Well, you may remember my first posts. I'm the owner of a sick 2000 Bravada that was overheated and not running correctly.

So the tear down is more or less complete. The heads have been removed and have been delivered to the machine shop to be cleaned and tested. Hopefully the heads are the problem, and hopefully they can be rebuilt for a decent amount of money. A few pictures of the tear down are below.

Can anyone tell me if this is the old or new injection spider? If it's the old one, what is the part # of the new one? Should I get Delco, or Delphi?

You can't tell in the pictures, but I can't believe how much gunk was in this engine. I suspect the previous owner didn't take very good care of this. I just hope my piston and seals are ok so that this head rebuild will not be in vain!






Here I'm starting the tear down.



Here is the tear down to the injector.



Finally with the heads off

 

Great pictures, thanks for posting. That is the old style of fuel injection.

The new style is DELPHI Part # FJ10565 {#FJ1056511B1}
SCPI to MFI Conversion - Complete Assembly

RockAuto $241. Amazon $174

 

Cool, thanks for the reply.

I got a call from the machine shop. Looks like they need a little resurfacing and a valve job. He said possibly a bit of welding on the exhaust area. I got quoted $350 bucks, this includes the charge to clean and inspect. He also gave me a decent price for a gasket kit and head bolts $90 total for the bolts and a full Fel-pro gasket set. Probably not the cheapest in town, but I know this place does quality work so I don't think I made out too bad.

Here's hoping my pistons/seals are still in good shape.

 

I have just ordered the spider from Amazon. I can't believe that price. Pretty much everyone in town is over $300 bucks. I just paid less than $200 with 2 day shipping.

 

Something I just remembered, but forgot to ask about was the oil pressure. The gauge was dropping below normal at idle.

Would the heads cause the oil pressure drop? When you step on the gas it jumps back up, but drops back as soon as you let off the gas. There also seemed to be oil leaking from somewhere pretty high on the engine toward the back. When I was pulling the heads it seemed like some oil was accumulating around the distributor. The valve covers didn't seem to be leaking, but I couldn't tell for sure where it was coming from.

What is in the distributor area besides the valve covers that could be leaking oil? Is there some kind of oil valve, or oil sender?

 

FAIL! Did I just waste weeks of my life?

So when I started this adventure, the car had P0300 (random misfire). The car had been overheated.

The following is true:

Had the heads rebuilt.
New water pump
New belts and hoses
Cleaned out as much engine gunk and carbon as possible
Replaced head gaskets and manifold gaskets.
Cleaned and lubed the EGR
New MAP sensor
New remote/cooler oil lines
MPFI spider upgrade.
Oil change
Power Steering fluid change
New distributor, rotor, cap, wires, plugs

Got it all back together, fired it up. P0300 random misfire. That was a lot of work for nothing.

So I need to follow the service manual's troubleshooting steps, but this involves watching the "misfire counter" which my scan tool doesn't have.

Can a person rent a scan tool that counts the misfires? Where do I rent one from?

Let me know what else you think may be the problem. I hate to think the piston seals are shot? I'm about to drop back 10 and punt on this thing.

 

What brand of distributor/cap/rotor did you use? These trucks are VERY particular about their ignition components.

Also, did you set the CMP Retard after installing the new distributor? CMP Retard should be set to 0 degrees which is accomplished by leaving the distributor hold down bolt a little loose and moving the distributor within its hole through the lower intake manifold while observing the CMP Retard with a scan tool.

It should be mentioned that whenever the distributor, CMP sensor, CKP sensor, or any other hard part responsible for timing between the pistons & the distributor (crank, timing set, cam) are changed, and the CMP Retard has been set to 0 degrees, a CASE Learn should be performed to calibrate the PCM to the new components for precise control of ignition timing.

What caused you to tear it down to the cylinder heads? Did a compression test show signs of valve seating issues? Sounds like you got a good deal on having them reconditioned though.

You could inquire at your nearest Autozone. I think the one near me will loan a scan tool. Their more advanced ones though, they pretty much have you pay for it and then you get your money back when you return it.

 

Thanks for the reply.

I think the Distributor is "Cardone" brand. I put this one on there, because the old one was stripped out. The wires, cap, and rotor are BWD brand. It was running ok with these parts before the overheating. They were lifetime warranty so I swapped them all out for new parts (same brand) just to rule them out.

I did a leak down test before having the cylinder heads reconditioned. As far as I could tell the leak was coming from the throttle body, which I attributed to leaking valves. I didn't hear any air coming from the exhaust, or oil filler tube, nor did the car smoke or knock, so I assumed the pistons seals were ok (perhaps a very wrong assumption). I also did a compression test and the compression was rather irregular across the board.

I did not set the CMP retard to 0 degrees, this is something I will try. Is this something a lower end scan tool is capable of? I'll have to check the manual. I will also have to look up the procedure for a CASE learn.

I'll report back as to what I come up with. The GM shop manual has a list of troubleshooting procedures for a P0300 code. This includes things like spraying the wires with water to see if the misfires increase with moisture and doing other things to see if any of them causes the misfires to go up faster. Again, my scan tool doesn't count the misfires, so that's why I need something more advanced.

 

Toss the BWD parts and get AC Delco. As Kyle mentioned, these engines are really picky about their ignition parts.

 

They worked before the overheat and were free to try new ones with the warranty. If I had a scan tool I could tell pretty quickly if it was any of those things. I don't want to spend the money on a bunch of Delco parts if those aren't even what's causing it. Those Delco parts aren't going to help me sell it if it turns out being the piston seals.