Running rich
 

Put the EEHACK on the ALDL to record real time and noticed the O2 sensors mlv went from about 57 to over 750. The readings ran u and down like crazy. Any idea what would cause this?

10-1000 millivolt moving up an down is what it does.

Still trying to find out why the engine is running so rich. BLM steady at 128 and good fuel pressure. To say it's running rich is an understatement. When I start it the exhaust blows black soot on the floor. This is an unknow engine. It appears to have been overhauled because the innards are as clean as new. Does not burn oil (rear main leaks a bit). Tried to get the number off the fuel injectors but it looks as if they were cleaned to the point of wiping off any numbers. What else could cause a super rich condition?

coolant temp switch/sensor going bad. they can read -40 degrees which causes major rich condition. I think we went through that aready though. I currently have 30lb injectors in mine but it's built pretty good. 26lb I believe is stock if memory serves. I took my racks off with injectors still on them and set cardboard squares under each injector and cycled the pump, turned key on and off, to see if they was bleeding or stuck open. I found my fuel pressure was too high for those injectors, once I got pressure down they worked but still rich, sent them into injector shop to be tested. all but two was shot. he sent me flow tested set that have worked for a long time.

Craby, can you remember if the 30# injectors have the same profile (look-alike) as the stock 26#? As this is an unknown engine that appeared to have been overhauled I have questions regarding some of the parts. Not sure but maybe a non-stock cam which could also lead to larger injectors. As mentioned the injectors were cleaned to the point they no longer have numbers on them. Dumb me, haven't done the simple test of using brake cleaner to check for vacuum leaks. Do the basics before throwing parts at it.

Well I found an INDICATION of the problem. Ran EEHACK and watched the BLM numbers. In closed loop the left bank read 141 and right was a bit lower at 137. Think they should read 128. Question is: What is causing this? Is it the program or is it larger injectors? How can I track down the cause and correct it? Any ideas?

Couldn't stand not knowing what I have for injectors. Pulled the fuel rail and was able to see the numbers with a magnifying glass. That leaves only two things to cause it to run rich: program or leaks. Can't find any vacuum leaks so I dug out a second ECU that was programmed for a turbo 350 and sent it off to get it tuned for the 4L60E. Time will tell if that's the problem.

yes they do look the same so long as they are the same brand and style. metal ones are way different looking then plastic ones.

Got a new tune in the PCM and running much better but still a tad rich according to the tuner. Really nice day today so I put the top down on the roadster and ran errands and just wheeled around town. Parked the roadster in the street while I cleaned the garage floor then pull the roadster into the driveway and smelled gas. Noticed a big wet spot in the road and a line running onto the driveway. Quick look under the hood and gas dropping everywhere. Let it cool down and dry up then started it again. Gas spraying like a Rainbird from the front fuel rail crossover. Took the fuel rail off and unbolted the crossover. One of the O-rings was split in half! Picked a nice place to fail if I must say so. Of course no OEM O-rings at any parts store so I matched them as best I could, installed them and NO LEAKS. Bet I'm the only one west of the Mississippi that has had that type of O-ring failure.

Was able to download the zip file from the tuner, unzip it and used Flashhack to reprogram. Much better! Will do a data log later today when the weather warms a up a bit. At the very least I highly recommend using EEHACK on your 94-95 OBD1 cars. It will tell you lots of good info. Only drawback is the cost of a Moats cable. Everything else is free. The other two free programs are FLASHHACK and TUNERPRO.