tend to burn up bearings. If I over tighten the belt then the surging goes away.
I suggest you guys with these symptoms switch to a Gatorback belt. I am waiting for my Gatorback to be delivered since mine is a non-stock length. If you are already using one then perhaps you should check your tensioner and replace if needed. I am willing to bet belt slip is causing your symptoms.
Good luck.