Loss of power, Car barely driving over 3k

I have an rb20 in my 240. One problem that has been bothering me for awhile. Sometime when I hit boost (sometimes even before) the car will just lose all power. I could floor the car and it wouldnt move one bit. It usually continues to stay like this until I switch gears (sometimes will continue) or let off the gas and wait 2-10 seconds.

Been told that this is a vacuum leak. Wondering if it could be anything else before I start changing all my hoses lol.

Also been told it could be a faulty FPR? not really sure though

Thanks in advance!!

Last night it started to get really bad. Was on the highway and it felt like I just hit a wall? or something. Ugh not sure were to start looking

do if feel like turbo lag, or more like when u hit the speed limiter or rev limiter. do you have anything t’d off ur fpr vacuum, if so hook the vacuum without any t’s to your fpr.

Maf

same thing happened to mine, cause i had a boost gauge teed off my fpr. check that it might not be getting enough vacuum. also sometimes the maf needs to be cleaned or wires are messed up, but u usually cant go over 3k when that happens

Check the throttle position sensor and maf.

If you think its a vacuum leak, turn it on and pop the hood. Listen for some air rushing sounds. If you think you hear something but dont know where it is, spray ether or parts cleaner around your vacuum tubing and the idle will increase slightly.

Well, this is odd. I didn’t think it was anything to do with the fuel. But I put in fuel injector cleaner today and it runs amazing. Not sure if its because of that? or if its just tempermental lol.

I cleaned the AACV today seemed to help a little bit.

I still think I have problems though, im going to retrace the Maf wiring, and try my friends maf. Hopefully it runs better then.

Thanks for the help!

could have a sticky injector. theres a trick for listening to an injector to see if its working. go get yourself a long screwdriver (preferable flat head) and put the tip on the injector (apply light, but firm pressure) and then put your ear against the handle of the screwdriver. you should be able to hear it tick as it opens and closes.

if you find that one is dead, check the wiring first for corrosion, breaks, so on. and if thats fine, ohm out the injector (this I’m not that smart with which is amazing considering my electronics background, lol. Ask around about how much impedance and injector should have, resistance, so on. I want to say most of them have that information printed on them… who knows)

do you have the stock ecu?

did you run low on gas lately? I always say this but change your fuel filter. I had that same problem, idled fine but was hit or miss above 3500 put in a new filter and it was good again. Plus this is cheap and easy to do

to add on to Steve on this one, it may be possible that the pump lost its prime.

personally I’ve never had this happen before so I dont know what it would act like, but I’ve heard of it happening.

K well it still does it. Ugh lol. The fuel filter is basically brand new. Its from a z32, installed last yr around Nov and I didnt drive it until May this year.

The fuel pump is new too. I could have possibly screwed up the wiring… maybe its loose or something.

Ill try the injector thing. If 1 injector was broken it wouldn’t cause the car to have 0 power at all, wouldn’t it just be sluggish?

And yes I have a stock ECU not tuned or anything. The Rb20 is completely stock.

It could be a knock sensor as well. When it goes it will detect knock even though there is none and will retard your timing, resulting in loss of power/hesitation. Get it checked out.

But my car doesnt do it all the time. Only certain times. Usually after driving it hard (bouncing off rev limiter). But when I drive around 2-3k rpm it doesnt happen (out of boost) its weird…

Exactly, a faulty knock sensor will do that at random.

How do I check this?

you can bypass it by putting a resistor on the wire for the knock sensor coming from the ecu. Cheapest way to check, but should only be temporary. You can also check its voltage, look up in the fsm for the requirements.

Dont think its my knock sensor. I replaced the wiring going to my maf. seems to run alot better. I think it was corroded before. I could run my hand along the wire and the car would stall out.

Also I pick up a wideband, think im running extremely rich also.

Thanks guys!