ive noticed spark knock since i dropped in the 3.4. there is no carbon build up so im thinking timing. what do you all think i should run? read my sig to see what i have done on it. im also getting an MSD blaser coil and 8mm wires.

 

in the same boat (although backing off the timing helps). Wierd part is that backing off the timing KILLS the low end torque. I'm still running lean too (probably a contributor). I'll fix it though...eventually.......

 

Just kidding I have been getting the 44 code since i got the car and since then i have checked tried everything i can think of and can not get ridd of it. Also it doesnt seem to me that i run lean...

I never checked my timing with a gun yet, i just kept adjusting it till it seemed best on and off the highway.

 

Yes, that will contribute to spark knock...

I notice you're both running mass-airflow systems.. did you keep the 2.8 injectors or switch to the 3.4 injectors? I keep thinking the 2.8 injectors should be fine since it's a mass-airflow system, but Ked85 swears up and down to use the 3.4 injectors even with MAF... this information is becoming rather important very fast since I've got decisive power over which injectors go into a 3.4 swap this weekend...

 

you must go with the 3.4 injectors.

injector equation is a formula of estimated power.

Will it run on 2.8 injectors, I bet it will, but your going to be very lean.

Have you replaced your knock sensor (guessing 44 is knock sensor)? Sure the rockers are on tight? Some of the s10 people get false knock from the cam/lifter/rocker assy they put in the engines.

Are you sure the wiring is fine to the sensor, and when bolting the starter back up, you didnt knock the sensor plug off?

 

The way it arrives at injector pulse width for MAF vs MAP is very different, Dale.. keep in mind, with MAF, it measures every gram of air that goes into the engine and supplies fuel for it, not via the VE tables.. I don't think the MAF vehicles even *have* VE tables. With a MAP vehicle like yours, yes, the 3.4 injectors are absolutely critical since it's doing everything based on VE tables.

 

yea im sure its spark knock, it will only do it under load. ive dealt w/ spark knock complaints for 4 years at a dodge dealership w/ the late 90s magnum engines.

im running the 3.4 injectors. the sensor wires are ok.

 

Only under load... well, ideally you'd start modifying your spark tables in the chip.. but it's likely that isn't an option.. Your other options are to start retarding timing in 2 degree increments until it goes away, or start running higher octane fuel. The 3.4 injectors on a MAF system should definitely not be running lean, so, pending a contradictory statement from a WB02 sensor, I'd count that out

 

I dont know maf systems, or anything about the ecm. All over my head.

I do know that on any ride, their is a formula that you go by to figure injector sizing. You tweak them by adjusting fuel pressre and injector pulse though.

(est power x .50) / (injector amount x .80) = lb injector you need.

Above is for a N/A engine, boosted uses different setting.

Check your knock sensor, check all the wiring to it. If you know your timing is to high (damn, I need to check mine) then adjust if back down for now tell you figure out the problem.

I'm having some sensor issues myself after the 3.4 swap, but I know I have some old elcheapo sensors from the last engine.

 

The V6 MAF cars aren't equipped with a knock sensor. When these guys complain about knock, they mean honest audible knock.

What base timing are you guys running?

 

But, code 44 is the lean condition code. I run 3.4 injectors, I still run lean. I guess I'll throw some 19# ford injectors in. I'm taking the car to a performance tuner monday, he'll fix it. Maybe even set me up with a custom chip......

 

try bumping up the fuel pressure before buying new injectors.

 

If you're gonna have it tuned anyways...yeah, just put some appropriate-sized injectors in, and let the tuner deal with setting it all properly.

Bumping the fuel pressure is the cheap way to do it. Lol...it's good for keeping you from going lean, but on a fuel injected car....well, the computer is used to having control of everything. And it's programmed to control injector flow through the injector pulsewidth.... Controlling flow through fuel-pressure is going past the computer....and the computer is going to operate that injector just like it's running stock fuel pressure. Because as far as the computer knows, it is. Let's just say the computer gets a little bit confused....and the car doesn't always run too great. This is from personal experience I'm saying this.

You say you're throwing a lean code...but are you actually running lean? With an old O2 sensor, it's fairly common for it to throw a lean code when you can actually be running very rich.

 

My buddy at the inspection station stuck a wand in my car's ****, and it was reading REALLY lean. Exhaust smells ultra lean as well. I imagine I could get some extra power out of the darn motor if it was running 14.7 like it's supposed to.

 

Just out of curiosity, what were the readings that you got that said lean??? The analysers all compute the a/f ratios, it's not a true, accurate reading since it really has no clue how much fuel and air is actually entering the motor. It has to guess based on the readings and if you are looking at that number, it might still be wrong. That's whay they don't print out the ratio on the VIR.
Post up your readings for me so that I can see exactly what you got...I am also looking into the 3.4 swap and what to know what kind of readings to expect off the bat.

 

FBodTrek's friend was probably using a wideband O2 sensor.. pretty decent level of reliability, though it would be better if read prior to the catalyst.

 

WB-O2's are great...if all of your emissions systems are working as desined. For instance, if you have a misfire, you are going to read high amounts of o2 in the exhaust, that might signal a lean condition on a WB-O2. Also, an Air injection system stuck blowing air into the exhaust stream will add too much o2 giving you the same scenario. Also, by reading his post, he said his buddy stuck a wand up there, that signals to me...smog analyser. Plus, you really can't tell anything by reading from behind the cat anyway, it masks soooo much from you that it's really unreliable for actual drivability problems. Don't get me wrong, if you are good enough and seen enough VIR's that you knwo what to look for, then yes, you can get a decent idea of what's going wrong, but you can never get an acurate a/f ratio from behind the cat. You have to look at the other gases to see where you stand. That's all I'm sayin'...