mt_goat

Great, glad you figured it out and great writeup. Now get ready for the main disadvantage of a 3.4 over the 3.slow, (your tires will wearout faster)

fillsrunner4

great to hear you figured it all out and have been able to drive is so cheers, drink it up and great work


Now its my turn

breknraj

So, Steve, did you have the theme from Rocky running through your head when it all came together?

Congrats! I know that you're gonna love having it!

Elvota

I can't imagine what a supercharged 3.4 must feel like. The one I got really screams compared to the 3.0.

Definitely. We'll have to figure out what your issue is. Do you have a specific thread going about your problem? I saw your writeup about the truck... looks like you have done a major amount of quality work so far.

I was amazingly stoked, that's for sure. We'll have to stop by next summer when we are in Summit county and compare our swaps. Does that sound to personal??

However yesterday, on my 2nd drive... I did have another setback.

Sitting at a light, happily feeling the 3.4 purr in front of me... I suddenly noticed a massive amount of steam escaping from my cool hood cut.

Luckily, the light just went green and I flipped a U-turn... pulling off and shut it down immediately. There was coolant smoke everywhere and a huge puddle dripping beneath. "What did I screw up now?" I wondered.

After things cooled off a bit, I noticed my heater valve had broken. When I put this thing together it did look a little marginal, but I decided to stick with it as it was the only one I had readily available. Bad move.

Old one on left, "new" salvage one on right:



You can see the input broke right off. I got three, that's right three more from salvage this morning and chose the best one for a replacement. Put it all back together, filled the coolant and brought it up to operating temperature. Everything checked out, so after several short loops around the neighborhood I decided to try and take it out to the highway.

Simulated high speed driving experience :



I can now merge onto the freeway with speed, even on several inclined on ramps in the area. Could easily hold speed as well. Will have to get used to watching the speedo again. I really need to get my tires balanced. I haven't gone above 70 for ages... now with the 3.4 this is an easily achieved velocity.

Bring on the road trips!! Bring on the hills!!

If anyone out there is reading this and still on the fence, really consider this swap before putting much more money into a 3.0. I wish I had.

fillsrunner4

I dont have a thread specificaly about the problem yet. i should have it down at my buddys shop to hook it up to a good OBDII reader. Im thinking right now my MAF is bad but still not 100%

Great work on yours also great thread. I remember i tried using the 3.4 heater control and i couldt get my dash switch to work with it thats because the 3.4 and 3.0 were different thats fixed and works now so im good on that

Great work and stay posted to my thread becuase ill post my build of the 3.4, transmission and more.

Elvota

Got the resistor soldered to the back of the tach this afternoon. I tried to take some pics but my camera was acting up.

Got the 10k OHM, 1/4 watt resistor from the local Radio Shack. Five of them for 99 cents. Cheapest part of the swap so far.

Pretty much just followed mt_goats lead (Pics at bottom of page 2) so any additional pics would have probably just been repetitive.

I also put a shorter belt on the alternator. The steering shaft was clicking on the alt. case during slow speed/ high load turning situations. I ended up using Autozone belt part number 420K4. That's actually a 42" belt, for those without Autozone in their area. Ended up using a 420K4 belt for the power steering as well. Since I don't have my AC yet, I can have one 42" belt for a spare and cover both bases. Very nice.

Got the OBDII port wired up as well today. Got a scanner from ScanTools.net to connect the 3.4 to a laptop for some real time data. It's a single protocol device so it only ran $50. I'll post up when I find out how well it works (if it works ).

I did find this gadget in my searching which seems like it might be pretty useful to have connected full time: (LINK) I have no idea how well it might work, but seems like a great thing to have in the future.

Have about 350 miles since my last hurdle of the coolant issue and things continue to be working well. Can't believe the additional power and torque I have gained. Strange to sit behind the same wheel... yet now have a vehicle that responds so well to the skinny pedal.

I'll have to get used to watching the speedo and being able to pass people when I want to.

fillsrunner4

Lucky Bastard truck looks sick in the Mag. I cant wait to see mine in one too. Thats my life long goal. Looks great

Elvota

Yes... but your rig actually has a chance of getting in. Very impressive amount of work you have done.

fillsrunner4

Thanks dude yours is bad ass as well youve done some great work too. Will both get there. We should meet and wheel at some time. Im so close Stay tuned into mine cause ive got tons more work to do keep yours updated as well

Elvota

Still really enjoying the 3.4. Great on road and off.

I kept getting a CEL and when I hooked up my OBDII scanner I had a code P0420 which means my cat was operating below threshold.. at least according to the computer. I reset the code but it came back a few days later.

My guess is I kept getting the code due to the fact I have a hi-flow cat and that doesn't meet within the parameter of the OEM cat. Or my O2 sensor could be bad. Either way, JasonD was nice enough to help with with a permanent fix.

Basically, the second O2 gets bypassed by building a small circuit board. This circuit board sends a constant and correct signal to the ECM and bingo... no more CEL. Has been working for a week now and still running code free.

Here is a link the the schematic:
http://www.vfaq.com/mods/O2bypass.html

JasonD advised me that he had just left the two wires controlling the heating component of the O2 connected to the O2, so I followed his lead. The link above shows how to bypass the O2 sensor completely, but this line had me spooked...

"This heater element flows around 1 Amp of current so you'll need resistors that can dissipate at least 12 Watts of current. Don't scrimp here as under-rated resistors could set your car on fire."

Fire bad... simplicity good.

First, to Radio Shack for some parts:





Basically, you need 1 Mega-Ohm Resistor and 1 Micro-Farad Capacitor. To be honest, most of this electronic stuff is Greek to me, but the helpful Radio Shack fellow sold me what I asked for.

I got a little job box to put the completed board in. However the board they sold me did not fit, so I had to trim it a bit with a Dremel. The resistors come in packs of 5, so now I have 4 extra that I will most likely never use.

Then, you have to run two wires in parallel to the resistor and cap:





When that's all soldered together, you stuff it in the box:



So now I spliced one wire of this box to pin OX2 on the ECM and the other to the O2 sensor ground wire. I just spliced into the harness at the engine bay. In effect, I took the O2 sensor out of the loop and in turn replaced it with the constant correct signal be sent by this box.

Don't ask me how it works... could be voodoo magic for all I know. Something about keeping the wave signal constant and within the range the ECM wants to see.

mt_goat

Good work! That's a lot cheaper than what I did: http://www.urdusa.com/product_info.p..._id=1230100014

Elvota

Thanks. This whole swap has been based on a budget that is very slim, so I was forced to cut corners whenever possible.

I forgot to mention to others out there that the above O2 mod was all done under $10... but we'll see how well it works over time.

In theory with no codes yet I should be good to go.

I'll update again if something comes up.

jasond

Glad it worked for you, I've got about 500 miles on the one that I did so far and have yet to see even a pending code.

Elvota

Seems to be holding so far for me as well.

I am close to 500 miles as well with varied terrain. Everything from highway driving to super slow speed rock crawling. Really appreciate the help. Thanks again.

isaac338

just read the whole thread - awesome swap. just for your info, whoever suggested that circuit to you told you to use resistors that could handle 12 watts, or 1 amp of current. you bought 1/4 watt resistors, which are obviously far less capable of carrying such high amperage (they handle about .02 amps, or 20 mA). they are likely to combust if they get hot enough, or at the very least explode. and believe me, they'll get very hot.

check ebay for surplus guys, you should be able to get some pretty heavy duty wire-wound resistors that'll handle such large current flow.

Elvota

Thanks for the compliment.

Believe me, with my limited electrical knowledge I'd be the last one to get into a debate about all this...

But I believe the 1 amp resistor you are referring to is for the heater side of the O2 circuit. The link I posted shows how to eliminate the entire O2 sensor.

What I did with this mod was to bypass the signal side only.

So, the high amperage (heater circuit) is still connected to the O2 sensor which is still attached behind the cat. Therefore, the lower rated resistor I used should be adequate.

What say you??

isaac338

i don't know anything about the truck's electronics - all i saw was your post where you quoted "remember to use resistors that can handle 12 watts", followed immediately by a picture of 1/4 watt resistors but rereading your post, if you only have small amperage going through those resistors (read: signal only), you'll be fine, i bet.

run it till it pops, i say. carry an extinguisher

i tell you though, reading this thread is making that 3.4 sound more and more doable..

anyone driving from BC to NS and want to make a couple hundred bucks hauling a motor for me?

Elvota

Yeah, that's what spooked me at first, but then I understood you don't have to mess with the 1 amp side at all, just the signal side.

So far so good and I've got maybe 600 miles on it now. I'll post up if something goes wrong.

And you are right, this swap is very doable. If you can get a 3.4, you should definitely go for it.

Jason4X4

well, if you want to get rid of one of those resistors, pm rayl82, we are about to start his swap, and could use one to make an o2 bypass too....

Elvota

PM sent. You guys can definitely have a couple for free, but I think they only where $1.75 or so for all five to begin with. Might not be worth the gas to come pick one up.

The entire bypass is under $10. Pretty good when the cost of an O2 sensor is at least 7 times that, and you still might get a code. Plus this one will send the right signal comparatively forever.