BLM 142, Slow turbo spool and 10:1 AFR boosting, need input

[excobraguy]

OK, so after taking my car to the track recently, I am VERY disappointed in the results. One run actually cut a 3.0 second 60' time, yes 3.0!!!!!! Totally a dog taking off...........

Here's what I have noticed and what I have tried. I'm looking for input on what to fix and what to leave alone, adjust, tweak etc.....

My setup:
a TA58 turbo, 60lb injectors, TH style downpipe (it is cracked at one of the weld seams), stock intercooler, stock maf, KN filter, M/T drag radials, stock headers (unknown if there are leaks), no cat runs out to dual exhaust. Accufab FPR set to 43 lbs, Alcohol chip from Turbo tweak (No Alky injection yet), AEM A/F gauge, Scanmaster 2.1, Manual transbrake, RJC boost controller with wastegate turned all the way in. Running 23 lbs of boost on 110 VP racing fuel

What I've noticed at idle:
At idle the car's A/F ratio will lean out and go above the 17.9:1 mark and go to -- -- on the gauge. Revving the engine will bring it into the 14.5:1 range but then goes back to the -- -- with no revving.
When I installed the new Alky chip BLM's stayed at 128 but then went to 142 like the old chip TT 5.7 did. Cruising the BLM's go down.

What I noticed when using the trans brake and launching:
Builds boost VERY VERY SLOWLY!
When it finally hits 10 lbs, after like a 10 second wait, the AEM A/F gauge is showing 10:1 AFR and would go lower I bet but 10:1 is the lowest reading it can go, car is running pig rich trying to boost!
When shifting from 1 to 2 off the transbrake it bogs and then finally boost will build and it grabs and moves out good.
Fuel pressure did build up with the boost at a 1:1 ratio.

What I tried and the results:
So after reading that running rich slows down boost I adjusted my FPR to run leaner. This did in fact help the boost spool but after spooling and then launching I would hit like 400-500 mv on the Scanmaster o2 readings and some 15:1's on the AEM, definitely not safe.

So my questions
OK, if you read all this you saw that I said I had a cracked downpipe, could this be the cause of the high BLM's I am seeing at idle?
Could a cracked header with the cracked downpipe be causing a pig rich condition when trying to boost? Again, 10:1 is where it is when launching and taking off on the transbrake.
How much of it could be the chip? Keep in mind my old chip did the exact same thing, 142 BLMS and slow spooling.
Why is it a lot of guys with similar problems have the same BLM of 142??? I've seen it a lot.
Anyone have any input on this?
I noticed my fuel pressure bleeds down to 0 in less than 4 hrs, is this normal? Should it hold the pressure at the line?

Things I am going to check and try based on what I've read:
The puck sealing in the wastegate, no visible leaks in this area.
header cracks, smoke test???? or take them off for inspection?

Any input is greatly appreciated, thanks in advance!!!!!!

 

[buickGN3:16]

Exhaust leaks do effect blm's. Cracks, gaskets, ect.. i had blm's @ 142 then i found a 1/8" hole someone drilled in my header collector & i seal that hole off & my blm's went down to 135ish!

 

[Bigjsn250]

What converter?

Why are you changing the fp, you should be using the chip to make adjustments.

I would never be on a transbrake for 10 secs.

Yes cracks pre turbo cause the computer to add fuel.

What is the vacuum reading at idle?

 

[buickGN3:16]

Fuel pressure fall off could be fpr diaphram, fp check valve , injector sticking open, ect! if it dosent cause the car to be hard to start then its most likely not a problem where fuel is leaking down in the cylinders, probly in the tank area. Just some thoughts

 

[excobraguy]

What converter?

Why are you changing the fp, you should be using the chip to make adjustments.

I would never be on a transbrake for 10 secs.

Yes cracks pre turbo cause the computer to add fuel.

What is the vacuum reading at idle?

Has stock converter. The FPR was adjusted to just check if the fueling was affecting the afr at launch, it was. I did it as a quick test to rule out possible turbo issue or something else, wasn't planning on leaving it there. So I am pretty sure my problem is the BLMs being 142 and getting too much fuel in lower rpms. Haven't checked vacuum.

 

[Bigjsn250]

I just noticed you have an alky chip but no alky system???

 

[Eric Stage I]

A high BLM means the computer thinks its lean and is adding fuel. If you are using leaded race fuel, the O2 sensor might be dead causing the computer to add fuel. You might try replacing the stock O2 sensor, and possibly the wideband sensor. Downpipe won't affect the stock O2 since its before the turbo.

If that's not it, then it could be a MAF problem causing it to be actually lean, and the computer is adding fuel to compensate.

Also make sure the injectors and chip match. In other words, I only make 60lb chips for Siemens hi-z 60's, so make sure that's what they are (Racetronix 63's and PTE 65's are the same thing as 60's). (if you bought them from me, then I know they're right)

If you don't run alky, it won't affect the BLM. It will just be leaner up above 15psi, so you might have to add WOT fuel depending on the boost level.

Eric

 

[Eric Stage I]

Almost forgot, high BLM could also be a vacuum leak. In other words, air is getting into the motor that has not passed through the MAF, which will throw off the fuel calculation. Check for vac leaks, or bad PCV valve.

 

[excobraguy]

A high BLM means the computer thinks its lean and is adding fuel. If you are using leaded race fuel, the O2 sensor might be dead causing the computer to add fuel. You might try replacing the stock O2 sensor, and possibly the wideband sensor. Downpipe won't affect the stock O2 since its before the turbo.

If that's not it, then it could be a MAF problem causing it to be actually lean, and the computer is adding fuel to compensate.

Also make sure the injectors and chip match. In other words, I only make 60lb chips for Siemens hi-z 60's, so make sure that's what they are (Racetronix 63's and PTE 65's are the same thing as 60's). (if you bought them from me, then I know they're right)

If you don't run alky, it won't affect the BLM. It will just be leaner up above 15psi, so you might have to add WOT fuel depending on the boost level.

Eric

Hey Eric,
Thanks for the reply. The chip I have is the one I just ordered the from you, James Cassidy. I thought about the 02 and ordered two of the Denso's that were just delivered today. So I will try replacing one when i get home from work. I supplied the injector part numbers when i ordered my chip. hopefully it's the right ones. The injectors were already in the car. And like I said earlier though, the 5.7 chip i had in had the same results.
My o2's up high seem fine and I rarely had any knock at all.......... .04 at the most. I will also check the maf............

 

[excobraguy]

I just noticed you have an alky chip but no alky system???

And???????

 

[StageII86]

Sounds like there is good potential for the injectors being wrong.

 

[excobraguy]

just replaced o2 sensor with new Denso o2 sensor, no change....still at 142

 

[excobraguy]

A high BLM means the computer thinks its lean and is adding fuel. If you are using leaded race fuel, the O2 sensor might be dead causing the computer to add fuel. You might try replacing the stock O2 sensor, and possibly the wideband sensor. Downpipe won't affect the stock O2 since its before the turbo.

If that's not it, then it could be a MAF problem causing it to be actually lean, and the computer is adding fuel to compensate.

Also make sure the injectors and chip match. In other words, I only make 60lb chips for Siemens hi-z 60's, so make sure that's what they are (Racetronix 63's and PTE 65's are the same thing as 60's). (if you bought them from me, then I know they're right)

If you don't run alky, it won't affect the BLM. It will just be leaner up above 15psi, so you might have to add WOT fuel depending on the boost level.

Eric

Eric,

My injectors have B161A06747 on the body and 07961 on the tops.............it looks like those numbers anyway, might be wrong but that's what they look like. Do these numbers look right????

 

[Eric Stage I]

The injector part# is probably 107961, so that is correct for the 60's, and the chip is made for those injectors.

 

[excobraguy]

found bad exhaust leak on rear passenger side header. I'm assuming this is what's causing the boost leak and high blms at idle as well as the 10:1 af ratio. My headers have gaskets. I've seen people say not to use gaskets and then those that say do use gaskets..........thoughts on this?

 

[excobraguy]

The injector part# is probably 107961, so that is correct for the 60's, and the chip is made for those injectors.

Thanks for confirming

 

[Ed Valvo]

Header leaks hurt spool. What RPM are you launching at? Tight converter will make it come out of the hole like a pig.

 

[TurboDave]

Why are you changing the fp, you should be using the chip to make adjustments.

Agreed!!!! Keep your dick skinners off the FPR! Make your fuel adjustments in the chip. With modern chips/electronics, the only reason for an adjustable FPR is to set up initial base fuel pressure.

 

[buickGN3:16]

found bad exhaust leak on rear passenger side header. I'm assuming this is what's causing the boost leak and high blms at idle as well as the 10:1 af ratio. My headers have gaskets. I've seen people say not to use gaskets and then those that say do use gaskets..........thoughts on this?

i have copper gaskets behind my header flanges, with or without dont matter as long as theres no leaking going on imo.

 

[excobraguy]

Agreed!!!! Keep your dick skinners off the FPR! Make your fuel adjustments in the chip. With modern chips/electronics, the only reason for an adjustable FPR is to set up initial base fuel pressure.

Look guys, did you not read my post. This was done as a quick test to see if I had a fueling issue, which I do. Not sure what is causing it yet but again it was a quick test to see if the fueling was causing the slow spoolup. I'm also looking for comments to try and help find my problem.