I am experiencing a surge when trying to go a steady speed.
First I will tell you what I have so it will be easier to help.
2000 frc m6
A&A procharger kit with 3.85 pulley
LG big 3 catback
Everything else is stock.
Car ran really good on Andy's base tune.
I took it to get a tune done on the dyno and made 479 hp and 429 tq at the rear wheels. It was making 11 pounds of boost!!!
The car drove perfectly after the tune for about two days so I don't think the tune has anything to do with the surging. The vacume guage moves in sync with the surging and throttle input will either cure or mask it not sure which. The car seems to make really good power, enough so that I am going to be putting my new clutch in sooner than later as the stocker will now slipp when getting to aggressive. It did not last a week! I just want to get the bugs worked out of the system before tackling the clutch.
I was thinking that it may be my blow off valve.
I have no codes other than the ones triggered by the traction control and dyno session. Vacume looks really good at idle too. Normally 15 inches.
Fuel pressure is normally 62 lbs. It changes with tempurature though.
Any help or input would be appreciated.

 

Did you get a street tune with it. Sounds like your AFR is off cruising. That will cause a surge. That was my issue. Bought HPtuners (wanted to do it myself) and done a street tune. No more surge. Just a dyno tune won't do it. Needs to be on the street and dialed in there too.

 

I would start by checking all the hoses and clamps and make sure everything is tight. Since it is a new install something could have worked loose and be sucking in air.

Your BOV should be open under vacuum.

 

Yes a street tune was done first. Then the dyno tune after. Can I check this in real time while driving if I get a air fuel ratio meter or do I need a data logger? Should I just take it back to my tuner? Dont really want to pay another $500 and a hour and a half drive one way to find out that it was something else. When you were experiencing this problem did it occur when the cruise was on also? I would love to do the tuning myself, but I really don't think I am capable. Although there is a Greg Banish cd rom for sale in the parts section.

 

I will double check every thing today. But what I was thinking was that maybe the blow off valve was not staying open under vacum and making a little boost and then opening and letting off creating a cycle of surging. I have good vacum on the guage so I kind of over looked a leak as a possible culprit. But it doesn't hurt to look. Maybe all that boost has pushed something open that is not supposed to be.

 

I just put vacum to my bloww off valve and it does not hold vacum. It pulls air right through. I am guessing that, that is not right.

 

I talked with Steve at A&A and he had me check the blow off valve by unhooking the vacum source and driving it with out getting into boost and the valve seems to check out. The surging still persists and it will do it with the cruise on which I had not had noticed earlier because I only use it at highway speeds (75 to 80 ) in 6th gear. I have contacted my shop and they are going to get back to me later today. I hope they can resolve my issue. I am thinking now that since the car only acts this way after it has warmed up that it may be afr.

 

Sometimes a surging//miss can be caused by a bad O2 sensor.

 

Yep same issue as me. It was fine when it was cold, but once it warmed up it started surging. And my issue was AFR. It was running too rich. 12.5 AFR at cruise to be exact. Now that it is dialed in, no more surge. Drives like stock. The surge was very annoying.

 

This is something else to look at. Mine were new, so I took that out of the equation.

 

I had some weird things happen when a MAF sensor went out.. it was on a camaro though. would run fine when cold but go all to crap after it warmed up.

 

That is why a lot of people like speed density. I am not at the power levels yet that would require that. Although it sounds easy and inexpensive. A 2 or 3 bar map sensor and some tuning.