how many others that have done the 3.4 swap keep throwing a code 45? this is the third time since january that ive gotten it. i know its running kinda rich, but i didnt think it was that bad.

 

First, check the oxygen sensor's wire and connector. Check the entire wire, from the oxy sensor itself, all the way up along the firewall to the main harness. If any part of that wire melts on the exhaust, it'll short out the circuit, and the computer will throw a code 45.

I had that happen once; the wire was flapping around and the connector melted on the exhaust. I was able to just replace the outer connector housing (Pep Boys sold the individual weatherpack connector pieces- the center pins, insulators, housings, etc) and then I made sure to keep that wire out of the way of the y-pipe!

I actually undid the screw holding the fuel tank's vent tube to the frame, slid the oxy sensor wire behind it,and bolted the vent tube back to the frame. That wire's not going anywhere now! If you were under your car looking "up" at the oil pan, with your feet sticking out from the front bumper, this spot is on the passenger side main frame rail, near the firewall- one 10mm screw holds the vent tube bracket to the rail.

 

ok, i checked it out, all seems to be good. that thing is a pain to find in spots. i pulled the o2, its all black... again. why would i keep running rich? timing is at about 11 degrees, timing chain is less than 10k on it, injectors arent leaking. i know the ECM is set for a 2.8, im just wondering if anyone else w/ a 3.4 has these problems. cause bigger injectors are going to make it run richer, but will it cause it to be that much richer?

 

How are the spark plugs? Pull 'em and see if they're all black, or if just one or two are black.

 

ill pull them tonight and find out how they look.

 

didnt get a chance to check the plugs tonight, a friend had some waterpump problems. ill try to check them tomorrow at work (really slow) or tomorrow night. any other thoughts TomP?

no one else w/ a 3.4?

 

I've been running rich, but I've got something else wrong too so my end isn't real valid I guess. Plugs keep getting oil on them. Starting to **** me off actually. Gone through too much with this stock *** motor to have it do this. New injectors, cam, lifters, timing chain, rings, valve guide seals, gaskets, replaced pretty much everything but the EGR stuff (diaphram functions). All that's left is the oil rings not seating right I guess. Compression rings are fine, has great compression. Honestly at the point now where as long as it's not fouling plugs (doesn't anymore, but did several months ago) and running at least decent... then I don't give a damn. [/rant] *breath*

So yea... I'm running a little rich too.


-Bud

 

'67, have you tried going to a plug with a hotter heat range?

 

I put some plugs for a 3.4L in it (different p/n at the parts store).. and it doesnt foul them, but still oil on them. What would you suggest I use? I'd thought about getting a better coil and stuff, but I don't really want to throw excessive money at the motor if it's fubar.

 

What was the part # of the plugs you put in?

 

I dont recall what type of plugs I have in there right now, but I want to say the more expensive Autolites

APP25 for 3.4L Double Plat. Autolites
APP23 for 2.8L DP Autolites (says not available too)

another thread with some plug p/n's in it: click

 

Well when you find out the part number of the plugs you have in the motor, then you can go from there to determine which heat range you have, and which heat range you should try next.