5.3 swap wont run correctly - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Caleb · 07-22-2015, 03:17 AM

my 5.3 out of an 02' 1500 will start and idle around 400 RPM for about 30 seconds before it dies. i have no clue what is wrong. took it to 2 shops both dont know whats wrong and they refused to work on it said it wasnt worth their time. so instead of wasting time with other people im gonna finish this thing myslef. i have 51PSI fuel pressure. got new intake gasket because it failed my smoke test. i thought it may be a bad MAF sensor. it backfires through intake a little and the plugs look fouled. got new ones and when i get it back im gonna swap it out. it has a p0030 trouble code. also according to the shops the STFT and the LTFT dont log at all they stay 0%. builder said he gonna reflash a new PCM and send it to me to rule that out. i could use some serious help. thank you.

chuckmc8 · 07-24-2015, 06:44 AM

One possibility is that the oxygen sensor wires may be connected to the wrong side of the engine. The longer it runs the worse it gets--

White knuckle Garage · 07-31-2015, 02:35 PM

Potential causes of a P0030 trouble code may include:
•Failed or damaged heater circuit element inside the HO2S
•Open on the O2 sensor heater's ground circuit
•Open or short on O2 sensor heater's B+ battery feed (on some vehicles this may be the control circuit)
•Possible ECM failure (less likely)

Possible Solutions

Many times a HO2 sensors heater element may go bad due to age or impact. Keep this in mind when making your inspection. Make a visual inspection of the Bank 1,1 O2 sensor. Repair any damaged wiring from contact with exhaust.

If HO2 Sensor itself appears to have been damaged, replace it. If a visual inspection reveals no obvious problems, viewing the faulty heater circuit on a scan tool may reveal if the fault is currently occurring. If the scan tool datastream shows that the Bank 1,1 heater element is pulling 0 amps then suspect an open in the circuit. Check for blown fuses and then disconnect the O2 sensor connector.

With key on engine off use a voltmeter to check for 12 volts fused battery feed to the heater element. If there is no voltage present, repair open or short in the B+ feed circuit remembering to replace any fuse blown from the short. If the B+ battery feed is intact, remove the ground (control) circuit from the ECM wiring connector and check for resistance on the circuit. If there is infinite resistance, repair open in the circuit. If the control circuit checks out, suspect a bad O2 sensor. Replace and re-check.

07-22-2015, 03:17 AM	#1
Caleb Registered User Join Date: Jul 2014 Location: Castle Rock, Colorado Posts: 49	5.3 swap wont run correctly my 5.3 out of an 02' 1500 will start and idle around 400 RPM for about 30 seconds before it dies. i have no clue what is wrong. took it to 2 shops both dont know whats wrong and they refused to work on it said it wasnt worth their time. so instead of wasting time with other people im gonna finish this thing myslef. i have 51PSI fuel pressure. got new intake gasket because it failed my smoke test. i thought it may be a bad MAF sensor. it backfires through intake a little and the plugs look fouled. got new ones and when i get it back im gonna swap it out. it has a p0030 trouble code. also according to the shops the STFT and the LTFT dont log at all they stay 0%. builder said he gonna reflash a new PCM and send it to me to rule that out. i could use some serious help. thank you. __________________ 1986 K1500 Pro-Street 4x4

07-24-2015, 06:44 AM	#2
chuckmc8 It's alsways something..... Join Date: Nov 2008 Location: Douglasville GA Posts: 1,171	Re: 5.3 swap wont run correctly One possibility is that the oxygen sensor wires may be connected to the wrong side of the engine. The longer it runs the worse it gets-- __________________ 1968 RS Camaro 'Vert Matching number 327 and M21 Muncie 1968 C10 Black with red interior and orig paint. 5.3 / 4l60e,3:73 POSI 17" Torq Thrusts 1968 CST 514 Red with black interior. Buddy Buckets, Factory A/C, PS, PB- 20" AR custom shop TT, 5.3 and 4l60e

07-31-2015, 02:35 PM	#3
White knuckle Garage Registered User Join Date: Dec 2014 Location: Ada Oklahoma Posts: 112	Re: 5.3 swap wont run correctly Potential causes of a P0030 trouble code may include: •Failed or damaged heater circuit element inside the HO2S •Open on the O2 sensor heater's ground circuit •Open or short on O2 sensor heater's B+ battery feed (on some vehicles this may be the control circuit) •Possible ECM failure (less likely) Possible Solutions Many times a HO2 sensors heater element may go bad due to age or impact. Keep this in mind when making your inspection. Make a visual inspection of the Bank 1,1 O2 sensor. Repair any damaged wiring from contact with exhaust. If HO2 Sensor itself appears to have been damaged, replace it. If a visual inspection reveals no obvious problems, viewing the faulty heater circuit on a scan tool may reveal if the fault is currently occurring. If the scan tool datastream shows that the Bank 1,1 heater element is pulling 0 amps then suspect an open in the circuit. Check for blown fuses and then disconnect the O2 sensor connector. With key on engine off use a voltmeter to check for 12 volts fused battery feed to the heater element. If there is no voltage present, repair open or short in the B+ feed circuit remembering to replace any fuse blown from the short. If the B+ battery feed is intact, remove the ground (control) circuit from the ECM wiring connector and check for resistance on the circuit. If there is infinite resistance, repair open in the circuit. If the control circuit checks out, suspect a bad O2 sensor. Replace and re-check.



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