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3vze Piston removal Enlightenment and idle surge question

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Old 04-29-2013, 11:32 AM
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3vze Piston removal Enlightenment and idle surge question

I just replaced my 88 3.0 with a 91 due to a cracked block. I put the motor in to find out it has a knock... Grrrr!!! I replace the rod bearings. Still knocking. Checked the main bearings while it was still in the truck, (had to grind off the lip on the rear seal retainer), but no sign of wear.

So once again i pulled the motor, but this time it went very smooth. Probably because of all of the bolts being broken loose and the know-how from the previous experience. I thought to myself, "Its got to be the wristpins. What else could it be?" The head gaskets were resently done and i really didnt want to pull the head off.

I decided to try to pull the pistons from the crank case. I had my previous engine to test my theory so i figured, "Whats the worst that can happen? Its no good anyway" So I tore into that sucker like there was a million dollar bill in the middle of it. After pulling the crank, which is necessary for this procedure, I grabbed a rod and gave it a tug. Sure enough that bad boy popped right out. Now lets try to reinsert this thing... After a little bit of wigglin I got it back in with no damage to the rings.

Now with the new motor on the engine stand it tore into it with hopes of finding the source of the knock. Well once i got the crank out i gave each of the rods a jiggle to look to excessive movement. Nope...

After scratching my head and looking in there for a good while I see this.

Not one but two bent rods. #1 & #6 cylinders. Im assuming when the fella blew the HG he continued to drive it for some time. Or maybe drove it through a pond or somethin like that.

The new motor was previously overhauled so the pistons were oversized. I took two of my old rods and the two bent ones to work and used a press to push out the wristpins. I put everything back together and fired her up. Sure enough there was no knock. Everything sounds great, no knock, no valve chatter, oil pressure seems abit low. Has an oil leak at the rear of the motor. I hope its not the rear seal, but probsably has something to do with the pcv. The motor was upsidedown on the stand and im sure some residual oil got in it.

My question is; Its hard to start when cold. It gets close to killing the battery. Once its fire up it runs great. Once it warms up the idle surges about 400rpm. When I hit the gas it revs up smooth and it drives fine. But once you come to a stop it tachs all over the place. If i let it do it long enough it will stall. I had these same symptoms on my 22r 2wd and it was a stuck EGR. I know my EGR is good on this motor because it worked fine on the last one. That goes for all of the potential subject parts. Could it be that i have the vac hoses connected wrong and one of them is holding the EGR open?

Throwing codes 22 (CTS) and 43 (STR) I had an issue with the CTS before and replaced it but that didnt clear the code so i assume i have an open circut or short but what of the code 43?

P.S. For the record it is possible to pull the pistons from the crankcase but im not sure while the engine is still in the truck. Maybe if you pull the tranny you can get the crank out... but you also need to remove the timing belt to get to the oil pump. I didnt really feel like dealing with limited work space. I cant think of anyother reason to do it this way other than wanting to save a few hundred smacks on gaskets and bolts

Note: At the bottom of the cylinder hone there will be a carbon buildup where the piston doent touch. I recommend cleaning it with solvent. You cannot use a ring compressor as there is no room. I tilte the piston so on side of the ring sat in the cylinder, then using a rigid tool with a softer than metal edge, compressed the ring and rocked the piston in. Doing this one ring at a time
Attached Thumbnails 3vze Piston removal Enlightenment and idle surge question-rod.jpg  
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