What O ring are you talking about in the middle of the intake manifold coolant hose?

Im going to have to try the smoke test as well to see if the new gasket I installed leaks. Im glad I wasn't the only one second guessing wether I got the right injector kit. The new pintle caps had me worried.

 

Right in front of the intake manifold is a coolant pipe that is the heater core supply (pipe comes out and curves around the passenger side of the intake manifold). I did not have to remove it to get the intake work done, but prior owner had left cables in a bad spot and I removed it to correct that issue. The pipe has one bold right below it on a flange that holds it in place (access down behind alternator). My pipe came out pretty easily, but I've read another thread where it didn't want to come out at all, and took extreme measures. The pipe is fitted with an o-ring to seal it up when it's inserted.

The truck is running pretty good so far. I got the back two O2 sensors replaced this afternoon. Still need to do the front two. Still have the brake booster line connector to fix as well. It's like a whole new vehicle with the injector work done though.

 

Just keeping some info together in this thread, in case anyone digs it up later.

Finished the O2 sensor replacements and got the exhaust manifold to pipe gaskets replaced.
Replaced the radiator yesterday to deal with broken bleeder pipe fitting, as well as another crack in the same area that was leaking

Truck is running well after all this, and while I still see a lot of maintenance work that needs to be done, the only engine-related issue is a slightly variable idle speed issue that seems coupled to the p0505 (idle control malfunction) code. It idles about 750-ish, but a couple times a minute it goes up to more like 1000rpm for a second or two and then goes back down. The code comes back if I clear it.

I've seen others report this issue, without clear resolution. I do not think it's the idle air control valve itself. PO included a remanufactured IACV, and it behaves the same with either installed. Seems more likely that there's still an intake or exhaust leak somewhere that I need to track down.

So I'll need to do some additional troubleshooting, but happy with the outcome of the intake work so far, and getting the truck on the road a bit to make sure it all holds up.

 

 

Well I just got done replacing the injectors with the refurbished ones I got off Ebay and that seemed to do it! If anyone is going to rebuild the injectors I would defiantly recommend getting a refurbished set. The extra 40 bucks for them is worth the possible headaches. Ill report back after a few more test drives and see what codes I have remaining.

 

That's great news! I'm still diagnosing the p0505 code. Have a few ideas on that to test out tomorrow.

In sadder news, I discovered that one of the right side exhaust manifold bolts is sheared off. It doesn't seem to be leaking, and it's sheared off at the head end of the bolt, so there's quite a bit of it sticking out of the engine head. Hopefully I can get it out of there without too much grief. Getting some new bolts and gaskets on the way. Guess I know what I'll be doing next weekend. And I just had the exhaust pipes disconnected in order to put new gaskets in the manifold to pipe connections...

 

I think I have the p0505 code cured. After much searching I found reference in another forum from someone who had the same issue after some engine work, and it turned out to be the throttle cable mount. They said since that is not a keyed bracket position, it made the throttle cable just a little too tight when they re-installed it. The solution was to loosen the bolts and let the bracket self-adjust to let any tension out of the cables. I did the same thing, and it's been idling smooth since, and no new code yet.

I'll need to drive it some more to be sure that was it, but so far so good today! I'm out of town all week, so it's shelved for the week. Hopefully I don't run into serious issues getting that exhaust bolt fixed next weekend...

 

Solved exactly the same issue (same codes) by replacing all of the injectors. Rebuild would work too.

 

Thats great. After having 3 discos with codes like that its always a sure fix to get those codes away, Cheers