Fueling Issues

[enjoi.this]

I just installed my aeromotive fpr. When I turn up the fuel pressure with vac off its stable on the gauge until I get to around 40psi then it starts to jump around very irracticly.

Even at 6psi of boost the car begins to cut out and miss, like hitting a wall. under 3000rpm its OK but anywhere above it cuts out badly like its running out of fuel.

Any input would be appriciated since im supposed to go racing tommorow evening :aigo:

 

[jdub]

Why are you running FP so high? Do you have a wideband to confirm AFR when it cuts out?

Injector size?

Any ECU codes?

 

[enjoi.this]

Ive been running fp at around 36psi, I have been experimenting by turning pressure up and down. I dont have access to a welder to instal wideband until sunday

running 550's, afpr, j-tube removal, stock afm, walbro 255

What should I be running fp at for about 9 psi on stock turbo?

 

[jdub]

33-40 psi vac off
23-30 psi vac on <---this is the one that matters - it's the normal ops condition. 25-27 psi is what I usually see.

So, you are not running a MAFT Pro on speed density?

One more time, any codes? (I don't make a habit of asking questions more than once )

 

[enjoi.this]

Thats what Im running for fp with the vac off/on and no codes.

No maft-pro, decided on a different route once winter comes, delayed parts early in my build threw everything off course.

One thing I did was remove the mbc and it seemed to fix the problem. maybe I was hitting fuel cut? I have hit fc before when completely stock and this was not like it at all.

 

[grimreaper]

way to much fuel with the stock afm is what im expecting to see on the wideband...


crank the fuel pressure regulator up until you cant get a higher psi out of it. what does it read? i can easily hit 60psi on my walbro. At 23psi vac on i was still pig rich with lex/550s/walbro for comparison.

 

[enjoi.this]

way to much fuel with the stock afm is what im expecting to see on the wideband...


crank the fuel pressure regulator up until you cant get a higher psi out of it. what does it read? i can easily hit 60psi on my walbro. At 23psi vac on i was still pig rich with lex/550s/walbro for comparison.

You can hit 60 psi??

I tried cranking my aeromotive fpr up for testing and once I get to 40psi vac off the pressure gauge jumps from 25psi to 40psi constantly back and forth. Cant get any more pressure out of it.

One other test I did was check the fuel pump operation by jumping the diagnostic block pins. With the car off and the pins jumped I could turn the fp up to 50psi+. Maybe a 12 volt mod is needed for higher pressure?

 

[enjoi.this]

Installed the wideband today along with the lex AFM. Found out the autometre boost gauge i bought reads about 4psi lower then it should, big thanks to a member on here... :nono:

Replaced the shit gauge with a known good working one and turned the boost up to about 13-14 psi with a mbc. Now im still having the breaking up at around 4000 rpm but its moved up to the higher boost setting now. (fine at about 11 psi)

Wideband is reading a solid 10.3:1 a/f on closed loop and sometimes dipping into the 9's quickly. Im going to do the 12 volt fuel mod and re-adjust fuel pressure tommorow just to see if theres any change.

Current mods are 550's, afpr set at 34psi, lex afm and stock turbo. What are some things I could try to do some trouble shooting this??? :1zhelp:

 

[hvyman]

you want to be in the 11's for afr. 10.3 and 9's are way to low.

 

[jdub]

Installed the wideband today along with the lex AFM. Found out the autometre boost gauge i bought reads about 4psi lower then it should, big thanks to a member on here... :nono:

Replaced the shit gauge with a known good working one and turned the boost up to about 13-14 psi with a mbc. Now im still having the breaking up at around 4000 rpm but its moved up to the higher boost setting now. (fine at about 11 psi)

Wideband is reading a solid 10.3:1 a/f on closed loop and sometimes dipping into the 9's quickly. Im going to do the 12 volt fuel mod and re-adjust fuel pressure tommorow just to see if theres any change.

Current mods are 550's, afpr set at 34psi, lex afm and stock turbo. What are some things I could try to do some trouble shooting this??? :1zhelp:

If that is with the vac line connected it's too high. Set a 25-27 psi and see what it does.

 

[enjoi.this]

Its already said in above post's that its set to 34psi vac off and about 25 psi vac on

 

[jdub]

Its already said in above post's that its set to 34psi vac off and about 25 psi vac on

What are you smoking...you did not say anywhere previously specific vac on psi readings...why do you think I bolded the psi you posted? Your response to my post (#4) giving the TSRM FP ranges was this:

Thats what Im running for fp with the vac off/on and no codes.

You call that specific? And, what's the point of posting vac off numbers when the normal ops condition is vac on (like I said before).

Tell you what, vs getting into a pissing contest with you, I'll just exit the thread. I'm sure more knowledgeable guys here are willing to help you.

Good luck (with this attitude, you're going to need it).

 

[enjoi.this]

33-40 psi vac off
23-30 psi vac on <---this is the one that matters - it's the normal ops condition. 25-27 psi is what I usually see.

Thats what Im running for fp with the vac off/on and no codes.

I answered your previously posted question.

 

[toyotanos]

Yes you answered his question, but it's very hard to understand what you said, the way you said it. You should have included the specifics about what you were talking about.

I.E. Rather than saying "That's what I'm running for fp and no codes", you should have said something like:
"I'm running XXpsi vac on, and XXpsi vac off and there are no codes".

When trying to diagnose unknown problems, you need very specific readings so those people who specialize in this stuff can help you find out what's wrong (especially since they're not there in person). Communicating information efficiently can mean the differance between having your car running well again or having a money-sucking headache.

 

[enjoi.this]

^ Thanks tips..

Sorry for the confusion jdub, ill lay it out a little better next time for you.

Current status:
-34 psi vac off
-24 psi vac on
-No codes are present

When boosting to 13-14 psi is when the problem happens. At 10-11 psi it runs fine.

Its almost like hitting fuel cut, but not nearly as violent as when it was in stock form.

 

[isnms]

Wideband is reading a solid 10.3:1 a/f on closed loop...

Do you mean open loop? That's way to rich for closed loop.

Are you still on stock ecu? How does your VF look? (link in my sig)

 

[enjoi.this]

Do you mean open loop? That's way to rich for closed loop.

Are you still on stock ecu? How does your VF look? (link in my sig)

At full throttle the a/f is a 10.3:1

With throttle off its 14.7

Stock ecu

Im going to check out the VF today. wish I saw your sig earlier could have used some of that info!