1992 c1500 305 sluggish down low
11-09-2018, 10:21 PM
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1992 c1500 305 sluggish down low
Serious answers or thoughts only please!!!
my 1992 305 tbi feels like it's running out of fuel down low in Rpm's, 1st gear is fine then in 2nd it'll slug until about 50mph and pick up power really hard and does the same through 3rd and 4th, also something to mention that might be important is as soon as it shift it shoots a huge black cloud out of the exhaust but I already know my valve stem seals are SHOT!!! Please help me out anyway you can
my 1992 305 tbi feels like it's running out of fuel down low in Rpm's, 1st gear is fine then in 2nd it'll slug until about 50mph and pick up power really hard and does the same through 3rd and 4th, also something to mention that might be important is as soon as it shift it shoots a huge black cloud out of the exhaust but I already know my valve stem seals are SHOT!!! Please help me out anyway you can
11-09-2018, 11:31 PM
#2
Re: 1992 c1500 305 sluggish down low
Connect a scan tool, look at the data stream while someone else drives the vehicle. Connect a fuel pressure gauge, look at fuel pressure as they're driving and the vehicle is acting-up. Perform a cranking compression test. Buy a spark tester for HEI ignitions--or an adjustable spark tester--and verify that the ignition coil isn't weak.
I'd want to know O2 voltage and cross-counts, short- and long-term fuel trim, coolant temperature, knock sensor activity, and anything else that looks suspicious.
Is there anything left of the catalytic converter? Original? Gutted/removed?
If the valve stem seals are that bad, the plugs might be fouled and the chambers filled with deposits. Oil in the air/fuel mix lowers the octane rating of the fuel, and the deposits can raise compression. Both lead to detonation, detonation leads to knock sensor going crazy, and that leads to retarded timing and poor power. Look at the plugs when you have them out to perform the cranking compression test.
I'd want to know O2 voltage and cross-counts, short- and long-term fuel trim, coolant temperature, knock sensor activity, and anything else that looks suspicious.
Is there anything left of the catalytic converter? Original? Gutted/removed?
If the valve stem seals are that bad, the plugs might be fouled and the chambers filled with deposits. Oil in the air/fuel mix lowers the octane rating of the fuel, and the deposits can raise compression. Both lead to detonation, detonation leads to knock sensor going crazy, and that leads to retarded timing and poor power. Look at the plugs when you have them out to perform the cranking compression test.
11-10-2018, 01:53 AM
#3
Re: 1992 c1500 305 sluggish down low
Good to see you Shurkey...used to see you all the time on W-body.com.
I was thinking if he’s got an oil control problem, the O2 sensor is probably already hosed...but the sensor info you asked for would tell the tale.
I was thinking if he’s got an oil control problem, the O2 sensor is probably already hosed...but the sensor info you asked for would tell the tale.
11-10-2018, 02:53 AM
#4
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Re: 1992 c1500 305 sluggish down low
Its a truck, and the only place to plug in for checking pressure on a TBI is under the drivers seat along the frame with an adapter between the tank and the fuel filter, so lol please dont drive down the road, door open looking down at the pressure.
11-10-2018, 11:15 AM
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Car: 1991 S10 v8 AWD
Engine: 5.7 TBI
Transmission: 700r4 with vette servo upgrade
Axle/Gears: 3.73
Re: 1992 c1500 305 sluggish down low
I use This adapter , and plug it directly behind truck tbi, and just put gauge under windshield wiper to hold it down.
11-10-2018, 04:55 PM
#6
Re: 1992 c1500 305 sluggish down low
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