What do you guys think of this, 2002 SS, A4, pacesetter longtube headers, hooker cat-back, 3400 stall and mickey dot's, I have a surging problem on the bottle. The previous owner said he thought it surged on the motor also, but I've never felt it. Spraying a NX 150 shot, it has tr6 plugs, a 255 pump, fpss, and window switch set at 3000/5600. I've ruled the fpss switch out because I've disconnected it and had the same result. I've replaced the fp dampening device (looks like a regulator on the rail, above the intake), and that seemed to get rid of the problem, but it wasn't shifting till 6100 spraying, so I put the 6000 pill in the window switch and ran it tonight, 1st-3rd. It ran great from a 15mph roll, the nitrous shut off just before the shift into 2nd (which is what I wanted), and started pulling towards 3rd, but when it got to about 5300-5500 it felt like a slight surge twice, then it shifted into third perfectly and pulled hard till about 4500 and I shut it down. I'm running out of ideas and money, don't want to just throw parts at it, especially if someone has had this problem themselves and know what fixes it. I've noticed even at idle the gauge on the rail seems to fluctuate a bit. The closest dyno is 3.5 hours away. Let me know what you guys think!!!

 

Has the fuel filter been changed? Do you have a "hot wire" kit for your 255 pump?

Matt

 

I agree with Matt on checking the fuel filter. It is one of those parts that most people seem to over look when it comes to checking/changing parts on a regular basis. Also, does it only surge in 3rd? Or does it do it in other gears as well? It could be the tranny.

 

The car only has 15k miles on it, and the filter has been changed twice. What is a hot wire kit for the pump? I'm not sure if I have one of those, the original owner put the pump in with the nitrous kit. This problem may be why I got the car as cheap as I did. As far as gears go, I've only ran it last night and the only gear that it "surged" in is 2nd, just before the 2-3 shift. The tranny has an aftermarket servo and thicker band, and he changed some solenoids but that is all that I know of.

 

The car only has 15k miles on it, and the filter has been changed twice. What is a hot wire kit for the pump? I'm not sure if I have one of those, the original owner put the pump in with the nitrous kit. This problem may be why I got the car as cheap as I did. As far as gears go, I've only ran it last night and the only gear that it "surged" in is 2nd, just before the 2-3 shift. The tranny has an aftermarket servo and thicker band, and he changed some solenoids but that is all that I know of.

 

I would try it again and if it only does it in 2nd again I would start looking at the tranny. It could be a smoked clutch pack.

 

A "hot wire" kit is a new wiring harness that is run from the alternator or battery back to the fuel pump to provide more voltage. With out it the pump will pretty much work as a stock fuel pump. Most of the time the hot wire harness is ran along the fuel lines, so you could check there and see if anything is there. Or just check the alternator and battery and see if it's there.

Like Jeremy said if it's only happening in one gear more then likely it's a trans issue.

Matt

 

At what mileage do you n2o guys like to change out your fuel filter?

 

I haven't checked for the "hot wire" kit yet...is that a factory or an aftermarket item? If aftermarket, where can you get one? Well, tonight me and about five other f-bodies cruised down to Liberal, KS to "have some fun" and I noticed that it does have a slight hesitation around the same rpms spraying or on the motor, I even slightly noticed it in 1st but 2nd or 3rd is more noticeable. I'm starting to wonder if I might be getting some knock retard and need to back the timing down a bit more. I have ls1 edit for it and we have done some adjusting on the tranny and backed the timing down a couple degrees for the nitrous but maybe it isn't enough. I will put a scan tool on it in the morning and see what I can come up with and go from there. That might give us a little more info to diagnose this problem. I almost forgot, I don't have any filters on the nitrous kit whatsoever. Any other ideas would be appreciated.

 

It's an aftermarket item and we carry them. Scan her if you can, I don't think it's timing/knock issue, but then at least you can rule that out of the equation. You might want to pull your TR6s out and just double check the gap too and then replace them.

Matt

 

Since you do not have heads or cam you do not need a hot wire kit.Save your money.The intake walboro will support the 150 shot. Give me a call when you get a chance. Ill walk you through a few things and we will figure it out.
Dave

 

To rich on the fuel jets or not enough bottle preasure .

If it was starving the fuel , it wouldnt surge , instead it would pull like a raped ape and burn spark plugs straps .

The tranny wont surge , it will just slip like a bitch but thats a different feeling all together

You can save a lot of time and hassle by putting a wideband in the car .

You will be able to adjust the jets and a/f to 11.5-11.7 anytime .

Its around 250 bucks but you will always know whats going on at any given point in time with your a/f + you wont have to make the 3 hour drive to the dyno just to find out where your a/f is at .

Cold/hot weather will change your a/f over night ,, what was good yesterday isnt always good today .

 

Where can I get a wideband for $250? My buddy "Wicked 1" spent around $500 for his I believe.

 

LC-1 is 'bout that price

 

I had the same problem. Mine would surge really bad! What we found out on the dyno at G-Force was I was hitting my window switch and the spray would pull out alittle. How we found this out was-pull you top pill out on the dyno and spray it all the way threw, never surged. My converter would flash up high and hit my top pill. This would pull the spray out and cause a surging sensation. We adjust my pills and shift points with Rev limiter on the dyno and it fixed everything. I even went to the point of adding a in-tank pump and adding 42lb injectors thinking it was a fuel issue. NOT-I had the T-rex in-line and 30lb inj already. My converter just flashed hard with the spray! Small price to pay to spray. Good Luck, hope this helps!

 

If it was the converter flashiing to a higher rpm and touching the 6,000 pill on the window switch too soon, couldn't you pick that up on a tech2 by watching the rpm? Or is it too fast for the scan tool to catch it? Because I've made a couple of pulls with the Tech2 taking a snapshot and the RPM never flares. What do you think?

 

We couldn`t see it by the rpm`s at all. It was really funny! Mike and guys where really suprised when we figured it out. It didn`t do it when my stall was 3200rpm. Just when I restalled to 3800 did it get me.

 

Thanks "beardws6" I'll give that a try and see what I can come up with.

 

I'd still pull the plugs like someone else stated earlier. I better to check things out first before going out and buying stuff you don't need. It may be time consuming but alot cheeper if thats the problem. Hell if you decide to take them out you mise well replace them while your there.

 

True about the plugs. Better safe than sorry!