Block learn reading. 89 L98
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Joined: Feb 2014
Posts: 88
Likes: 7
It means that the computer is adding fuel to keep the correct air/fuel ratio. Does the car have any mods that would require more fuel than the stock tune?
If the car is stock, and the the BLM is high, the first thing you might want to check is the fuel pressure to see if it is low. If it is low, that would make the BLMs increase. How old are the oxygen sensors? How fast are the O2 cross counts increasing?
Data log the car some more and see if the BLM is high across all RPMs, or if it is high at just certain RPMs.
If the car is stock, and the the BLM is high, the first thing you might want to check is the fuel pressure to see if it is low. If it is low, that would make the BLMs increase. How old are the oxygen sensors? How fast are the O2 cross counts increasing?
Data log the car some more and see if the BLM is high across all RPMs, or if it is high at just certain RPMs.
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,504
Likes: 73
From: Georgetown TX
The car is mostly stock. Had injectors replaced with Bosch 3 a couple years ago. Only have about 2000 miles totL since then. Took screen off of MAF. 180 degree thermostat. All smog stuff still there. I did replace fuel pump recently and I noticed pressure just a taste lower at idle then old one. Noticed the filter stock was smaller and flatter the oem Car only had 49000 miles. Did vacuum test with gage and sprayed starter fluid the only thing I noticed was that I would get a very small tick on the vacuum gage which would correspond with an idle miss I am trying to locate. I have had the miss since I got it. Reading up, I found that that COULD be among other things, an electrical problem. I have replaced wires plugs cap roter and will be replacing spark control inside of distributer. Also have new O2 sensor coming. I noticed car wants to stay in open loop moe then I think it should. Keep in mind I an new to this and may not know what I am taking about
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,504
Likes: 73
From: Georgetown TX
Had corvette shop replace injectors. I think they equaled stock size. I had miss fire before replacement. Only notice it at idle. Car does not miss under load. This coming week I am going to unplug one at a time, the plug wires at the distributer to locate miss fire
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You might have spark leakage. Look for arcs at night in a dark garage with the engine running.
You might want to pull out all the spark plugs and look for one (or more) that looks different from the others. Usually it's pretty obvious is one plug is not firing (it will be wet with fuel as opposed to dry).
