I replaced the intake manifold gasket on my '98 ZR2. Not too bad, but couldn't get the fuel lines off and the power steering pump/ac bracket wouldn't wiggle completely off, but I did manage to get the old one cleaned off, scraped and cleaned the surfaces. No leaks! I also put in a new radiator.

When I removed the distributor/rotor, I forgot to put a mark on them so I'd know where to align them back up when refitting them (doh!). I "kinda" remembered where it was by sight, and when I took it off I didn't move the distributor cap too much when I had it out, just a little back and forth. I saw that the distributor cap goes through about 30 degrees of motion, so about one hour's angle worth on a clock.

I put it back in where I thought it was and it seems to run just fine, EXCEPT it was giving a P0102 and P0340 errors. Unplugging the MAF plug smoothed it out but didn't get rid of the P0340.

DOH #2: Well, I forgot to plug in the wire going to the camshaft sensor that hangs off the distributor! I plugged that in and the car seemed to run better and got rid of the P0102 and P0340 codes (and now the tach works!), but I still can't plug the MAF in without the car bucking at idle and eventually shutting off. No misfire codes.

With the 3-pin MAF sensor unplugged, I can idle and rev the engine and it's very smooth and drove it around the block a few times and it runs great. Now it's giving a P0345 error.

Can anyone help please?

 

That would be a P1345 and that means you don't have the distributor back in on the right tooth

 

first you need to set the number 1 piston to top dead center then follow the steps in this video and you should be all set

 

Wouldn't the wrong tooth mean it wouldn 't run at all, or wouldn't run at higher rpm?

 

timing is way off

 

i had the same issue when my intake gaskets were done. i had a shop do the work and they took the distributor out the old school way which does not work well for these engines. i had to redo the distributor by putting #1 cylinder on compression stroke and lining up the marks on crank pulley then realign the markings on the distributor shaft and popped back in and poof no more code. old school way sucks

 

Actually, the distributor position is way off. Timing doesn't change with dizzy position on this engine. Timing is controlled by the PCM based on the crank position sensor.

Did you make the drawing with the timing marks? There's another mark that's easier to see when the water pump is installed, especially if you're under the car cranking on a wrench to turn the crankshaft. There's a tab on the lower cover that lines up with the mark on the balancer/damper at about the 5 O'clock position. That mark lines up with the tab I highlighted in this picture:



Both the top and bottom marks line up when cylinder 1 or 4 is reaches TDC at the end of the compression stroke.

To find #1 for certain, the easiest way is to look at the dizzy. If it runs at all, the rotor will be in the neighborhood of #1. If you don't trust the dizzy at all, the best other way I've found is to pull the passenger side valve cover and watch the rockers on cylinder #4. Right after the exhaust valve closes on #4, and right before the intake valve opens, that's TDC on full compression for #1.

As for the codes, P0340 and P0345 are CMP failure codes. I've seen P0340, but I don't think I've ever seen P0345 before (that's a bank 2 CMP failure). There's only on CMP on this engine.

P1345 is a CKP/CMP mismatch code, and that indicates the dizzy is installed out of position. The fix for that is to position the engine at TDC for cylinder #1, check the dizzy and make sure the rotor points at the "6" on the frame. If it's off, pull the dizzy, align the marks and try again. Once you have it on the correct tooth, the P1345 will go away. You should still check the "CMP Ret" or "CMP Ofs" with a good scan tool and get that as close to zero as possible. It should be zero +/- 2 degrees. If it's off, you can get a small block Chevy dizzy clamp (like Mr. Gasket 1009, about 7 bux almost anywhere), or if you like work, enlarge the hole on the stock clamp with a die grinder (or a Dremel tool) or round file.

 

Fixed it! Great video! Lined up the timing marks (noted the two notches as in the image) on the crank flywheel and the engine. Indeed it was off and not pointing at the "6" embossed on the rotor! Hard part was getting a long screwdriver down in there to move the oil pump notch to the correct position. I did it with my phone as a magnifying glass with light in one hand and the screwdriver in the other.

SES light went away, but it runs a little rough at idle, and will die, but nowhere as bad as before. Truck didn't run for over a year and probably just has bad/old gas in it.

Thanks you guys, much appreciated!

 

So I forgot to put back the PCV valve and hose. Rough idle suddenly turned smooth!

 

Thanks jeff