01 5.7 Vortec, Missing/hestitating

yukon25008.1 · May 28, 2010

i have an 01 chevyexpress cargo 2500 5.7. just started missing. confused because everything is new

plugs&wires

cap&rotor

pcv

fuel filter

seafoam treament

cleaned intake&maf

it does need front 02 sensors replaced.. would spraying the old ones with throttle cleaner cause a problem? it seemed to run better the day after i cleaned them..

wierdo124 · May 30, 2010

Probably a bad injector. is it missing on the same cylinder?

Arlen · May 30, 2010

i have an 01 chevyexpress cargo 2500 5.7. just started missing. confused because everything is new

plugs&wires

cap&rotor

pcv

fuel filter

seafoam treament

cleaned intake&maf

it does need front 02 sensors replaced.. would spraying the old ones with throttle cleaner cause a problem? it seemed to run better the day after i cleaned them..

Hi I have a similar van A 2001 Savana 3500 with 5.7 vortex engine. how is your van holding up? How many miles:?

yukon25008.1 · May 30, 2010

How do i test/check to see if its a bad injector?

i thought about replacingthe coil pack with a msd replacement

yukon25008.1 · June 1, 2010

would i have hurt the o2 sensors trying to clean them?

yukon25008.1 · June 5, 2010

just replaced the fuel pump.. still have to hold the key on for the pump to cycle so it will start.. and the miss seems less but its still there at different times. not so much under a load. more at low rpm,s

yukon25008.1 · June 6, 2010

is there a fuel pressure regulator on this model somewhere at the engine that could be the problem,

yukon25008.1 · June 11, 2010

?????

yukon25008.1 · July 13, 2010

matsrat · July 15, 2010

fuel pressure is located in the intake manifold along with the injectors. do a compression check, all cylinders should be within 10% of each other. should be 130psi-150psi. if lower,like 90psi there is internal problems, valves or rings.

yukon25008.1 · July 15, 2010

since my last post i changed the fuel pump, runs slighty better, but still have to hold the key for 5 secs before trying to start, and the miss isnt real bad its just there in an out, seems at lower rpms

steiny93 · July 21, 2010

Used to have a 1998 5.7; one of the injectors stuck and it missed / hesitated real bad. My understanding is that there is a valve in each injector that sticks, an engine clean can solved the issue.

But it threw a code right away, are you seeing a code?

czycoot1318 · July 21, 2010

Had the same problem at low RPM's and sometimes when taking off, just a slight miss or hesitation. Threw a code saying it was the MAF sensor so I cleaned it out. It helped a little bit but it would still intermittently miss. Decided to just change out the MAF for $130 from Advance Auto. Fixed the problem and now she runs great.