5.7 runs bad when warm sometimes
Asked by GuruCJ5L Oct 17, 2017 at 12:41 PM about the 1997 Chevrolet C/K 1500 Silverado Extended Cab 4WD
Question type: Maintenance & Repair
I have a 97 K 1500 with intermittent running problems when
warm it doesn't always do it had just started it recently
after changing the rear end which shouldn't have anything
to do with it I noticed it mainly when using cruise control
cuz it's at very low RPM just like cruising down the highway
it feels like somebody turn the ignition off and then on
again just intermittently and it never does it cold thing runs
great other than that you can step on it takes right off no
problem but it doesn't always do it either I can drive it all
day long if I don't shut the truck off it never gives me any
issue some days It fired up you go 3 miles and it starts
acting up anybody have any ideas on this the only codes it's
throwing is mass air flow and also 02 I change the throttle
positioning sensor because it felt like it was at the same
throttle position every time and it's at low RPM 14 1500
RPM
11 Answers
enginecreator answered 6 years ago
Well the thing about its like it shut off and come back on, sounds like a ground issue but the MAF and o2 may be connected to this or another all together issue but they are likely connected to each other.
enginecreator answered 6 years ago
Those sensor codes together usually mean exhaust, intake gasket, vacuum or a gasket leak.
enginecreator answered 6 years ago
O.k. Maf & cam sensor, those 2 are also on the same fuse on a lot of gm trucks. Look at your fuse Panel under dash & may be under hood, I think under dash has Eng. 1 Fuse should be 20 amp. See if it or any others are bad. If not then will have to look farther.
enginecreator answered 6 years ago
If that eng. 1 fuse is blown and it blows the new fuse then need to search all those circuits on that fuse for shorts, one post I found that has these codes and blowing the eng1 fuse a downstream O2 had internal short which was found by using a multi-meter to check with.
Thanks you were right it was a blown fuse truck runs great again can't believe I quit driving it because of something so simple thanks again
enginecreator answered 6 years ago
Good deal, Something may have shorted to burn the fuse, but the circuits on any fuse can be figured out & tested.
I thought about that so I figured I'll drive it for awhile and if it blows again I will dig into it deeper to find the short checked the wiring as far as I could without getting into the harness too much everything look good so I figure I'll just run it for a while if it start screwing up all know where to look that fuse and if so I'll pull the O2 sensor and check it out but until then I think I'm just going to leave it alone the weather where I live right now is pretty nasty it's not like I really want to get underneath of it unless I have to thanks again I appreciate your help
