48 chevy truck

[kb426]

Minor work today. I set the tail pipe height with the truck in the air. When it was on the ground, the pipes were 2" lower than I wanted. That got remedied today. Lower a arms were what I used for height the 1st time. Sheesh, where's the brain power?

[kb426]

O&S earned the title today. I was going to remove the alum oil pan and install a steel one left over from the 32. Should be 2 hours worse case. Many hours later, the front crossmember has been trimmed in stages. I'd cut some and trial fit. Cut some more and repeat. When I removed the alum pan, I looked as best as I could and I don't think the front seal was leaking, not positive about the rear. After installing the steel pan and letting it run for a while, I changed oil and went for a short drive. I'm cautiously optimistic one more time.

[kb426]

Yesterday, I pulled the plenum of the intake and vacuum tasted everything I could. I found nothing. I glued everything back together including the throttle body. It still has the intermittent miss. However, the oil pan is dry. I put about 30 miles on it today ranging from 60 to 80 and there is no regularity to the miss. I have used my Torque program and all of the numbers it puts up are within the Ford obd2 manual that I found. I have wiggled wires, rechecked connections and most items twice. I also think it's weak on power in 5th gear. I'm wondering if the explorer tune was soft because of emissions or fuel mileage. I'm about to make a decision as to pursue or change efi systems.

[jaybee]

You may be onto something with this latest thought. Does the truck have a wideband O2 sensor you can read? If you have less restrictive intake and exhaust, that may be enough to mess with your tune. A little Google work on what mods required a tune on Mustangs of the vintage you got your engine out of would probably give you some idea.

[idrivejunk]

Sounds like a job for HPtuner (alterations via tune ["canned"?]), rather than just monitoring with Torque and comparing to stock parameters. Because the engine is in a different package, powering a different weight, gears, way way more drag, altered exhaust, etc. Just an engine-dumb bodyman observation.

[kb426]

Jaybee, no wideband, Matt, not a bad idea but I still think there is something malfunctioning on the system. I just pulled plugs and checked the spark plug wires for resistance. I didn't find anything, once again. It's not in my behavior to give up but I have about extinguished my thought processes for this.

[idrivejunk]

If you ain't already, put some extra sweet gas in it, see how she runs? Are you getting a normal amount of knock retard? That 02 sensor stuff is yep a sticky wicket, don't they need a certain temp range to function proper? You're getting open loop, right?

Just tossing out a clueless batch of variables which might intertwine with ambient conditions. It might stumble if the computer encounters lugging in high humidity, etc? Is the computer for stick or auto? Is ot learning? Crank trigger relearn?

Blah blah... shots in the dark with all I got. If good will vibes from peers are worth anything a solution will boil out soon. 

[kb426]

I have made some small changes to the wiring harness. I wondered if my splices on the power feed to the efi relays were 100%. I removed the splices and put ring terminals on all of the wires and they are connected with a bolt and nylock nut. Then I covered it with shrink wrap. I went for a 60 mile cruise this afternoon. When pushing the wind, (25mph) it hiccuped a few times. With the tail wind, there were no hiccups. I don't have any conclusions at this point so I'm just going to drive it. When I pulled the plugs last week, it looked as normal as I've seen. I have 120 miles on it since the oil pan change and it's clean and dry. I think the seat may be the next task. ?
Matt, I tend to think I have an electrical problem rather than efi. But I'm not sure about anything. As I have said in the past, several times I have said " what did I do".