BLM thoughts

[headstrong3157]

I am currently having some BLM problems. At idle in open loop the BLM's are constant at 129 once it gets warmed up and switches to closed loop the BLM's peg out at 160. A couple of days ago I drove it for a short trip and under throttle the BLM's are around 129-134 but sitting at idle at a light they peg back out to 160. I recently switched to an Extender Extreme chip but before i unplugged the ECM to switch chips it had set an error code 13. So im thinking that its 02 sensor going bad thats causing me the problems. I am going to attach a word file that has my entire set-up on it and if I should post the rest of my scanmaster numbers at idle I will do it tonight when I get home from work. Any thoughts would be appreciated, I havent done the vaccum leak chase on it yet but will if I have to also could be a cracked header. Thanks in advance for any information.

 

[Jerryl]

.......... At idle in open loop the BLM's are constant at 129 once it gets warmed up and switches to closed loop the BLM's peg out at 160. A couple of days ago I drove it for a short trip and under throttle the BLM's are around 129-134 but sitting at idle at a light they peg back out to 160. I recently switched to an Extender Extreme chip but before i unplugged the ECM to switch chips it had set an error code 13. So im thinking that its 02 sensor going bad thats causing me the problems. .......... I havent done the vaccum leak chase on it yet but will if I have to also could be a cracked header.

You are on the right track and answered your own question.
Vacuum leaks, cracked header, bad O2 and incorrect extender settings will all get you to a high BLM. Also, verify your FP under load.

 

[headstrong3157]

Yeah I had the ideas on what causes the BLM's to peg out like that just wondering if replacing the O2 sensor would be the best place to start with that error code being thrown. I know its an easy place to start at least. I went ahead and ordered a new Denso today and will start there I can only cross my fingers that it will be that easy. Thanks for any other input

 

[2 QK 4 U]

I'm having same problem. I have a commander chip, same as extender but for stock maf.

A new denso didn't make a difference for me. I've chased vacuum system and found nothing. Mine get up to 156 in closed loop.

 

[headstrong3157]

Well if the new denso doesnt help then i will block off the vacuum and check it to see if its a vacuum leak or bad maf or cracked header. Im just hoping that with the code being thrown that it will be that easy of a fix. If its not that it will ruin a weekend or two for me

 

[headstrong3157]

Here is an update on the high BLM situation. I had a lot of vacuum leaks those are all fixed now and EGR is completely blocked off. Leaky header and a leak at the crossover flange both of those are fixed. My BLM is now sitting at 144 at idle so I have made some progress. My next plan is to have my buddy bring his MAF sensor over and put it on mine and see if it changes anything if the MAF doesnt help the situation im going to relocate the MAF to the throttle body to see if the intake pipes are leaking somewhere. I listened to the injectors tonight with a stethoscope and all seem to be ticking the same. Any other ideas to check before I start checking the TB gaskets, plenum, intake, IAC gasket, etc etc. Thanks for any suggestions and thanks for all the great answers in previous threads where I have gotten all the info on checking for problems.

 

[turbobose13]

always start with the cheapest thing first and go from there.

 

[mikec1969]

Have you tried moving the base setting on your translator to 1. Should lower your BL's. I fought a slightly high BL # and ended up checking my PCV valve by disconnecting it from the vacuum line and capping off the source. Bl's are now perfect. I'm going to replace the PCV, but if BL's start acting up again I'm going to delete it altogether. The motor has breathers on both valve covers and I don't drive the car much.

 

[headstrong3157]

Ok its time for an update on my high blm situation. I now have them down to 142 at idle. I tried changing the translator setting to 1 to make it run rich but it made it run too rich everywhere else in the rpm range but fixed the idle blm problem so I went back to the normal setting and started looking for more issues. I am going to order a new 3 1/2" MAF pipe to replace the one I have now that is kind of pieced together so that will be good and new and sealed tight. A new problem that I discovered today is that the throttle body seals are leaking so Im not for sure what to do for this problem. I have no idea where to get seals at for it or anything. Does anyone think upgrading to a 70mm throttle body, plenum, and power plate is worth it. My car has run a best 1/4 time of 10.78 @ 125. I know a 70mm is one of the last things to do just didnt know if the upgrade would be worth it or just get the seals on my 62mm fixed. Thanks for any info all help is appreciated.

 

[87geeinn]

If your throttle seals are leaking then it might be a good idea to go to www.throttlebodys.com. You would kind of be killing two birds with one stone; getting a new upgraded 62mm throttle body along with all new seals.

 

[REGALTURBO]

Two of the best pieces of equiptment I invested in was a vacume pressure checking device and a wide band O2 sensor. Fairly inexpensive and my car never ran better.

 

[jdpolzin]

How does your Vac Pressure tester work? I am having BL problems as well and if they aren't too expensive, it would help. Just wondering how it works? Thanks ----Jeremy

 

[Lee_Burough]

Somebody on this board does these throttle body repairs, and bores them out too....Do a search and see what pops up.

 

[REGALTURBO]

My Vacume pressure tester works very simple. It came with a variety of tips for many different size hoses or fittings. All you do is pull a vacume line, attach it to the pressure tester and start pumping air into it. You don`t really need alot of pressure but before you know it you will hear hissing, whistles and squeaks from places you never figured you`d hear it. Replace the lines, connectors or 1-way check valves that aren`t working. You will see a noticable difference in idle and drivability. Alot of people try to lean the idle way down before they fix the vacume leak and that just band-aids the problem. For about $40-$50 its well worth it.