5.0 backfires - problem solved!

[SC74]

The 5.0 in my crawler started backfiring, running rough, and very little power the other day after I pulled it out of the garage after working on the rear suspension. I couldn't get it to idle up without it either backfiring or stalling out. When I first cranked it cold it was fine - even power braked it (not enough to spin the tires but enough to put a load on it).

I let it cool and it cranked and ran fine again.

Cranked it again tonight after work and it's still good.

I did leave the battery off of it for a couple weeks while I was welding on it and I know the computer has a learning curve, but I am starting to think this is more heat related.

Where do I start looking? It has not thrown any codes. I could not tell you my timing and have no reference with the explorer serp on it. We timed it by ear when we first started it and I haven't had issues with it before.

[blazinchuck]

double check every single plug and connector...make sure the computer is connected. good ground?

can you post a video of it running? i weld all the time on my rig with everything still connected and plugged in. do you have a check engine light hooked up?

[SC74]

I will double ck all of my electrical connections.

My grounds should be good - I've been down that road with this motor already but it still wouldn't hurt to add another ground or two to be safe.

I will see if I can do a vid. Yes, the ck engine light is working. It lights up when the key is turned and cuts off when it starts.

[broncosbybart]

where is your engine temp sensor located? is it full of water? any sensors that aren't hooked up?

it would be a good idea to check timing. the stock explorer balancer does have timing marks on it. i timed mine without issue.

mine started acting up when it gets warm as well. hadn't checked into why yet.

[chuzie]

Are you running KOEO and KOER codes?

Is this an exhaust or intake backfire?

Timing or vac would be my first stop after a KOER test.

[bucketobolts]

I'd check the coil and ignition since it seems to be heat sensitive.

[chuzie]

I agree with bucket. The coil is a classic offender when it comes to heat sensitive issues.

[SC74]

where is your engine temp sensor located? is it full of water? any sensors that aren't hooked up?

it would be a good idea to check timing. the stock explorer balancer does have timing marks on it. i timed mine without issue.

mine started acting up when it gets warm as well. hadn't checked into why yet.

Can't remember about the location of temp sensor and will look tonight. All sensors are hooked up to best of my knowledge.

Timing is going to be my first place to go.

[SC74]

Are you running KOEO and KOER codes?

Is this an exhaust or intake backfire?

Timing or vac would be my first stop after a KOER test.

Don't know enough about the efi to tell you KOEO or KOER - i'll have to figure that one out cratchhe:

Both intake and exhaust backfiring.

[SC74]

I'd check the coil and ignition since it seems to be heat sensitive.

I will check this also - it was bought "new" from auto zone but it has been sitting for some time now.