Help me make my car run richer.

[Grandnat]

I have an LS1 MAF and 55/lbhr injectors and a walbro 340 FP.


The problem is that no matter what I do I run lean. BLM cell# 16 is at 100! but my O2s drop to the 690s before I have to let out of it.


I installed the 55s and the new walbro 340 in an attempt to help with the lean problem but it did not seem to help.

I only run 15 psi of boost and keep the fp around 40psi static.


The problem i am having is the exact same I had with the 009s and the ATR double pumper Fuel pump.....I have tried several chips and finally decided it was something wrong with the injectors or the FP sp I upgraded them both.


Fuel pressure rises as it should according to my FP gauge. (1psi of fuel fpr 1 psi of boost.)




I have GN1 heads and a comp 212/212 cam and PT54 turbo, but it even ran lean when I tried a TE44 still using the 55lb/hr injectors.


I am very very frustrated..... I am borrowing a good computer and hooking it up to my direct scan to see what it is doing this weekend.


Car is very lean...and VERY sluggish under boost.


I have already lost 3 headgaskets trying to chase down this problem and it is giving me a major headache.



max pulsewidth I see on DS is ~16ms


anyone had similar problems.


I will replace MAF and ECm and report back.....just looking for something obviouse I might have overlooked.

 

[BADINBLACK6]

Did you try upping the fuel pressure? It seems a little low, I don't think I ever ran anything under 43lbs static.HTH

 

[TurboJeff231]

Raise fuel pressure to 50 psi static and watch the fuel pressure at WOT. It should not drop....period. If you run 20 psi boost, you should have 70psi fuel pressure at WOT.

If you are using 55's did you upgrade the drivers in the ECM? 55's are low impedance injectors.

DR

 

[Eric Stage I]

Do you have a DS run you can make available?

Where is the 16ms at, what rpm? Does the pulsewidth drop as rpms rise?


Eric

 

[750H.P.V6]

Grandnat,

I think part of your problem could be your chip. Your low block learn value of 100 in cell 15 (the first cell is actually 0 so the last one is 15) will lean out your Power Enrichment fuel flow. The stored value in cell 15 is a trim for P/E fuel flow.

Some but not all chip makers use a patch to reset cell 15 to 128 when you go into P/E and then it will change back when you get out of P/E. If you don't have this patch then the car will be lean. Another possibility is that there just isn't enough pulse width commanded . Keep in mind you can run larger injectors but if the pulse width is shorter the overall fuel flow will be the same.

One thing you didn't mention is what your WOT fuel pressure is. Static fuel pressure really doesn't mean a thing if you don't maintain the proper differential pressure across the injector ie: static pressure + 1psi per lb boost minimum. I know you said you have an ATR double pumper but we've had problems with the pumps backing out of the y block in the tank.

Just some ideas. I hope they help.

Neal

 

[Grandnat]

First off, thanks for all the replies.


Neal I replaced my double pumper with a walbro 340.

And fuel pressure rises as it should from 40 to 55 under boost.

I also think that cell 15 is the problem and I will try another chip (prefferably one that locks cell 15 to 128)



I would like to add one more thing. when I am in it at WOT through 3rd gear the O2s drop to below 100mv.


I know that sounds crazy but it does.


I replaced my O2 with a brand new one.....same thinkg.

I also swapped with a known good ECM that has the drivers modified so it would work with my 55s and still got the same results.


the car seems to surge and boost climbs up tp ~20psi but the car never really moves.

I let out when knock gets to 4 degrees. (I am tired of changing head gaskets)

 

[c&cgn]

Are you using the TRanslator or T+ ? What chip are you using? Doesn't sound like you are using an Extender chip. I have always run at least 43 psi FP with my T+ regardless of what chip I had. The Extender instructions say to use 45psi so that is what I use now. Maybe you are pegging the MAF and an Extender chip may benefit you. Also, I would recommend getting an EGT gauge andstop using the stock O2 as a tuning guide. IMO the stock O2 is virtually useless.

 

[soonergn]

I'm kinda baffled here. I'm with BADINBLACK6 and TurboJeff231. The very first thing I would have done was turn the fuel pressure up to see what that does. That's why they make adjustable regulators.

 

[Grandnat]

Originally posted by soonergn
I'm kinda baffled here. I'm with BADINBLACK6 and TurboJeff231. The very first thing I would have done was turn the fuel pressure up to see what that does. That's why they make adjustable regulators.

Ok I should have said this earlier..... I have adjusted fuel pressure as high as 50psi and it only seems to make matters worse.

once the computer learns, it drops the BLM cell 15 value to 90 and the pulse width drops with it at WOT.

I have also lowered fuel pressure in an attempt to raise the requested WOT pulsewidths. It is currently at 40 since that is what I am trying at the moment.


I also have messed with the WOT settings on the translator ....currently it is at the richest WOT setting.



I will try a new chip that locks cell 15 ro 128............ then a known good MAF

 

[Grandnat]

TTT

 

[Brian Mc]

Maybe you should try tweaking the cam sensor, maybe it's timed wrong for the larger cam and fuel isn't spraying well.

Maybe you have a kinked fuel line somewhere restricting flow? blocked fuel filter? Low voltage to the pump? Low voltage to injectors? Exhaust leak feeging extra oxygen to the sensor like a crossover leak?

I tried.

 

[soonergn]

Maybe your boost gauge is not accurate. Any leaks in the line or connections would cause the guage to read lower than actual boost, making you THINK you are only running 15 lbs boost. However, you have stated that your fuel pressure rises from 40 to 55 psi and I would think it would increase more than that if you were overboosting. Just thought I'd throw that out there since I know absolutely nothing about chip settings.

 

[Crazi]

No expert but I also think the chip makes a difference here. What the chip says, the computer does. If the chip says you only need this much fuel, the computer is going to give that much plus/minus a certain amount. If you are seeing 100 at WOT, something is DEFINITELY wrong. Watch the BLM number as you are going to WOT and see if they go down or up as you press the pedal further. If they start to go down, I am not sure what that means but it is the exact opposite of what I have seen with my car.

What that tells me is the for some reason, the computer sees the need to PULL fuel out instead of add it. What chip are you using? Jim Testa helped my out immensely with a 19deg chip that feel as good as my 23deg chip. Give him a holler.