Before I do the deep dive on the plenum......I am taking it in to see if the brake booster is bad. When I fire the truck up and first drive it there is something that sounds like a vacuum leak.

The thing that has me looking at the brakes is when they pumped up by themselves at low speed and the ABS lights when out.

I'll do a backflip is this is it.

We will see

HK

 

Still need to put good copper plugs in. Autolite 3923 I think is one of the part numbers, NGK BKR6E (6962) are the general preferred though. Gapped at .040 . The magnum heads do not swirl well and do not have a flame front compatible with a platinum or iridium plug.

 

Ok has the brake booster checked at a brake shop...... Brake booster is good. Their scan tools cannot read the ABS modules.....it just generates a fault code.

Next up will be looking at the vacuum pump under the battery tray. I know it has a few cracked lines.

The misfires certainly seem vacuum related.

BTW when I pulled and replaced all the plugs and inspected them.....there was nothing abnormal on the cylinder 3&5 plugs. They looked the same as the rest.

HK

 

If no physical signs of rich/lean/misfire, then I'm definitely looking at the oxygen sensors. The change of vacuum might skew the sensors just enough to trip the threshold.

 

Start from scratch with ALL oem Mopar sensors NGK basic plugs, hard reset obdII an reset abs -with rentable scanner ..THEN test run an monitor 02 readings an other readings such as tps,fuel trim,etc ..do that switch[ mentioned earlier] on cylinder wires too an see if misfire code follows it..
-but definately put all oem sensors an basic ngk plugs ,or basic champion- (not my fave-)in it!
I changed back to NGK basic an the firing went much smoother !! No miss..
Be sure you dont have air in abs system too..that will cause a lot of issues .. .

 

Certainly I am learning my lesson on non OEM parts. When I decided to start chasing the brake problem...... I received a bad brake light switch and a bad transmission speed sensor.

This week I will chase out the remaining vacuum leaks. I can drive the truck which is helping me with transporting stuff.

I am now taking this as a personal challenge to see this through. If I can get the codes gone.....I'll use it for 20 more 200 mile round trups and then dump it for a more reliable vehicle.

In hind sight........I should have spent the money of a newer truck...suffered the payment and sold it after a few months worth of use which would have saved me a huge amount of time.

We'll see how this goes

HK

 

Did you fix the problem yet Henry?