Help!! Please!! High BLM 150!! Cant find problem, or pass emissions

[Thunder]

Well, I have a problem... I can't pass the emission test... probably due to my high BLM at idle, pegged at 150. Off idle, the BLM come down off of 150, to 145ish. I am running my JL emission chip for my delphi 50's from pte. Spark plugs have been changed, new AC 44's. Have good spark at all cylinders(also tried my spare known good coil pak/module). All injectors sound like they are working (used the stethescope) and those that could be unplugged easily, do make a difference for the worse, in the already poor idle. Unplugging the maf brought the BLM, at idle, to the 130 range!! I thought I had found the problem, and took out my maf x-lator and 3" lt1 maf, set to the 3" setting, and same problem!! I have checked for vacuum leaks w/ starting fluid, carb cleaner, and with the hose on my stethescope. I have even removed the EGR, and replaced with a coating of high temp RTV to eliminate that problem area. I am stumped on this!! Any help would be greatly appreciated.

TIA

 

[Chris Taylor]

Turn the fuel pres. down to pass the test, and turn it back up.

 

[WarpSpeed]

Do you have an AC Delco O2 sensor, and if so, how old is it?
Also, any exhaust leaks before the turbo?

 

[Thunder]

Chris Taylor- Thanks for the tip, I really don't need to pass the test now. It is not my daily driver, and I can just have the plates suspended till I fix the real problem, and test at that point.

Warpspeed- Yes, I also changed the o2 from a 3 month old AC to a new AC with no change at all. I do have a very tiny exhaust leak. On the tube off of #2 cylinder (a touch to much on the port work). I dont think the leak is causing such a large problem, esp since it all evens out with the maf unplugged.

thanks

 

[2QUIK6]

Bad or incorrect PCV valve? I had BLMs at idle in the 140's when mine was bad.

 

[Thunder]

2Quik6- Well, the PCV is correct, and I don't think it is the cause of the problem. I have gone through, and pinched off different vac lines, to see if there was any change, and no change on the PCV line. Good idea though, and I do have a spare of those as well, and will change it just for the heck of it!! I'll post back if it helps at all.

thanks

 

[Thunder]

ttt

 

[Thunder]

Well, I recorded some direct scan files of the car idling. I did it in 2 psi fp increments, from 42 to 54 line off. I also did it at 45 with the maf plugged in, and 1 at 45 that I disconnected the maf during to compare #'s. The only difference I can see, is that with the maf plugged in, BLM are pegged at 150, INT as well, maf ~4-5, and LV8 in mid, low 30's. After unplugging the maf, BLM come down to 130ish, INT look good, the maf # reads 6 (although it is really unpluged) and LV8 #'s rise to 45 ish. Does this info tell me anything??

thanks

ps If anyone would care to look at the DS files, I can E-mail, or post them.

 

[Roc87]

I talked to Joe Lubrant about a week ago about this problem on mine. For a while I was thinking I had been "taken" with my 50# injectors. I had to turn the Injector constant down in the chip for the BLM's to come off the 160 peg. With the constant at 38# the BLM's are in the 130's. Joe told me to take a closer look at the MAF readings on DS. He says that the lowest the Stock MAF should read at idle is 5. Mine is reading 3. Time to take back that remanufactured POS! I still haven't tried the MAF off of my "donor" for my Iroc swap, but will try tonight. I don't know if this helps at all since you have a Translator. I too have swapped out my 02 more times than I care to remember, many people told me to junk the bosch sensor, so I spent the $ for the AC and it read the same way..
Thunder, do your 02 cross counts go up really slow? Mine aren't anywhere near where they are "supposed" to be. I was thinking that might be the problem also.
Who knows!

 

[gofstbuick]

Even though you checked the egr gasket, is the EGR diaphram ruptured? Try spraying propane under the egr diaphram.

 

[Thunder]

roc87- Well, I currently have my stock maf on the car... (orig I think). I do also have a maf x-xlator, and 3" LT1 maf, but I show zero improvement with that on. Maybe I will throw the x-lator back in, and mess with the base settings till it reads over 5 all the time at idle. (I had only tried it on the standard 3" setting before) Possibly Joes chips do need a higher maf reading at idle, as my stock unit spends most of the time ~4.

gofstbuick- I went through the car looking for vac leaks with the starting fluid, carb cleaner, and stethescope with hose... Although it is possible that I have missed it. I will give it a quick test with the mity-vac, and see if it still holds the vac properly.

thanks for the tips guys!!!

 

[gofstbuick]

If you pump the egr up with a vacuum pump, it probably won't hold, because it's a back pressure type egr valve. But under the diaphram may not seat properly or is defective. That is why you should use propane and blow it right underneath the EGR valve.

 

[Thunder]

gofstbuick- Could you explain how that egr/back pressure system works?? I'm not familiar with this. I did just check to see that is holds vac, and it held 25# vac without dropping at all... I will stop at the hardware store tomorrow, and pick up some propane, and a hose for it to check with.

thanks

As a side note, I changed the settings on my translator, to 3.5" +10% rich, and the BLM dropped into the ~138 range. I put it into gear, and the BLM dropped down ~122. The o2 cross counts seem good. The maf reads 5-6, and LV8 is ~40. It seems to run ok here, although thats just in the garage!! I feel that this may only be a bandaid though, as I really have the 3" LT1 maf, and think I may only be fooling the system.

I'll post more findings later

Thanks to all!!

 

[gofstbuick]

The EGR is a controlled leak between the exhaust system and the intake system. It takes a spent amount of the exhaust gasses and passes it through the intake charge. Thereby cooling the combustion process, in an effort to reduce Nox emissions. The inert exhaust gasses actually take up space in the cylinder, normally occupied by fuel and O2. If the mixture can only fire whats in the combustion chamber, then the mixture can only heat to a certain temperature. The EGR system tries to keep peak combustion temperature below 2500*F. As a by product, the EGR system also limits preignition and detonation. Vehicles equipped with an EGR system can typically run leaner mixtures without fear of detonation.
If the exhaust passages are plugged, then the propane will not matter, the same goes for the intake passages. You should be able to manually lift the EGR diaphram (while the engine is idling) and the engine should stumble. If not, then the passages are plugged and the propane test will not matter. But if the engine stumbles, then you should be concerned about proper EGR operation. The computer will limit EGR operation to cruise while in closed loop. It will not operate in open loop, at idle and during WOT. If the diaphram is ruptured, then when you blow propane underneath the EGR valve, the engine will stumble and the BLM will start to decrease. If the diaphram is not ruptured, then when you blow propane underneath the EGR valve, nothing will change.
Hope this helps, so before you go out and buy propane, check to see if the passages are plugged.

 

[Thunder]

gofstbuick- Thanks for the detailed explanation!! The passages appear to be ok, as the car will stumble at idle with the EGR diaphram lifted. So I will hit the hardware store tomorrow, and see where that propane takes me.

thanks

 

[CaPPY]

Maybe I missed it, but if you are running without a Cat you'll have problems. If you don't have one on, put a good one on and your emissions will drastically change.

 

[2QUIK6]

Originally posted by CaPPY
Maybe I missed it, but if you are running without a Cat you'll have problems. If you don't have one on, put a good one on and your emissions will drastically change.

The cat will not effect the BLMs.
But while on the subject of having no cat, mine will pass the sniffer test here without a cat with the 40# inj. I have. If the car is tuned right and the chip programmed right, and all else is working properly, you should be able to pass emmissions, that is unless the person doing the testing looks to see that you have a cat Most are lazy around here and if it passes the sniffer they don't bother to look.

 

[Roc87]

I think I found my problem!

Thunder, the MAF should never drop below 5 at idle. The lowest it'll go, with out the engine running is 3. Even if it's showing 4, that's a 20% difference than 5. I hooked up my "donor's" MAF to the Buick last night, hooked up DS, fired up the car and watched my BLM's go from 138 down to mid 90's! With that MAF it pretty much stayed around 6, occassionally it dropped to 5, idles alot better (well, it did until the blm's went under 100!) Didn't get a chance to put my chip back where it was (with the 50# injector constant) because of my Home computer being in the shop! I'm assuming when I get the chip back where it was (Before the MAF went south) everything should be close. HTH

 

[TurboDave]

Originally posted by 2QUIK6

The cat will not effect the BLMs.
But while on the subject of having no cat, mine will pass the sniffer test here without a cat with the 40# inj. I have. If the car is tuned right and the chip programmed right, and all else is working properly, you should be able to pass emmissions, that is unless the person doing the testing looks to see that you have a cat Most are lazy around here and if it passes the sniffer they don't bother to look.

While that may be true in TX, there are several states where you cannot pass the sniffer portion without a cat. Irregardless of the proper state of tune. The HC limits in some states (CA, AZ, IL, etc) are low enough that the cat better be there and functioning properly!!!

 

[tcgn]

You are right on TurboDave.I`m a smog tech and without the cat it smells really bad just like the old cars without the cat.Only the
experience can sniff it out.I have seen many cars with the cat on
but smells bad and failed smog test.After replacing the cat,the cat
is usually punched out for performance.