Had a question about what it is that is causing BLM to be........

[Nascar83Fan]

sitting stuck on 142, but INT and other numbers are looking ok. Int is at 128, BLM doesn't change at all from 142 at any rpm. Would that be O2 sensor causing that or is that a PCV or what? I have a 1987 Turbo T astro-roof and there's no smoking anywhere & she is running a bit rich with the BLM being where it is if i recall correctly. What do you guys think?

 

[CGASTON]

So do you have a scanmaster? Post all your readings? What is the fuel pressure (with and without vacuum)? TPS? O2? Have you done any work to it at all lately? It can be one of few things. Need all info to help better.

 

[Nascar83Fan]

Yeah i have a scanmaster, i'll pull the numbers off everything in a bit when i get into her in a little bit later today.

 

[dennisL]

It would also help if we knew which chip and maf (stock, LT1, etc).

 

[TurboDave]

sitting stuck on 142, but INT and other numbers are looking ok. Int is at 128, BLM doesn't change at all from 142 at any rpm. Would that be O2 sensor causing that or is that a PCV or what? I have a 1987 Turbo T astro-roof and there's no smoking anywhere & she is running a bit rich with the BLM being where it is if i recall correctly. What do you guys think?

142 isn't so bad but maybe there's something that we'll find in the tune that may be causing it. However.......

Just so you understand the relationship between INT and BLM and why the INT are normal and the BLM are a little off is as follows. In the simplest of terms, the INT is what drives the BLM. So the INT on this case is happy with were the BLM is at so it sits at a more normal value. Now, if something were to happen that would indicate that the BLM needed to go higher, the FIRST thing that would happen is the INT would go high and stay there while the BLM start incramenting upward. As the BLM got to a value that makes the ECM happy the INT would come back to a more normal level.
The further the BLM has to move (the worse the air fuel imbalance is), the further off center the INT will move to force the BLM to the level needed.

Clear as mud?

 

[Nascar83Fan]

IT has a turbo tweak 5.6 chip and it has a MAF that is a factory replacement. The INT also decides to move alittle bit and it's causing the car to run alittle richer than it should be, which is causing it to perform alittle slower than when the car wasn't reading over 130 for both BLM and INT along with the O2's are reading alittle lower than they should be. I am thinking the IAC is in need to be replaced since a mechanic had pulled it & said it was pretty dirty but he cleaned up the IAC a bit which seemed to help some. I'm also considering the PCV or O2 sensor, not so sure that they arent actually starting to go bad as i am not real sure the age of them when i had gotten the car from the previous owner. It's probably time to change those since they seem to be parts that on our cars like to go bad in a shorter period of time than most cars. As there's no leaks that could be found on any of the vaccuum lines, so with no error codes it's starting to look like it's one of those that is on the way out. I'm working on collecting numbers off my scanmaster and later today i should have those posted which should make it easier for you all to point me in the right direction. Thanks for the replies so far and will get the readings up as soon as possible today.

 

[Nascar83Fan]

Well in gear sitting at lights she jumps upto 140's to 150's int with occassional 160 and BL jumps to 142, once i start moving the int's only bounce from 112 to 128ish and BL floats around 128 to 136 with bounces to 142. Tps at idle is 0.42 , in gear the idle drops down to 625-650 at times sometimes as low as 500. While in park 750 to 800 is the idle. From what i can see since it's idling alittle rough but no knock, it seems like that is an iac issue possibly since once i get around 900 rpm or so she is fine so. I wished i lived closer to any of the turbo buick owners here in texas, be easier for them to see what she does.

 

[Ttype6]

Well in gear sitting at lights she jumps upto 140's to 150's int with occassional 160 and BL jumps to 142, once i start moving the int's only bounce from 112 to 128ish and BL floats around 128 to 136 with bounces to 142. Tps at idle is 0.42 , in gear the idle drops down to 625-650 at times sometimes as low as 500. While in park 750 to 800 is the idle. From what i can see since it's idling alittle rough but no knock, it seems like that is an iac issue possibly since once i get around 900 rpm or so she is fine so. I wished i lived closer to any of the turbo buick owners here in texas, be easier for them to see what she does.

What are the IAC numbers?

 

[Nascar83Fan]

Well i think i figured out the problem, i'll be dang if the clamps aint holding the rubber adapter between the intercooler pipe and intake. I feel pretty dang stupid right about now, i figured out something was up when i kept hearing tons of boost blow off under the hood, the mechanic must notmof gotten it on there tight. Rather annoying to find out that it was that when it's dark outside.

 

[Nascar83Fan]

After replacing part of the vaccuum line which runs under the AC system near the firewall on passenger side that feeds off the two-way valve that the EGR is also connected to, she is idling alittle better. It was cracked near the two-way valve and because it was somewhat behind the coil pack, it wasnt easy to see without looking really hard. So after a trip to o'reilly's for some vaccuum emission line, a rubber vaccuum line connect and a few minutes of my time in the parking lot repaired it then started her up. She's been doing better since, she is still alittle richer than she should be which means i have something going on in the tune possibly or something is sticking somewhere. I have no codes and doesn't seem to be lacking power, i in some ways wished these cars were OBDII then in real time i could see some things that the scanmaster itself can't show which would make it so much easier to know why i'm running a bit richer than i use to be. Alittle frustrating, since it is somewhat eatting into the fuel mileage she would get with there being a bit too rich going on.

 

[Ttype6]

After replacing part of the vaccuum line which runs under the AC system near the firewall on passenger side that feeds off the two-way valve that the EGR is also connected to, she is idling alittle better. It was cracked near the two-way valve and because it was somewhat behind the coil pack, it wasnt easy to see without looking really hard. So after a trip to o'reilly's for some vaccuum emission line, a rubber vaccuum line connect and a few minutes of my time in the parking lot repaired it then started her up. She's been doing better since, she is still alittle richer than she should be which means i have something going on in the tune possibly or something is sticking somewhere. I have no codes and doesn't seem to be lacking power, i in some ways wished these cars were OBDII then in real time i could see some things that the scanmaster itself can't show which would make it so much easier to know why i'm running a bit richer than i use to be. Alittle frustrating, since it is somewhat eatting into the fuel mileage she would get with there being a bit too rich going on.

IAC number at idle?
BL number at idle?