lean out at 2600-2700

[7mgt45r]

put AN fitting on fuel rail for feed line and now car leans out only at 2600-2700 rpm's. its like a flat spot and then the car smooths out threw out the the rest of the rpm's. i have 680cc precision turbo injectors,-6 feed line,255 walboro, vpc/safc. the car only stumbles at that rpm. i tried adjusting fuel don't do no good.
pls can someone help me.

 

[figgie]

hmm
ever heard of the fuel resistor by pass mod? It is to make the fuel pump work at 100% all the time. Sarch for it and try it and see if the "lean out" goes away.

 

[7mgt45r]

hmm
ever heard of the fuel resistor by pass mod? It is to make the fuel pump work at 100% all the time. Sarch for it and try it and see if the "lean out" goes away.

do you know were i can find mod info

 

[jdub]

Do this to confirm it's the fuel pump resistor...it's simple. Just disconnect the resistor and jump the 2 prong connector on the harness side with a 12GA wire. You'll have to strip the ends, flatten with a hammer, and file the sides to fit the connector.

 

[7mgt45r]

do you know were i can find mod info

I've done the 12v modd. Io removed the relay and resistor.put jumper in 2,3 pins on relay connector and add 12v relay in back wired to fuel pump and still have issue. Help me out jdubb you the man.

 

[jdub]

Some more info please:

-What kind of acceleration we talking about? Pedal floored? Smooth, steady throttle into boost? Easy throttle?
What I need to know is does it do this all the time or what driving condition it does do it.
- Any codes?
- Do you have an AFPR?
- Fuel pressure at idle with the vac line connected? Does pressure increase when the vac line is removed?
- Where do you have timing set?

Are there any other mods with the ignition/fuel/air intake you're not listing?

 

[Poodles]

fuel pulsation dampener? Could also be the transition into boost.

 

[jdub]

He replaced the FPD with an AN fitting on the rail.

I was thinking the same thing though (power enrichment), or AFR correction during transition.

 

[7mgt45r]

Some more info please:

-What kind of acceleration we talking about? Pedal floored? Smooth, steady throttle into boost? Easy throttle?
What I need to know is does it do this all the time or what driving condition it does do it.
- Any codes?
- Do you have an AFPR?
- Fuel pressure at idle with the vac line connected? Does pressure increase when the vac line is removed?
- Where do you have timing set?

Are there any other mods with the ignition/fuel/air intake you're not listing?

under modrate acceleration,if i pressed more than 50% it would lean for about 3sec. and start bucking until you back off. No codes, yes aeromotive afpr,30psi with vac. line connected,when remove it doesn't increase,timing 10degrees top dead center. jdubb man i don't know whats going on didn't start until chg fitting on fuel rail. before had fuel feed going to the rail threw the old feed regulator

 

[7mgt45r]

fuel pulsation dampener? Could also be the transition into boost.

what is a fuel pulsation dampener? never heard of it. car runs fine below and above 2600-2700 rpm

 

[7mgt45r]

what is a fuel pulsation dampener? never heard of it. car runs fine below and above 2600-2700 rpm

and how do you stop it?

 

[jdub]

yes aeromotive afpr, 30psi with vac. line connected, when remove it doesn't increase,

Ok...pressure should increase when the vac line is removed, engine running. Check vac line routing to the high temp line pressure up VSV under the intake plenum. Make sure the vac lines are not blocked up. Make sure the VSV is plugged into the harness.

Here's how to check the VSV itself:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FI&P=116


Pretty sure you removed the fuel pulsation dampener when you put the AN fitting on at the rear of the fuel rail

 

[7mgt45r]

Ok...pressure should increase when the vac line is removed, engine running. Check vac line routing to the high temp line pressure up VSV under the intake plenum. Make sure the vac lines are not blocked up. Make sure the VSV is plugged into the harness.

Here's how to check the VSV itself:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FI&P=116


Pretty sure you removed the fuel pulsation dampener when you put the AN fitting on at the rear of the fuel rail

i removed the vsv.

 

[figgie]

i removed the vsv.

Well

there is your problem.

 

[7mgt45r]

Well

there is your problem.

so which one goes bck, aren't their 2 one for egr.

 

[jdub]

I really, really wish you guys would stop yanking vac lines, VSVs and whatever else off the motor without knowing what it does. Most of the time in order to "clean up the engine bay"...all this does is self induce a host of problems and for what? Don't get me started on the EGR...taking it off is not good either.

The high temp FP up VSV is the one on the lower front of the plenum. You can remove that VSV, but you may have hot start issues. If you do remove it, the AFPR MUST have a vac source. You either put a vac line between where the VSV used to connect to or you source vac from another place on the plenum. Otherwise, the AFPR is not going to increase fuel pressure as as rpm increases/boost psi rise.

 

[figgie]

I really, really wish you guys would stop yanking vac lines, VSVs and whatever else off the motor without knowing what it does. Most of the time in order to "clean up the engine bay"...all this does is self induce a host of problems and for what? Don't get me started on the EGR...taking it off is not good either.

You can remove that VSV, but you may have hot start issues. If you do remove it, the AFPR MUST have a vac source. You either put a vac line between where the VSV used to connect to or you source vac from another place on the plenum. Otherwise, the AFPR is not going to increase fuel pressure as as rpm increases/boost psi rise.

***joins the bashing of the lemming mentality***

I am still trying to figure out who in the name of started the yank the EGR non-sense. Because I want to smack them with my Kryptonite New York bike chain upside the head and then quarter them!

The sillyness of removing lines willy neely (not to be confused with the old members name of Will Neely) is just short of idiotic. Then the lack of reading the freaking TSRM which would answer 99% of all questions is another moment.

 

[7mgt45r]

I really, really wish you guys would stop yanking vac lines, VSVs and whatever else off the motor without knowing what it does. Most of the time in order to "clean up the engine bay"...all this does is self induce a host of problems and for what? Don't get me started on the EGR...taking it off is not good either.

The high temp FP up VSV is the one on the lower front of the plenum. You can remove that VSV, but you may have hot start issues. If you do remove it, the AFPR MUST have a vac source. You either put a vac line between where the VSV used to connect to or you source vac from another place on the plenum. Otherwise, the AFPR is not going to increase fuel pressure as as rpm increases/boost psi rise.

so you saying put egr valve bck on?

 

[7mgt45r]

***joins the bashing of the lemming mentality***

I am still trying to figure out who in the name of started the yank the EGR non-sense. Because I want to smack them with my Kryptonite New York bike chain upside the head and then quarter them!

The sillyness of removing lines willy neely (not to be confused with the old members name of Will Neely) is just short of idiotic. Then the lack of reading the freaking TSRM which would answer 99% of all questions is another moment.

man i didn't know, i was told to take the egr valve off because didn't need and thats why they make egr block offs

 

[figgie]

man i didn't know, i was told to take the egr valve off because didn't need and thats why they make egr block offs

Don't do things because people tell you to.

Firstly, research. See WHY people say to take it off. To gain power, that is a valid "excuse" but pointless as EGR does not effect power. What it will do is effect overall MPG ESPECIALLY at cruise!