I have a 94 chev 1/2 ton 305 TBI that is failing the emission tests. Any info on the sensors, ohms readings or voltages would be appreciated for the EGR solinoid, the ohms for each injector, and anything else that would cause a VERY rich mixture in the TBI. Knock sensor tests ok along with the EGR valve.........PLEEEEEEEEEESE HELP
Is it only failing hydrocarbons or is it failing NOx and other emissions as well?
Doc
limit reading result HC ppm 73 255 fail CO % 0.41 1.06 fail NO ppm 1160 65 pass
this is all at 1329 rpm simulated highway driving @ 40 KPH. Also the Cat has just been checked and is clear, plugs replaced, wires replaced this spring, and the cap cleaned and the rotor also was cleaned. I hope the readings come out ok in the chart form.
Here are the readings in a better form
item Limit Reading Result HC ppm 73 255 fail CO % 0.41 1.06 fail NO ppm 1160 65 fail
In one chart NOx is pass, the other is fail. Which is it?
With your HC's and CO being all out of whack, it's running sloppy rich and there are very few things that can cause this:
1) Faulty CTS 2) Faulty O2 sensor 3) Ruptured Fuel Pressure Regulator diaphramChecked your ECM for codes yet?
Doc
Sorry the NO is a pass, my error, what and where is the CTS. Before replacing the plugs, I got a 43 which is the knock sensor(which tests good) or the ESM (haven't tested it). What and where is the feul pressure reg. diaphram.
Right now I don't have any codes, but later this morning, I am going to take it for a drive to test for any codes.
Well, took it for a drive and got a 44 code, with everything connected.
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