Oh Boy, do I need help!

[artbuc]

Just finished replacing valve cover gaskets and Coolant by-pass hose on my 99 Avalon with 1MZFE V6. Used new OEM intake manifold gaskets but reused air plenum, throttle body and EGR/EGR pipe gaskets. I was concerned about vacuum leaks and also concerned about electrical because I was pretty rough on the wiring harness. Well I got both problems! Car started right up and runs good ecept a little rough idle and high idle rpm. CE light came on and showed coded P1300 and P0171. I sprayed some MAF cleaner around throttle body flange and EGR flanges and got increased engine speed. I guess if it is sucking enough to increase engine rpm I guess it is sucking enough to throw P0171, right? Could not get any increase in rpm when I sprayed around the mating flange between the air plenum and intake manifold.

My igniters are working fine so I am guessing I broke a wire somewhere. P1300 says the ECM is not getting a return signal from the igniters.

I will install new EGR and throttle body gaskets to see if that stops the vacuum leak. I will look for where I lost continuity between the igniters and ECM. Any other ideas. I need all the help I can get. Thanks.

 

[artbuc]

Ok, I now am the official dunce of BITOG. The 4 bolt holes on the throttle body gasket are square but it there is only one orientation that seals. Rotated gasket 90 degrees and air leak is solved. Don't think I'll see P0171 again. Idle speed is now where it should be.

I'm going to clear codes and see what happens. I don't see how an air leak could throw P1300 but I don't want to start searching for a needle in a haystack unless I have to.

 

[morris]

sounds like the square bore carb on a spread bore manifold, thing.

 

[yonyon]

If your P1300 comes back, do this before you jump into the wiring diagrams:
#1 Make sure you didn't leave a ground strap disconnected or poorly connected.
#2 Check for any damage to the coil boots or wire boots.
#3 Disconnect and reconnect each coil and listen for the click. You can do this while doing #2.

If it doesn't:
Be happy. A non-ignition caused miss such as a lean miss can cause a feedback issue and generate this code.

 

[The_Eric]

Originally Posted By: yonyon
If your P1300 comes back, do this before you jump into the wiring diagrams:
#1 Make sure you didn't leave a ground strap disconnected or poorly connected.
#2 Check for any damage to the coil boots or wire boots.
#3 Disconnect and reconnect each coil and listen for the click. You can do this while doing #2.

If it doesn't:
Be happy. A non-ignition caused miss such as a lean miss can cause a feedback issue and generate this code.


To elaborate on yonyon's reminder to check grounds... On the 1MZE-FE, there are something like 3 or 4 ground wires on the intake. On on the side rear left (as you're looking at the engine) and (I think) 2 more on the rear of the intake by the firewall.

 

[artbuc]

Originally Posted By: The_Eric
Originally Posted By: yonyon
If your P1300 comes back, do this before you jump into the wiring diagrams:
#1 Make sure you didn't leave a ground strap disconnected or poorly connected.
#2 Check for any damage to the coil boots or wire boots.
#3 Disconnect and reconnect each coil and listen for the click. You can do this while doing #2.

If it doesn't:
Be happy. A non-ignition caused miss such as a lean miss can cause a feedback issue and generate this code.


To elaborate on yonyon's reminder to check grounds... On the 1MZE-FE, there are something like 3 or 4 ground wires on the intake. On on the side rear left (as you're looking at the engine) and (I think) 2 more on the rear of the intake by the firewall.


Yep, I think I got all of them - even cleaned them up really good to make sure I got a good ground contact. I'll look there first if P1300 comes back.

 

[artbuc]

Originally Posted By: yonyon
If it doesn't:
Be happy. A non-ignition caused miss such as a lean miss can cause a feedback issue and generate this code.


Looks like you were right, Yonyon! Been driving a few days now and no P1300. Also no more oil leaks and the car is running great. Yesterday I thought I might also have a camshaft seal leak, but it was just some residual oil draining off the frame.

Thanks to all for your helpful responses.