I used to have the boost up at 1.35bar with safc and mbc. Someone told me I just turn the boost down until I have the fuel pump and bigger injector. So, I turned the boost down to around 1.24bar since a month ago. I installed the fuel pump last weekend. No injector yet. This afternoon, I raise the boost up a little, just half a turn, to about 1.28bar.
I rev the car up to redline on the street. At 1st gear, at around 5k rpm, the car hesistate a little, then "baa.....ba.....baaa....."sound like misfiring pass 5k rpm. Shift to 2nd, at around 5k rpm again, hesistate a little, then sound like misfiring again. I stop the car, turn the boost up to 1.22bar. No problem. Try turn the boost up again, same thing happened, i.e. hesistate, then sound like misfiring. HELP!! What's wrong with the car??? I am going to the track tomorrow. Somebody please give me some light as to what is happening with my car..... HELP PLEASE!!!!!!!

 

Have you had your car flashed before?

 

You must have an un-tuned aftermarket intake huh?
.

 

check your spark plugs.could be breaking down under load. although if you are runing less boost and it is ok till redline it may be something else.What type of FP did you install? Try swapping back to the old pump and check it again.possible faulty pump.

 

Check your connections on the fuel pump

 

Thanks for the quick response.

No flash. Car was tuned about 10 months ago with SAFC. Fuel pump was walboro 255.

Checking my spark plugs now.

Do you think the fuel pump has something to do with this? Why would it?

Thanks.

 

Btw, I have hks rs intake, hks cat back and downpipe. Stock engine, turbo, bov & cat.

 

Install a fresh set of NGK BPR7ES gapped to .026 and see how it goes.

DO not listen to whoever told you that was too much boost for no fuel pump and no injectors - that person was dead wrong. 1.35psi is STOCK BOOST! Also, you need to get retuned after adding the fuel pump if you want to be optimized. You should sell the SAFC and get a basic $199 mail-in flash. You'll be much happier.

 

yep. Warrtalon is absolutely right except the part about getting rid off the SAFC. i said the same thing on Socalevo.net in his thread. are you sure it was misfire and not bogging?? maybe you are running rich. turn up to 1.4-1.45 adn see what happend?? alos makesure your setting are correct. makesure you selected KARMAN and also is everything at 0 ??

 

I doubt he's bogging - a misfire and sputter is pretty easy to notice. He will make much more power with a flash than the SAFC, and it doesn't sound like he knows how to tune it himself, so it's not that useful.

 

No. I don't know how to tune the safc. I will keep the safc at this time.

I changed the spark plugs to the stock ones. Reset the computer. Took a spirited drive. The problem seems to go away now. I think the problem was I didn't reset the computer after installing the fuel pump. Dumb me.

 

Resetting your ECU will have no effect on the problem you were describing. It was either you spark plugs or the sparg plug wires. You don't need to get retuned for the Walbro, although a good flash will probably make more power than your SAFC and it should have better driveability.

l8r)

 

i think ur hitting fuel cut.

 

you got me there about the "tuning himself part"

 

good thing at least you got your car running good for now