DanaliHD

iTrader: (5)

anyone think the MAP sensor could be the problem? it reads normal, but....

on my last log where i recorded the problem, the tps was 73%, maf was 60.47lb/min, map 103, rpm 3700, O2 and all fuel trims were 0,

then, immediately, the maf went to 0.22, then back up, then back down, back up,

truck slamed hard on it's face. almost like the engine shut right off. ouch!!

DanaliHD

iTrader: (5)

for comparison's sake, this is what my readings were when things were working.

tps 77%
map92
maf 32.64
O2 sensors 920
stft and ltft 0
4800rpm

DanaliHD

iTrader: (5)

help!!!!!!!!!! all wiring has been checked.

brad8266

iTrader: (23)

does the TPS read ok?

DanaliHD

iTrader: (5)

good question. as far as i recall. why do you ask?

brad8266

iTrader: (23)

I thought it would be a good thing to verify is working right, just hook the scanner up and run through throttle positions and verify that it is reading position as you blip through the gas pedal. You said he wased your engine bay, well water could have damaged a sensor in there, better to narrow down the possibilities.

DanaliHD

iTrader: (5)

I checked the voltage going to the Map sensor with the key on, it was 4.X. I had the truck in the shop yesterday and they did a "smoke test" to see if I had any vacuum leaks. I don't.

I'm puzzled now. I can't figure out why the maf is reading so damn high. 60+ at part throttle when it used to read 40+ at WOT.

dewmanshu

iTrader: (4)

hey danali, I don't have a solution for you , but I am curious of when you say if you go into "sd mode" it runs fine, but when in maf mode it will fall on it's face. You also mention your WB is on the fritz...where I am going with this is, your open loop table...how safe is it when you are running the maf? When the maf fails (and you don't necessarily need an ses light) the truck goes to that table right? In most tunes that I have looked at that, that table has the normal operating temp and maps at 1. That as I am sure you know is 14.68 at WOT. You'd fall on your face too running that lean. I just bring this up because chasing what seems to be a bad ground and still blowing your motor will be very disheartening (is there such a word?)

With that said...make sure the open loop table is "safe" while your trying to figure all of this out.

Back on topic...if it is a bad ground (most bad grounds are not constant), you could think the map is fine with key off and key on-idling, but as soon as you get the system to a particular voltage with the "7x% TPS" **** then goes haywire. I run an electrical contractor doing plent of troubleshooting scenarios and I gotta tell you...it's most likely NOT a coincedence this all started with your stereo guy do his "cleaning" and installation. All it takes is one wire in one spot to cause a butt load of issues. Keep us informed. Replace that map sensor for ***** and giggles. Actually....in sd mode what does the map sensor do? Is it crazy?

DanaliHD

iTrader: (5)

does the HVAC system have anything to do with the MAF sensor? The audio buy relocated my controls so he had to cut all of the wires and lengthen them.

jimmyblue

iTrader: (11)

There are notes about the MAF signal being sensitive to
EMI, in some of the code descriptions. Perhaps you want
to extract the MAF wires from the bundles they travel
in, and get them away from any audio, spark plug,
injector drive wires. Maybe wrap them with copper tape
and ground-strap it, evem, if this works out. Maybe the
wiring job has put you coupled up to something nasty
noisy.

DanaliHD

iTrader: (5)

I read today that the PCV could be causing the code or even something as simple as the dipstick not being put back in all the way. If the pcv is what i think it is (tube coming out of the valve cover), there is oil all around it and it pulls out of the valve cover very easily. seems way too loose.

Bad30th

iTrader: (13)

Snug up all the connections with nylon pullties and see if it helps ? That's what I did (because the loose connections bothered me), but I wasn't having any problems with codes.

Rob (Bad30th)