Try this , http://dodgeram.info/tsb/1998/18-48-98/18-48-98-v8

 

49+ PSI on the rails at all times. Still missing, worse than ever at .25 tank. Cant get the fuel pressure to waiver at all.

Is there a particular brand of plug wire that may be better than others? I cant recall but I think I got these at advance auto, and a buddy just had to replace his advance plugs on his toyota because they leaked spark all over...

I am thinking of going with NAPA Gold.

 

just got done with that wire routing bulletin, no diff.

 

So, I replaced the wires with OEM ones, the cap and rotor with NAPA Premium. I spent 4 hours switching the wires around to make sure they comply with the tech bulliten.

Still getting P0300, P0305, p0306 the minute that it achives closed loop, and its idleing. the idle is very rough.


So I did the plenum vacume test. no vacum or pressure at all..

Checked the intake vacuum, its at 15 inches. Should it be higher? My gauge says this is because of "late timing".

So I tried to check the timing. Put chalk on the mark, cant find it from number one.

 

Oh, I did a vacuum leak test using a unlit propane torch. No signs of a leak anywhere.

This is really really starting to annoy me.

My 72 olds with HEI is way easier to figure out....

 

Are you fouling any of the plugs at all?

What gap are you setting them at?

Both of these ideas are probably not a viable clue, but I am just wondering out loud. With me, that's a dangerous thing....

 

So I broke down and did some thinking....

Thats dangerous for me too. ...

Anyway it all started 2.5 years ago with a P0305.... So as a last resort. I ran a compression check on #5--- 50 psi.

That including a hiss and a steady but low vacuum of 15 Inches tells me exhaust valuve is not working. could be a broke spring or a burnt seat.

Ideas on how to diagnose? Take the cover of the valuves? I have no clicking or ticking, just a hiss on closed loop idle. It also does vibrate a lot above 72 mPH.

Whats you guys best guess on the value of fixing? is this going to cost an arm and aleg?

 

I hooked an air hose up to the cylinder and removed both rockers. Got a hiss out the exhaust. no visible signs of a broken spring.

Both the intake and the exhaust seem to be about the same strength. no bubbles in the radiator.

So I dont think its the head, must be a burnt exhaust valve.

Put it back together, but didnt route the wires just right, and now its throwing p03xxx for 45678.

ugh. I want my 86 318 back!

 

So both heads have cracks in them between the valves. I am having two new heads installed.

This explains why I couldnt get it to work with electronic tuneups.

This is disappointing, the truck is nearly new (77K miles) and has never been over 200 degrees.

 

what did you do, just pull the heads to check them out?
did you check compression on all cyl ?
did the cracks match the low readings ?
how many cracks?
77K is really low. you're probably just unlucky to get 2 weak castings on the same engine. it doesn't really matter though whether its 1 or 2. once you've got them removed, it makes sense to replace them both anyway. you doing the work or having it done ?