so, I just got my 3.4l w/supercharger running this morning,
Idles great. but I gave it a snapp throttle to see how it sounds and it back fires and blew my muffler in half.
I think I figured out why it blew my muffler.
I had my fuel return line hooked up wrong and was running 65psi of fuel prssure to the injectors causing access fuel to build up in the muffler. after fixing that.
I snap the throttle and it sounds very lean at high RPM's.
I need to hook up my OBD2 port still,but just hoping you guys would have some ideas.

 

You need to get a wide band hooked up to that thing, to make sure your air fuels are in check.

 

i want to see the "blown in half" muffler

 

When i first got my truck running it did the same thing, make sure you have your + B wire from both body harnesses together. I had one coming for the computer and one from each body harness. I had the ECU one tied to the 91 body harness. When i tied both body harness ones together it fixed it. Now i have all three together.

 

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well, I think I already have it set up that way, I didnt at first, and it would start then die right away, then I hooked those three wires up and It starts and runs. But still seems like it goes very lean off idle. I really need to concentrate on getting the OBD2 set up. Let me know if you guys have any other ideas

 

Ok, I got my obd2 setup going.
I'm getting two codes....
They are both shft solenoid codes because this motor and ECU were coupled to an automatic trans.
So those codes are not telling me anything.

here is what is happening. starts and Idles great, runs pretty good coming from a stop and if I slowly get the RPM's up it seems pretty good.
but... if I mash the throttle the engine just chokes, Its like its not enrichening the mixture.
I'm wondering if I need a different MAF sensor that goes with the supercharger, or the injectors are too small. or I have something wired wrong.

 

Damaged or defective spark plug wire/wires. Under mad boost the spark finds a way to get by any week points in the plug wires.

 

I feel like my spark plug wires are OK. I'll ohm them out tomorrow. It really feals like my injectors are cutting out or not fully enrichening. I pulled the fuel filter today to see If maybe I'm not getting the volume of fuel the system needs ( I could barely blow through it)
replace fuel filter with no change. My fuel pressure seems to be OK at idle and the regulator is increasing pressure when it looses vacuum. I should probably do a dead head pressure test. Does the 3.4l work off the same fuel pressures as the 3.0l.
thanks guys

P.S. I still have not set any other codes other than the shift solenoid ones.
pretty dang frustrating.

 

Do you have a 7th injector installed? Are you sure its going lean and not rich?
Any smoke out the tail pipe? Back firing and blowing up a muffler points to excessive fuel being combusted in the exhaust pipe, possibly due to timing, bad valves or excessive fuel, perhaps a stuck injector. Have you checked timing at idle and advance? Do you have a boost gauge installed?

 

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I'm not running a 7th injector, when I blew my muffler apart I was running rich, I had my fuel return line hooked up to the wrong line going to the tank (making my fuel pressure jump to 70psi) I've fixed that, fuel pressures seem to be normal,I have not checked my dead head pressure yet though.
I dont have a boost gauge hooked up yet.
I feel like it wouldn't run this smooth at idle if my timing was off.
the motor only has 80k on it so i doubt i have any bad valves.

still no codes set

 

You do have it where the ecu keeps its memory, correct?

The reason that I ask that is because that ecu takes a few trips before it starts to learn just how lean it is getting with that supercharger and has to adjust the fuel trim. That is the reason for the 7th injector (that and the injectors are pretty much maxed out without the 7th injectors help) I did some research before I went to install my supercharger (which I still havent done) and found out that alot of guys are running the supra 7m-ge non-turbo injectors with the supercharger as they are able to keep up better than the stock ones.

 

well, I hadn't hooked up my charging system yet, so the truck has been running solely off battery power(just on test drives). So, I got it all hooked up this morning and my running issue totally went away.
I'm not sure how it ties in, maybe I didnt have enough power to the coils at high RPM's
weird....
this thing runs great now..

 

whoa you are in eugene oregon? I'd like to look at your setup sometime. I just swapped a 97 into a 90 4runner.

 

hey man, you could definitely come check it out. All I have left to do is clean up my rats nest of a wiring harness, and setup my evap setup. I should be driving full time by this time next week. I also need to figure out my A/C system, I had a shop here in town make me some lines. and eventually I'd like to get the cruise control going. Just send me a message when you want to come check it out. How far are you on your project.

 

Sorry to be OT but:
Have you noticed anything like your computer isn't running correctly because it is not receiving any trans info?

I want to go grab a motor but haven't found this answered clearly.

3.4 swap with an auto ecu in a manual truck.

Thanks bud

 

The 3.4 with an auto ECM running with a manual trans. will give you several codes due to the fact that the computer is looking for signals from the AT.
P0710, P0758, & P0773 are the codes that I am getting with mine. These are all codes related to the AT.
I have been driving my 93 this way for about a month now and it does not seem to affect the running of the engine at all from the best that I can tell.

 

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Well, So far this truck is still in the test drive stage of its life, should be my daily driver by this time next week.
my check engine light is always on due to Shift Solenoid codes being set, I'm taking the bulb out. But it seems to run just fine

 

The codes that I listed above are all Solenoid related as well.

My CEL stayed on all of the time too, so I removed the light. I can always still check for any codes with the OBD2.

 

Hey mechanic man, I am pretty much done. I have around 1000 miles on the motor now. I also need to get the a\c going, and not sure I am putting cruise back on. Wish I had the a\c for this weekend huh! going from 50's to 60's to 80 is going to suck!!!

 

Good to see that you have her running. It's inspiration to me to finally take my 3.0 out. The thing just won't die, and I'm having the darndest time taking out a perfectly good toyota motor that has been with me for 17 years.

Not that you need the confirmation, but yes not having the charging system up and running would definetly cause what you were experiencing. Since the 5VZ fires two coils at once, it is a wastefull sytem that requires alot of power to run. When you put a load on it by stabbing the throttle, the system couldn't keep up.