Still having a BLM issue

[rob350]

Well I finally got my passenger side header off, which was cracked pretty bad, and had it welded. I replaced the oxygen sensor while I was at it. I fired up the car and let it run for awhile and it seemed like it was running pretty good. I finally went ahead and plugged my laptop in. My BLM was around 109 at a hot idle and it was throwing a code 45. My previous problem was the BLM pegged at 150. The car also seemed to be running better than before. I decided to disconnect the battery and reset the computer (again). This time the BLM slowly creeped up to 150 again. The car also appeared to be running how it always did. Also, When I unplug my MAF, the car will run for a second or two then die unless I keep my foot on the gas. I thought the car was suppose to run of the default parameters. I'm not sure where to look next. My car is stock, with a 87 ECM, an authentic 87 MAF and a stock 87 EPROM. The car also ran like this when I had all my stock 85 components it it.


Thanks,

Rob

 

[Jerryl]

Sounds like you still have a vacuum leak.
Post your numbers for:
FP - static
IAC - Idle
TPS - Ignition on, car not running
MAF - Idle
RPM - Idle

 

[84GNGary]

Sounds like you still have a vacuum leak.
Post your numbers for:
FP - static
IAC - Idle
TPS - Ignition on, car not running
MAF - Idle
RPM - Idle

Yep, my aftermarket pcv valve drove me crazy with high blm's. Make sure you have new AC Delco only. You can also spray some carb cleaner on your vac lines and connections while the engine is idling and listen for it to bog down slightly when you hit a leak.

 

[rob350]

Sounds like you still have a vacuum leak.
Post your numbers for:
FP - static
IAC - Idle
TPS - Ignition on, car not running
MAF - Idle
RPM - Idle

FP-Static: 38
IAC: 26
TPS: .43
MAF- 6
RPM Idle: 675

 

[Jerryl]

FP-Static: 38
IAC: 26
TPS: .43
MAF- 6
RPM Idle: 675

What chip are you running?
Try to adjust:
FP-Static: 43 (Most chip writers' recomendation)
IAC: 10-20

 

[rob350]

What chip are you running?
Try to adjust:
FP-Static: 43 (Most chip writers' recomendation)
IAC: 10-20

I have the stock 87 EPROM. I have the stock FP regulator too. I forgot to mention that the car surges on a cold start-up until it warms up.

 

[Jerryl]

I have the stock 87 EPROM. I have the stock FP regulator too. I forgot to mention that the car surges on a cold start-up until it warms up.

I am not sure how well a stock 87 Chip performs on a stock HA.
Guess "you do want the FP around 37" with the stock IC chip.

Are you using the HA MAF? Do you have an 87 MAF to try?
What are the O2's during the surge?
(I am not thinking real clear today )

 

[rob350]

I am not sure how well a stock 87 Chip performs on a stock HA.
Guess "you do want the FP around 37" with the stock IC chip.

Are you using the HA MAF? Do you have an 87 MAF to try?
What are the O2's during the surge?
(I am not thinking real clear today )

I got an 87 MAF.

 

[84GNGary]

I ran a stock 87 chip in my car before with no problems that I can remember. The only thing is the MAT sensor code if you don't have one.
High blm's means the engine is indicating a lean condition and wants to add fuel. This is no good because you can wash down the cylinders. It's usually from air entering the engine somewhere without being accounted for by the maf. If you still have stock acordion style air intake make sure its not split anywhere, also check throttle body plate, vac block on throttle body and pcv valve and it's engine grommet.

If all that is good you must have a vac leak somewhere else, try this process of elimination. With the car idling and your scan tool monitoring your blm's disconnect one vac line at a time and plug it at the vac source. If your blms start to go down you just narrowed down where a leak is now find out what is on that line and find your leak. Keep doing this for all your lines. If the blms don't change when it's removed put the line back on and move to the next one. I found my faulty pcv valve this way.

 

[84GNGary]

Also how is the drivers side header ? they usually crack in the valley between the 2 back cylinders. Did you torque the headers down properly and did you copper rtv sealent on them ? The other thing too is the headers should be bolted to solid piece of steel while welding to prevent warping of the flanges.

Don't worry about the pcv valve grommet, I was thinking about something else.

 

[rob350]

Also how is the drivers side header ? they usually crack in the valley between the 2 back cylinders. Did you torque the headers down properly and did you copper rtv sealent on them ? The other thing too is the headers should be bolted to solid piece of steel while welding to prevent warping of the flanges.

Don't worry about the pcv valve grommet, I was thinking about something else.

I had the drivers side welded last fall. I did torque them down properly but did not use RTV on them.

 

[rob350]

I'm running the stock 87 chip in my 87 ECM. Could this in any way make my BLMS go up? I'm still trying to hunt this down. What are all possibly places I could have a vacuum leak?

Thanks,

Rob

 

[84GNGary]

Did you do everything I suggested above? Could you put back in your stock ecm & maf then see what your blm's are ?

 

[rob350]

I only have WINALDL. I'll have to see if that reads the 85 ECM.

 

[84GNGary]

I only have WINALDL. I'll have to see if that reads the 85 ECM.

I remember reading that it only works on 86/87 ecm's. You are going to need Turbo Link or an OTC 4000. Are there any Turbo Buick clubs in your area, someone is bound to have an old Turbo Link setup that they can hook up to your car. Here is what I went through after converting the ecm, I just finally got my knock issues fixed.GN and T-Type Performance Enthusiasts (GNTTYPE) Forums - 84 BLM/ Engine Temp Question.

Why don't you order a Turbo Tweak chip for your car then you know it right and it's one thing you can eliminate. But if your blm's are high because of a leak it's not going to help.

 

[rob350]

Well this is weird. I put my stock 85 MAF back in just for giggles and now my BLMS are around 130. It appears that the car is running a ton better. Is my 87 MAF crap?


Rob

 

[rob350]

I forgot to ask if it was ok to use an 85 MAF with and 87 ECM? Or is the 85 MAF making false readings to make my BLMS shoot down? I put my 87 MAF back in and the BLMS climbed up to 150 again.

 

[84GNGary]

I forgot to ask if it was ok to use an 85 MAF with and 87 ECM? Or is the 85 MAF making false readings to make my BLMS shoot down? I put my 87 MAF back in and the BLMS climbed up to 150 again.

I remember reading somewhere that they are not interchangeable because of the calibration. What are your maf readings on both of them ? At idle they should be around 6 g/sec.
What have you done or tested so far ?

 

[rob350]

If I remember correctly, my 85 MAF is showing 6-7 g's at idle, and my BLMS were about 130. I would put my 87 MAF in and get the same amount of g's but a BLM of 150. I'll check it again today after work.

 

[84GNGary]

Found this in the IC section, may help a little.
http://www.turbobuick.com/forums/general-turbo-buick-tech/226226-high-blms-vs-cracked-header-vs-fuel-pressure.html