High BLM while cruising.
#1
Senior Member
Thread Starter
iTrader: (2)
Join Date: Aug 2014
Location: Fort Collins, CO
Posts: 575
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1991 Firebird Formula
Engine: 5.7L TPI
Transmission: 700r4
Axle/Gears: 3.23
High BLM while cruising.
I'm looking for a little help diagnosing why my computer is seeing a very lean condition. While cruising on the highway it is consistently getting up to 160 BLM for extended periods of time. I did not find any vacuum leaks by spraying water; I don't have propane so I can't use that method. The injectors are reman Bosch III's from southbay for a 350. I've ohm checked my injectors, and verified that they are not leaking by clamping the feed and return lines. The fuel pressure according to my harbor freight gauge reads 35 with the vacuum line on and around 42 with it off. Driving, the fuel pressure mostly stays at 35 and did not really ever get over 40 that I noticed.
I've uploaded two TunerPro logs which may be useful. One's from a short drive and the other's from about an hour and a half drive on the highway. http://s000.tinyupload.com/index.php...33554646146233
I've uploaded two TunerPro logs which may be useful. One's from a short drive and the other's from about an hour and a half drive on the highway. http://s000.tinyupload.com/index.php...33554646146233
#2
Senior Member
Thread Starter
iTrader: (2)
Join Date: Aug 2014
Location: Fort Collins, CO
Posts: 575
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1991 Firebird Formula
Engine: 5.7L TPI
Transmission: 700r4
Axle/Gears: 3.23
Re: High BLM while cruising.
So today my car threw a code 32 (egr issue). Pulled over to pull the code and when I tried to start it again I would either run horribly or stall out. I'm thinking it's probably because my egr is sticking open. Got it to run decently by unplugging the vac line to the egr and it eventually went back to normal. I haven't seen if the BLM is any better with the egr disconnected, is it possible that a sticking egr was the cause? I've got a new egr on the way but for now I'm going to just leave the vacuum line unplugged.
#4
Senior Member
Thread Starter
iTrader: (2)
Join Date: Aug 2014
Location: Fort Collins, CO
Posts: 575
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1991 Firebird Formula
Engine: 5.7L TPI
Transmission: 700r4
Axle/Gears: 3.23
Re: High BLM while cruising.
I got the EGR replaced (pretty easy job except that we had rtv'd the darn intake gaskets down; scraping gaskets off of intake runners while they're still on the car is a royal pain.) The BLM has gone back to acceptable levels, usually sitting somewhere between 130 and 150 but not pegging out at 160 anymore. My MPG has also improved a lot. I went from around 14 mpg to 22 this last trip.
#5
Senior Member
Join Date: Apr 2007
Location: wallingford,ct
Posts: 668
Likes: 0
Received 0 Likes
on
0 Posts
Car: 91 formula ws6
Engine: 355 tpi OBDII
Transmission: 4l60E
Axle/Gears: 2.73 with 4th gen brakes
Also verify that 35 psi is correct for those injectors. I know I had to set mine at 43.5 psi to obtain the proper rating. Just a thought
Thread
Thread Starter
Forum
Replies
Last Post