Low BLM

[gnbrian]

I have been trying to figure this out. BL after warm-up has been average of 117, but is getting lower at cruise,110-99. I have now changed O2 sensor twice, even changed injectors from 50's to 009's and it seems to be worse. When rolling along in 3rd,accelerate and boost comes up and pop,but seems to be getting too much fuel, no knock at all. I have also changed ignition module and coil with new. What other sensor could be causing this,it BLM's are at 128 till warm up. Can fuel pressure regulator at all cause this. HELP !



TE-60, 212/212 cam, Walboro, Front mount, blocked egr, Bowling Green Intake, ported iron heads,62mm TB.

 

[TurboBuRick]

changed injectors from 50's to 009's and it seems to be worse.

Did you change chip when changing injectors

When rolling along in 3rd,accelerate and boost comes up and pop,

What do you mean by pop? intake backfire?

Can fuel pressure regulator at all cause this. HELP !

What is fuel preasure set at line off?

 

[gnbrian]

Yes chip was changed. When is was using the 50's I even had another chip made to count that out.

Yes intake pop

FP set at 42, tried lower also

 

[TurboBuRick]

Almost sounds like the coil pack or module. But you replaced them? Mabye a bad plug wire.

Post all readings from scanner.

 

[gnbrian]

You think the pop could be a plug wire? But what about the BL, would that affect that?

 

[TurboBuRick]

Pull the plugs. See if you find one that looks different that the others.
(black carbon) That will help you narrow it down. Find out if its one cylinder thats rich or all of them. A missing ignition or a bad injector will cause rich condition on one single cylinder.
Low blm's means rich
High mean laen
Good luck

 

[6=8]

I'm thinking fuel return line... They are just barely big enough for stock, then add mods including higher volume fuel pump, hot wire, and almost 20 years of use... and the fuel return line is suddenly becomes the regulator! When the fuel cant go back to the tank, there is only one other place it can go.

Mine finally deteriorated to the point I could set 43 PSI line off, even dial it a bit lower, but when I put the line on, if the pressure would not drop much.

I found all this out after a difficult struggle with CA smog inspection, and low BL# (85-90) at the test speeds of 15 and 25 MPH. My temp solution was to put an old fuel pump back in... It got me past the test, with BL#s around 112, but the real solution is fixing/replacing the return line so the regulator can do its job again.

I would also check your fuel PSI when you encounter this situation on the part throttle cruise to Power Enrichment. You might find that the better fuel pump, bigger injectors, and restricted fuel return line is actually working against you here as well.

 

[ThikStik]

If your cam is a flat tappett, I would suspect it.

 

[Quick6'n'-K.C.]

If your cam is a flat tappett, I would suspect it.

The last post was from MAY, why bring it up if the original poster isnt replying

BW

 

[gnbrian]

Why would you suspect in with a flat tappet cam? Been staying away from the car for awhile due to frustration. BL's seem to be a little better after changing out MAF to translator LS1. At least while under a load, not while in OD and locked up numbers are closer to 128.

 

[ThikStik]

Hey Quick 6in, he is alive.

Brian-It is almost always a cam when there is an intake pop. Have you seen that alot of people are losing cams?

Seal the border

 

[Quick6'n'-K.C.]

If it pops thru the intake, ive seen cars where the cam sensor isnt set correctly or is installed 180° out.
Car always will idle fine, but when bringing the boost up it will backfire thru the intake.

Caspers sells a awesome tool for setting the cam sensor

BW