5.0 backfires - problem solved!

[SC74]

Just on what I have read I would be looking for a ground or power problem. All of those codes are realted to low or incorrect voltage.
I have a bunch of wiring diagrams if you need any, what year is the 5.o from?

Thanks Matt... I am so lost on this efi stuff and don't even know what / where to look. There's only one way to learn though and I'm learning fast.

From reading on classic, the 81, 82, 85, and 84 are all codes that are expected to be thrown during this conversion and nothing to worry about.

The one that does require concern is 22 - BP Sensor. I bought this sensor new, so wouldn't suspect it being bad but it wouldn't be the first part I bought new that was bad either. If the BP casing grounded itself I would run a dedicated ground to it but it's just a plastic housing.

[SC74]

I found that the wire harness plug going into the BP sensor seemed loose. The plastic tab does not hold it tight and you can remove the plug without prying the tab up. Since the plug comes from the bottom side it can easily work its way loose on it's own.

I un-plugged and firmly re-plugged the wires back into the BP sensor and it seems to be running MUCH better. I got it up to 200* and it only backfired twice - both out of the exhaust and no intake backfires. I think that could be a timing backfire since we never technically timed it better than to the ear.

My fuel line never seemed to purge and I cannot connect these two issues and am wondering if it was my imagination.

Next problem - the very back cylinder on the pass side was making the header tube glow red. :banghead:

[chuzie]

Check to make sure you have the same injectors throughout the series. Congrats on the BP sensor. The computer is your friend, if you let it be.

[SC74]

I bought all 8 injectors at one time and put new o-rings on them and did not notice any difference. I have learned to let the computer be my friend for sure!

My headers are the WH ceramic coated - no reason for these to get red the first so many times they get hot is there?

[chuzie]

They are getting red with normal operation? You may have a fuel scheduling issue. How does the exhaust smell? How do the plugs look? KOER test and timing.

[bucketobolts]

Could be a leaky injector or retarded base timing. The only reason the exhaust will heat up enough to glow is because there is fuel burning in the exhaust. What does the plug look like?

[SC74]

Will pull the plug to inspect and let ya'll know.

[SC74]

School me on doing a KOER test. Do I connect the STI before or starting the motor? Any special method of doing things?

[chuzie]

This procedure assumes you have just completed a KOEO test.

KEY ON/ENGINE RUNNING (KOER) SELF-TEST
NOTE: If engine will not start, go to TEST A. If engine starts but
stalls while testing, go to DIAGNOSIS BY SYMPTOM TEST.
Code Output
1) Deactivate SELF-TEST (disconnect jumper wire). Start
engine and run it at 2000 RPM for 2 minutes to warm up HEGO sensor.
Turn engine off and wait 10 seconds
2) Start engine. Insert jumper to activate SELF-TEST. The
engine ID code will be displayed.
3) If a Dynamic Response code occurs, briefly accelerate
engine to wide open throttle (WOT). DO NOT depress throttle during
test unless a Dynamic Response code occurs. The KEY ON/ENGINE RUNNING
(KOER) SELF-TEST service codes will then be displayed. Observe and
record all codes.
NOTE: On the 5.0L SEFI engine a service code 98 may appear instead
of the engine ID code, indicating the need to obtain a code
11 for the KEY ON/ENGINE OFF (KOEO) SELF-TEST portion of the
QUICK TEST.

[Timstrk]

Negative on the "too much gas" theory. Too much Air. Running lean. Heats the headers to cherry red. More gas in the mix and they run cooler.