running too rich or too lean?

[deviousgst]

i recently got my motor rebuilt(forged Je pistons, eagle rods and cometic gaskets)(my mods are up to date) and since then its been cutting out wen i hit WOT. My set boost is at 20psi. Wen im like at 3krpms i hit wot and drags(hesitates) up to 10psi and anything after that it starts to cut out.
i havent got it tuned yet since i got it rebuilt can this be the problem. or is it jst running to rich or too lean...
thanks in advance

 

[PIMking]

Do you have any type of logger? that would help a ton!

 

[rstare]

I would say your running too lean, just cause you have no fuel mods, so you have no way to add the extra fuel for all the extra air your getting.

 

[deviousgst]

I would say your running too lean, just cause you have no fuel mods, so you have no way to add the extra fuel for all the extra air your getting.

what do u mean by fuel mods, like a fuel pressure regulator or like injectors(i got 660injectors)

 

[rstare]

How about a fuel pump? I didnt see anything about injectors or a fuel pump in your profile.

 

[deviousgst]

How about a fuel pump? I didnt see anything about injectors or a fuel pump in your profile.

welll i know i have 660 injectors but im not sure about the fuel pump. the guy i bought it off from never told me about the fuel pump.

 

[rstare]

You probably dont have one then. Your going to need a 190lph fuel pump, at the minimum. If you get a 255 you will need a afpr.

 

[deviousgst]

You probably dont have one then. Your going to need a 190lph fuel pump, at the minimum. If you get a 255 you will need a afpr.

how much fuel pressure should a stock 97 gst turbo eclipse have

 

[rstare]

43psi

 

[jerry_69]

You probably dont have one then. Your going to need a 190lph fuel pump, at the minimum. If you get a 255 you will need a afpr.

+1

 

[deviousgst]

43psi

but before i got my car rebuilt. it use to run bad ass ...but the shop told me that i just need a tune and it will be back how it was...is this correct

 

[rstare]

Your stock fuel pump wont push enough fuel to your injectors once you start running about 16psi. You said you are running 20psi.
As I previously stated your not getting enough fuel with all that extra air your getting from the 20psi. You need a bigger pump, simple as that. If you turn down the boost I bet your car will run just fine. So either get a fuel pump (190lph, at minimum, or a 255, but then you need a afpr) or turn down the boost.

Edit: You cant tune what you dont have. You dont have enough fuel and you cant make the pump push more by tuning.

 

[deviousgst]

Your stock fuel pump wont push enough fuel to your injectors once you start running about 16psi. You said you are running 20psi.
As I previously stated your not getting enough fuel with all that extra air your getting from the 20psi. You need a bigger pump, simple as that. If you turn down the boost I bet your car will run just fine. So either get a fuel pump (190lph, at minimum, or a 255, but then you need a afpr) or turn down the boost.

Edit: You cant tune what you dont have. You dont have enough fuel and you cant make the pump push more by tuning.

so how is it that when i first had my car i was able to boost 20psi no problem and i even tried 26psi and it ran great(no hesitation or nothing)..But since the rebuilt its been running like how it is now

 

[4Motion4g63]

why did you do the motor rebuild, If it was running great?

Have you done a boost leak check yet...

 

[deviousgst]

why did you do the motor rebuild, If it was running great?

Have you done a boost leak check yet...

i rebuilt it because i had blown one of the pistons

 

[rstare]

How much boost were you running before you rebuilt it.

Either way, you NEED a fuel pump, the stock one is simply not going to push enough fuel.
Pull your pump and see if its the OEM or a aftermarket one.

 

[rEclipserGST]

You should ###### get an SAFC of some sort. Ive heard of people pushing the limits of the stock fuel system... 18 psi with no fuel cut. But yea, 1st thing you should of got was the Walbro Fuel Pump before injectors. 450's can go along way.

 

[ekstrom133]

I am having the same problem with a 255 welbro pump and 550cc injectors. Doesn't cut out in first gear but at about 4,000 rpms in 2nd 3rd adn 4th gear it cuts out and hesitates..im running 18 psi

 

[rEclipserGST]

I am having the same problem with a 255 welbro pump and 550cc injectors. Doesn't cut out in first gear but at about 4,000 rpms in 2nd 3rd adn 4th gear it cuts out and hesitates..im running 18 psi

Yea, your going to need the following with an upgrade Fuel Pump & Bigger Injectors:

Adjustable Fuel Pressure Regulator
Air/Fuel Controller

AFPR to adjust the psi of fuel
AFC to controller the injectors pulse rate and compensate for fuel usage

 

[ekstrom133]

I just put in a wideband and have a SAFC and an hour after i got it tuned and was running and spooling great then it started cutting out and hesistating

 

[rstare]

With a 255 pump, you need a afpr. Otherwise the pump will make you run rich.

 

[tristanmb81]

did you check for bost leaks?

 

[ekstrom133]

I have a fuel pump regulator. i might be running a little lean if anything but i have had people look at it and they don't think its a fuel cut ### it only hesistates but i dont think its a misfire

 

[ekstrom133]

no i have not checked for boost leaks yet

 

[rstare]

What exactly does this "fuel pump regulator" do?
A AFPR is what your looking for, that way you can control your fuel pressure so your not getting too much fuel.
Read the Tech section people.