Well im going outta town this weekend hunting so no work on truck. next weekend gonna replace o2's. It seems that the longer i drive it the worse it is. drive to work its great. to lunch its great to ok. back home, stalls when i get off the highway and lopes. Drove it to softball later last night and was total crap. I cant figure it out. so annoying.
Another thing to consider, every connection. I know those clips on the fuel injectors are usually broken. (Mine has like 5 out of 8 broken) So make sure its definately getting a good connection. Did you tighten the bolts that hold the main harness and engine harness together good and snug? Just tryin to give you some more options to look at in-case o2's don't fix it. But i think it has got to be a sensor of some sort. So hopefully o2 fixes it, if not, try checking the coolant temp sensor for the ecu, maybe it is bad and thats why it runs good cold and worse when warm.
well new discoveris today. im so lost. truck is running like crap. some white smoke outta tailpipe (intermitten), shakin at idle loping like crazy stallin etc. get home, truck stalls out of course. start it and it dies. do that couple times to see if it will stay on without giving it gas. it doesnt. then i unplug the MAF. start it. stays on! wtf. then i unplug the TPS while running and it stays on!!! WTF! so its running with just the IAC plugged in. no TPS no MAF. plug in the MAF while running, no change. Smells like crap. theres a deep humming coming outta the intake at the air filter. so thats freakin wierd. F this thing
problem is finding one that will work on it. they all dont want to touch it becuase its "custom" i gotta ask around. got an email into blow by racing. they know there sh*t so if anything im pretty sure itll go there
Doing a little reading today and thankfully with the help of that scan tool. My ECM is acting in a "closed loop" which from what i can tell is a good thing. So this goes back to a tuning issue. The only thing different that I have done since i picked it up was go back to the stock intake tube, thats it.
from mustangs and fast fords;
"So what happens when the engine is running rich and there is no oxygen in the exhaust? The ECU will assume that if there's no oxygen present in the exhaust, then the A/F ratio must be rich. At that point, the ECU makes a conscious decision to lean the A/F ratio, that is, until it reads oxygen in the exhaust again. At that point, the ECU knows it went too far (it's now lean), so it will richen things up again until the oxygen disappears, but now it's rich again, so the ECU will again lean things out, and so on. In CL mode, the ECU will continually cycle the A/F ratio lean, then rich, over and over, hovering the A/F ratio closely around the stoichiometric point."
That is why it is so intermitten with the loping at idle etc. My problem is i have no idea what is making it run rich to begin with. It has a new MAF, new TPS, and new IAC. All the things that sense air intake etc are BRAND NEW.
alright so before i go and drop 120 on o2's i registered for autozone online. wow great info. check this.
codes are stored after 3 faults of same sensor. I unplugged and plugged in the MAF and started the truck a bunch before i pulled the codes. that could have caused the p0113.
Trouble Code: P0113
Intake Air Temperature Sensor Circuit High Input
IAT sensor signal circuit is open (inspect wiring & connector)
IAT sensor signal circuit is shorted to VREF (5v)
IAT sensor is damaged or it has failed
PCM has failed
Trouble Code: P1121
TP Sensor Inconsistent With MAF Sensor
Air leak exists between MAF sensor and the throttle body NONE
MAF sensor is damaged or it has failed POSSIBLE CRAP ONE FROM AUTZONE
TP sensor is not seated properly NO
TP sensor is damaged BRAND NEW
Trouble Code: P1132 and P1152
Lack of HO2S-11 Switching, HO2S Signal High Input
Check air cleaner element and air cleaner housing for blockage MAYBE, OLD BUT CLEAN FILTER
EVAP vapor recovery system has failed (canister full of fuel) HOW DO I CHECK??
Fuel pressure too high, contaminated or leaking fuel injectors NOPE
HO2S is fuel contaminated, or coated with silicone or moisture I DID USE SILICONE RTV TO INSTALL INTAKE SPACER. SO POSSIBLE.
What is confusing me is;
Is it the bad O2's causing the P1121 issue by reading bad there for adjusting incorrectly?
Is it the P1121 adhusting incorrectly and making it rich and the O2's are actually good?
I am thinking the first because the causes of the P1132/1152 do not point to air intake issue
If you think that the O2 sensors are CAUSING the problem, unplug them and drive to see if there is an improvement. If the driveability problems persist with them unplugged, it would be hard to argue that erroneous O2 voltages are causing them.
I remember suggesting this before in this thread but I don't think it has been tried.
and its official it is NOT the O2's. sure hope they will take them back at parts store. only turned the truck on once lol wasnt fixed said ok.
So, im coming to the conclusion that somehow someway by putting the stock intake on i have altered the parameters of the tune. OR something has gon array with it. I cant think of anything else that could be wrong.
I wander if you have any leaks in your intake manifold.
Maybe in that spacer since you used rtv, like you said. Intake gaskets arent cheap and who wants to tear down the top half of there motor on and put it back together just to find that it still isn't fixed.
This thing is hell.
Good luck on your next attempt to fix it.
ok so you installed new o2 sensors and determined they were not the problem just from starting the truck? did you let it run for awhile? try driving it? the computer needs to relearn and adjust. you cant just throw them in and say oh i guess they didnt fix it
alright. to clear things up. I did in fact waited until it warmed up, which didnt fix the problem. Also the problem still came up the sencond i turned the truck over and it ran, therefor it cant be the o2's either. so those have been ruled out.
Damn......this sucks. Are you using the stock Maf housing? I started out trying to use an aftermarket tube and my truck still ran bad.....I had to modify the stock housing to work...but it cleared up my issues. Hmmm might even be a Bad Maf you got from Autozone..I went thru 2 new Mafs till I got a good one.
Last edited by Topdog2007; 10-26-2010 at 11:37 AM.
How about the CPU itself... is it even possible to use another computer with your setup ?
If so can you find one to try out ?
Seems funny that this is going on for so/too long, sorry about that for your sake.
Here's another idea, got some extra money... are there any shops that might tune 5.0L... maybe take for a Performance Tune Up and see if they come up with something different. It is coming to a point that you are going to need a pro in there.
You have a nice truck, pay the price and see what happens, maybe Mel can give you an early B-Day present ! LoL...
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