Problems =\
Problems =\ Ok so heres my situation, read carefully.....Ok a couple years back I got my car tuned for Heads/Cam/Headers, no cats etc...I had the Stock MAF on at that time. A year or so ago, I made the mistake to go with the SLP 85mm MAF without tune. I honestly can't remember why I did it. My car has been throwing the P0300 Multiple Misfire, the P0140 and P0160 Bank 1&2 O2Sensor 2 Inactivity, due to no O2's being there. I thought the tuner tuned them out. Recently I noticed also the P1133 and P1153 codes showing up for the O2's. I just purchased a used Stock MAF 75mm, plugged it in and codes are still there. If i get hard on it in first gear or a start the car is like a bullet.. If im crusing at like 30ish or whatever and tap the gas, or ease into it the car seems to almost "Cough" Like power, dive, power........I hope that the misfire is something to do with the O2's maybe? Im puzzled. I read online that resetting the PCM by unplugging it for a while will reset the fuel curve that car car may of learned with the SLP MAF, so hopefully tomorrow when I plug it back in and have the stock MAF the car will learn that one....... Any suggestions?
tune The car was fine after the tune while I lived in Florida.. Would the car sitting without power for a long period of time have something to do with it being out of whack? While I was stationed in Michigan the car would sit long periods of time in storage...like a few months without power, I think thats when it started to have its issues...New plugs, wires it didnt change anything.. I wonder if maybe my o2's are out of whack.. I don't think I replaced them ever...
A tuned computer is hard flashed meaning even without power, it still has that flash in it. So without power would not be an issue. However, it could be lots of other things wrong, which is why I suggest getting it checked by someone in person. It may just be something simple, like a bad sensor, or something chewed by an animal.
Different Plug wires.... Ok so I took out my spark plugs and wires.. the PLugs looked real good, TR6...One issue is I noticed that one wire (AC Delco) was different from the others (Packards)... I did a ohms reading of kohms..All the 7 of the same wires read .3 k-ohms. The Ac-Delco read a .8 k-omhs.. Will that throw things off? I had MSD 8.5 during the tune.. think I broke one and went back to the olds do to not having money at the time, I figured out that I only had 7 so i bought one probably the ac-delco from a auto store...
Testing the Coil Packs Well got my MSD 8.5s in the mail and one reads O.L. Have to send it back. Anyhow. I figure I might as well test the coil packs. Only issue is im not getting ohms or any continuity from the Post (spark plug attaches) to any of the pins on the actual coil, on any of the coils. There is no write-ups on how to properly test the packs.. Only thing I see is how I test to see if there is any spark at all. How do I get strength of the spark and to know if its continuous...Im baffled.
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TECH Addict
Joined: Aug 2005
Posts: 2,305
Likes: 126
From: Monroe,NY
This may work for you.While the car is running point a temp gun at each header pipe coming off heads.If one is reading a lower temp by a good amount that will be the one with the bad coil.That is how i found mine.
Last edited by gagliano7; Feb 15, 2013 at 09:15 AM.
Uhgg Ok so i switched out the Plug wires back to the old MSD 8.5's That were on there when it got tuned, I checked the spark plugs, they look good. I changed out the Fuel Filter, cleaned the fuel injectors, all appeared to be working. Made sure the intake gaskets looked good and reseated the intake. Still getting the P0300 misfire code, actually it shows up twice on the Matco MD9000 reader...The smell of fuel hurts my head if I sit in it to long at idle... Im ready to take a Hammer to the engine and send this P.O.S to the grave yard. Could it be possible low fuel pressure? Should I go back to NGK TR55's instead of my 6's? This care ran great after my tune like 4 years ago.. After I got to michigan it ran like **** and how im back to florida finally, it still runs like garbage.
Started thinking I pulled plug wires from the coils one by one, it didnt seem to affect the idle at all, course thats with one only pulled out at a time...So I started thinking. I smell fuel, so apparently its getting it, maybe its not burning it off properly? Wonder if I should go back to the tr55's, IDK some opinions wouldn't hurt.. maybe someone else in this situation.
Temp gun results... Don't know how accurate these results are.. im using a 25$ IF Temp Gun...Ok so here they are.. CYL 8 435F, 6 352F, 4 342F, 2 256F, 7 150F, 5 470F,
3 343F, 1 310F....Like i said.. i don't know how accurate that is.. If anyone has good base numbers let me know....Also I don't know why if i pull a wire from the coil pack i really dont hear any difference in idle.....
3 343F, 1 310F....Like i said.. i don't know how accurate that is.. If anyone has good base numbers let me know....Also I don't know why if i pull a wire from the coil pack i really dont hear any difference in idle.....
Teching In
Joined: Mar 2009
Posts: 30
Likes: 0
From: Marble Hill, Georgia
One bad coil will show a misfire code on that one cylinder. You can move the coil to another cylinder to see if the misfire code moves to the new cylinder. That will prove out a bad coil. A bad fuel injector can also throw a misfire code on one cylinder as well as other things. You can test a coil with an ohm meter. I'm sure you can find a web page that explains how.
tune..etc I don't think its the tune.. it was fine after the tune and while..a year or so ago is when the problem started, about 2 years after my tune.. Unfortunatly im getting the "Random" misfire....There is not a page on how to ohm read your coil... I tried. The engine is getting fuel, the smell is strong..like its not burning it properly. Idk. Ill play with it on my day off Wednesday and see if I can find anything. Ill check the fuses for the maf.. Will the computer throw a code if that were the case?
TECH Addict
Joined: Aug 2005
Posts: 2,305
Likes: 126
From: Monroe,NY
One bad coil will show a misfire code on that one cylinder. You can move the coil to another cylinder to see if the misfire code moves to the new cylinder. That will prove out a bad coil. A bad fuel injector can also throw a misfire code on one cylinder as well as other things. You can test a coil with an ohm meter. I'm sure you can find a web page that explains how.
Cylinder 7 is your problem temp is way to low.cylinder 2 is also on the low side.