low idle

[vortec345]

hello ,

 

i have a 92 s15 jimmy 4.3l vin w ( cpi ) - and it seems that the idle is too low and some times shakes - replaced cap/ rotor / tune up / tps / 02/ wires - shows up in closed loop only - fuel pressure is 54 engine running -when i crack the throttle it goes up to 62 .

 

 

any help appreciated

[Big Jay]

hello ,

 

i have a 92 s15 jimmy 4.3l vin w ( cpi ) - and it seems that the idle is too low and some times shakes - replaced cap/ rotor / tune up / tps / 02/ wires - shows up in closed loop only - fuel pressure is 54 engine running -when i crack the throttle it goes up to 62 .

 

 

                            any help appreciated

 

<{POST_SNAPBACK}>

 

 

check compression,do leak down test.may have bent valve/ bad cylinder.while truck is running take the plug wires off the spark plug the engine will miss if cylinder is firing reinstall cap do all cylinders one by one .If you find no change on one or more cylinder time to pull the head and see whats up.

[JOE2003]

hello ,

 

i have a 92 s15 jimmy 4.3l vin w ( cpi ) - and it seems that the idle is too low and some times shakes - replaced cap/ rotor / tune up / tps / 02/ wires - shows up in closed loop only - fuel pressure is 54 engine running -when i crack the throttle it goes up to 62 .

 

 

                            any help appreciated

 

<{POST_SNAPBACK}>

 

 

check compression,do leak down test.may have bent valve/ bad cylinder.while truck is running take the plug wires off the spark plug the engine will miss if cylinder is firing reinstall cap do all cylinders one by one .If you find no change on one or more cylinder time to pull the head and see whats up.

 

<{POST_SNAPBACK}>

 

 

 

[JOE2003]

hello ,

 

i have a 92 s15 jimmy 4.3l vin w ( cpi ) - and it seems that the idle is too low and some times shakes - replaced cap/ rotor / tune up / tps / 02/ wires - shows up in closed loop only - fuel pressure is 54 engine running -when i crack the throttle it goes up to 62 .

 

 

                            any help appreciated

 

<{POST_SNAPBACK}>

 

 

check compression,do leak down test.may have bent valve/ bad cylinder.while truck is running take the plug wires off the spark plug the engine will miss if cylinder is firing reinstall cap do all cylinders one by one .If you find no change on one or more cylinder time to pull the head and see whats up.

 

<{POST_SNAPBACK}>

 

 

 

check the idle air control vavle they intend to clog up with carbon check for vacume leak back by the dis cap their is a hose that is sometimes knock off when replacing the cap check it out

[Cranky1]

hello ,

 

i have a 92 s15 jimmy 4.3l vin w ( cpi ) - and it seems that the idle is too low and some times shakes - replaced cap/ rotor / tune up / tps / 02/ wires - shows up in closed loop only - fuel pressure is 54 engine running -when i crack the throttle it goes up to 62 .

 

 

                            any help appreciated

 

<{POST_SNAPBACK}>

 

 

 

 

Most 4.3 engines idle poorly. In the fall and early spring, our Jimmy will flash the code for engine knock sensor. It is not the sensor, the knock sensor will retard or advance the timming to smooth out the ruff idle, when it goes out of range I get the service engine soon light with that code.

 

Every spring and fall I clean the throttle body and drive it like I stole it afterwards. I have taken out the EGR valve a few times over the years and cleaned it because pieces of carbon will get stuck there, it will idle poorly and engine vacuum will become low and I loose brake boost.