problem when boosting
 

Ok I set my car to high boost and it accelerates great...then I hit 1 BAR and BAM! Its like I hit a wall. If I let off the gas a little so the boost goes down its fine. Any ideas? I have the stock turbo upgraded to a T04B comp. side and a larger turbine wheel in the stock housing. Now I am running a walbro, 4x720cc injectors and an s-afc tuned all the way rich to be safe for now. My car wouldn't run right without it tuned up to at least +25 in the 4k plus RPM range. Am I running extremely lean somehow? I was thinking I possibly have a boost leak that only shows its face under a certain amount of pressure. I know the only way to be sure what the problem is is to hit the dyno :( Guess I will try that soon. Just wanted to see if anyone had any similar problems. Thanks.

buy yourself a afr meter ...you gona save a lot on dyno time :bigthumb:
you could be to rich :www.innovatemotorsports.com/resources/rich.php

Stock ECU?
FCD?
Overboost fuel-cut?

The S-AFC should be turned down from +25, so something is really wrong...


-Ted

Do you guys think I am not getting good enough voltage to my pump? I never have done a rewire. Can someone postme a good link to a rewire write-up? Thanks alot.

Stock ECU
FCD installed

I dont think it's a fuel pump issue because if it was you'd already be in trouble. I think something is really wrong if you have to turn up your 720s +25% above 4k. Were you thinking your fuel pump is not getting enough voltage and you had to up the percentage on the injectors to make up for it? I'm not sure if that's plausible because the pump would still have to keep up with the injectors and at a certain point one of them will be pushed too far.

With those injectors you should be turning them down, not up. If the engine won't run right unless you crank the settings ridiculously high then you obviously have a serious problem somewhere and shouldn't be boosting to 1bar!. Even with a basic understanding of EFI you should realise that increasing the ECU's calculated fuel requirement by over 60% (720/550 x 1.25 = 1.64) should never be necessary.

Have you upgraded the pump? Have you checked the fuel rail pressure?

I have realized that there is a problem. I do have a fuel pressure regulator but no clue what the pressure is at right now. I know I need to get a fuel pressure gauge to be able to properly diagnose the problem. I haven't been boosting it any more since I noticed this when I turned the boost up. I am going to get a greddy fuel pressure gauge as soon as I can after the holidays. But I also am going to rewire the pump to be sure its getting good enough voltage. I do have a walbro 255lph pump, mallory adjustable fpr, 4x 720cc injectors, fcd, and s-afc. I should be pretty good for 300rwhp+ I would think. Just need to get it setup right and tuned.

i think you are dumping way too much fuel.

Where do you plan on getting Greddy Fuel Pressure Guage? How much? I want to swap out my AFR Guage for this once I go with the big Turbo.

http://www.rx7store.net/index.asp?Pa...ROD&ProdID=180


That is where I was going to get my FP gauge. I already have the EGT, oil press, and boost gauge that match.


So I will be rewiring my pump and checking my fuel pressure and I'll see what I come up with. Thanks guys.