We've been having a problem with my son's 1988 Chevy K2500 4x4 w/ 350 for the past couple of weeks.
The idle speed is low- 500rpm or so, and erratic, it hesitates when you get on the gas, sometimes stalls after reving and almost stalls when put in gear. This often happens when the truck is cold though it's worse when it's warmed up.
So far we have-
-Checked and set the timing
-Replaced the EGR valve- the old one failed a vacuum test
-Tested the EGR solenoid- it appears to be fine
-Checked for vacuum leaks and found none
-Tested the IAC- it moves and the resistance on my DMM is correct
-Tested the TPS- it appears to be fine
-Tested the CTS- it appears to be fine
-Tested the MAP- it appears to be fine
-Fuel pressure is good
-Fuel flow is good and the filter is recent
-The spark plugs are all tan and in good shape
I'm a little wary of the new EGR valve. It's a Duralast and I've read that we should've stuck with an OEM unit.
The iginition module was replaced recently due to another issue.
We replaced the engine in this truck with a rebuilt short block about 8,000 miles ago and it has run well until recently.
Thanks in advance!
The idle speed is low- 500rpm or so, and erratic, it hesitates when you get on the gas, sometimes stalls after reving and almost stalls when put in gear. This often happens when the truck is cold though it's worse when it's warmed up.
So far we have-
-Checked and set the timing
-Replaced the EGR valve- the old one failed a vacuum test
-Tested the EGR solenoid- it appears to be fine
-Checked for vacuum leaks and found none
-Tested the IAC- it moves and the resistance on my DMM is correct
-Tested the TPS- it appears to be fine
-Tested the CTS- it appears to be fine
-Tested the MAP- it appears to be fine
-Fuel pressure is good
-Fuel flow is good and the filter is recent
-The spark plugs are all tan and in good shape
I'm a little wary of the new EGR valve. It's a Duralast and I've read that we should've stuck with an OEM unit.
The iginition module was replaced recently due to another issue.
We replaced the engine in this truck with a rebuilt short block about 8,000 miles ago and it has run well until recently.
Thanks in advance!