[crazyjag]

Have a slightly modded 90 LX 5.0 (130K miles) with the following:

24lb FRPP injectors
Mac Cold Air induction
Mac Shorty headers
Mac Off Road exhaust
Flowmaster 2 chamber
70 MM TB
73 MM Vortech MAF calibrated to 24lb inj
Complete tune up (Plugs/wires/Cap/coil)
Timing set @ 12 degrees advanced
Adjustable Fuel pressure regulator
155 lph BBK in tank fuel pump

When I drive normally, it sounds like the valves are rattling, but when I get on it, it sounds fine. I always run 93 octane gas in the car, except this time I have added octane boost. I am not getting any codes saying a lean mixture or a O2 sensor issue, the only codes I have are the 44 and 94 for the smog system and water temperture is fine. I have the TP sensor set @ .986 volts. Does anyone have an idea what the problem may be or could it be just the sound of the combination of mods I have on it. What about valve lash adjustment? Don't remember if it required on 5.0's. Thanks....

[BIG G]

make shure you have a factory ect sensor ,not a p.o.s. black plastic one, hot idle ect should be around .58-.90v , maf sensor? are you running a k&n? try cleaning the maf , engine off spraying the sensor inside the tube small wires with crc electrical contact cleaner, spark knock? ping , unplug spout timing connector , if noise still present or better, try what i sugested, let me know.big G

[crazyjag]

Originally Posted by BIGG

make shure you have a factory ect sensor ,not a p.o.s. black plastic one, hot idle ect should be around .58-.90v , maf sensor? are you running a k&n? try cleaning the maf , engine off spraying the sensor inside the tube small wires with crc electrical contact cleaner, spark knock? ping , unplug spout timing connector , if noise still present or better, try what i sugested, let me know.big G

BIGG

ECT was factory, took it out and sanded the brass sensor portion free of tarnish. I also pulled the O2 sensors out and blasted the ends with a propane torch to clean them out. the MASS Air is all brand new, K&N filter is clean. I disconnected the battery for over an hour, then took it for a drive, only to notice the throttle response was better, but still have some of the noise. Ran the codes again and only have the 44 and 94. the only thing I can think of is that since I have a more free-flowing exhaust, it could just be sound generated from the exhaust coming out the stock heads. I guess I will have to just live with it until I do the H/C/I switch. Thanks for the info...