2002
Chevy Express
2500 series
350 engine
AC
229,262 miles


It wants to hesitate when you step on the gas. Sort of sounds as though it is bogging down. As a matter of fact it does sort of slow down when you mash the gas. Now, if I press say 2/3 way down its ok, but when you go beyond that is when it bogs down. It has 229,262 miles. The check engine light was on with a code of random misfire (According to Advance Auto and their tester) They sold me some new plugs and wires which I had put in by a mechanic. The mechanic connected his code thing to the truck and still came up with the random misfire code. The mechanic said it was probably the coil. he said there was only 1 on my van. The check engine light is now off but its still sluggish at full throttle. I changed the oil and filter, PCV valve, the air filter, and the fuel filter. It has a new fuel pump and wire harness as the old one went bad about 1 year ago. Oh yes, and my cousin who is a mechanic suggested to disconnect the part of the air filter where the mass air sensor is located. When I done this the van would barely move. I re connected the mass air sensor and it ran good for a bit, but went right back to being sluggish.

 

Could in fact be your MAF sensor!

 

Is the MAF sensor the mass air sensor? I am lost after the 70's!
Is there a way to test this so I can be sure thats what it is?

 

Yes it is a Mass air flow sensor. (MAF) With GM Delco MAF sensors, attach a digital voltmeter to the appropriate MAF sensor output terminal. With the engine idling, the sensor should output a steady 2.5 volts. Tap lightly on the sensor and note the meter reading. A good sensor should show no change. If the meter reading jumps and/or the engine momentarily misfires, the sensor is bad and needs to be replaced.

 

I shall try this. And thanks for the quick reply. Will post tomorrow as to the findings.

 

Sounds good!

 

Hello wer you able to fix the problem? im having the same problem but mine sounds like a tractor. also same code Random Misfire.