surging problem again

[quiksilvia]

about a month ago i posted with a power surging problem, the boost gets to 7 psi and its boosting, but the power is on off on off, and it surges. i have replaced the head because of a stripped spark plug hole and i thought that would take care of it. but its back again. any suggestions>? thanks

[Movingviolation240]

have you checked the MAF wiring, or for leaks in your intake. Sounds like it might be somthing allong those lines.

[Wuss]

maybe its your bov or diverter valve, whichever you have. Make sure it's not sticking and/or leaking.

[quiksilvia]

but when i let off the thottle, the bov is in full effect, the boost is there, its not getting to the motor, ill check all hoses etc.. but i was wondering if u guys experienced this before

[Wuss]

the bov can still be audibly heard even if it's leaking or sticking.

I had this problem on my 1.8t where the valve on my HKS SS was sticking and causing my motor to surge. I oiled it up and it fixed the problem.

[quiksilvia]

so i need so lube....

[quiksilvia]

i listened to it while driving and it sounds like a lot of air is coming through the bov, as u described. what did u use to oil it?

[Wuss]

I just used some WD40.

I'm not nessecarily saying it's your BOV, just in my case that was the problem.

exactly what kind of surging is it?

When it was my BOV, I would step on the gas, and my car would accelerate fine, but then it would start lunging forward in little spurts like it was getting a kick in the arse every 5 seconds.

[quiksilvia]

thats what it felt like, and i could hear air going out of the bov while on the throttle, i lubed it, now its time for a test drive

[Gladius]

WD-40 is not a lube. It is a solvent. So be careful what you apply it to. It will actually strip away any existing oils and lubes. Therefore compounding the problem later on. It is good for loosening rusty parts and getting lawn mowers to start.

[quiksilvia]

that wasnt the problem anyway. the bov is ok- i think. i also noticed that the throttle response is really delayed. so do these add up to anything?

[Tai Mai Shu]

Yes it adds up to a faluty MAF sending wire to your ECU like mine, run a temp wire, from the MAF (signal) to ECU (signal) And see if it clears your problem im 90% sure this will cure it. In the end I got some Audio Singal wire and just ran the single cable from the MAF to the ECU since it is thicker wirer that is sheilded I know it works well, and I shouldnt have that problem again.

[quiksilvia]

i hope ur right, thanks, ill give it a try. did u have the 2 same problems?

[sgpnismo]

I am having the excate same problem right now also my sr is accelerating fine but when trying to keep speed it feels like im letting off the gas every couple of seconds then giving it gas again.

[Atl_SIL40]

i think i am having a simmilar problem. Im trying to run about 14 psi or .9 or so kpa and the boost gets up to .9 quick but then falls about 3 psi and then it jumps really fast back and forth from about 11-14 psi. It just started happening after i got my FMIC and i also got a blow through MAF set up. What could my problem be.

[llamabeta]

Just installed my SR20DET, started right up though. Runs very well with the exception of the surging I'm trying to figure out.

I have the stock SMIC and BOV. Everything is tightened down pretty well. Thinking either MAF (Itself or bad wiring), BOV.

I was also thinking there could be a possibility of the CAS being off, so I am going to set that again.

[RMiller]

I'll bet it's something simpler. You might have a boost leak. This would explain the surging and the stumbling. MAF problem would not explain surging. If you have a leak, the wastegate will not open when it should because the pressure signal will not be a true 7psi or whatever. Also, if there is a boost leak the MAF will measure air sucked in by the turbo and the computer will deliver lots of fuel, but if air is leaking out before it gets to the engine, you will run rich, causing stumbling.

I have had intercooler pipe couplers pop off tons of times, and if I'm not careful, my turbo will spool beyond its efficiency range, and cause surging. It's also almost impossible to drive, it runs so rich. Your stumbing problem isn't as bad and that may be because you have a smaller boost leak.

What is your idle at? If it is higher, or if you had to adjust it quite a bit to lower it to where it should be, the leak will be after the throttle body. If you always had normal idle, it may be before the throttle body.

[llamabeta]

I'll bet it's something simpler. You might have a boost leak. This would explain the surging and the stumbling. MAF problem would not explain surging. If you have a leak, the wastegate will not open when it should because the pressure signal will not be a true 7psi or whatever. Also, if there is a boost leak the MAF will measure air sucked in by the turbo and the computer will deliver lots of fuel, but if air is leaking out before it gets to the engine, you will run rich, causing stumbling.

I have had intercooler pipe couplers pop off tons of times, and if I'm not careful, my turbo will spool beyond its efficiency range, and cause surging. It's also almost impossible to drive, it runs so rich. Your stumbing problem isn't as bad and that may be because you have a smaller boost leak.

What is your idle at? If it is higher, or if you had to adjust it quite a bit to lower it to where it should be, the leak will be after the throttle body. If you always had normal idle, it may be before the throttle body.

Yeah, Ill be sure to double check all my connections this weekend. I never had to adjust idle. It idles normal. Dead on

Thanks for the info.

[RMiller]

No problem. Post here when you get it resolved.