Possible Fix for rich, missing, and generally poor running engine.

[shifty01]

ok this is a little tsb by me for if your dsm is having the fallowing symptoms:

1. pig rich, pouring black smoke
2. under power
3. the higher the boost the worse it runs, even missing and stuttering
4. worse when cold but still bad when warm
5. a bit better when the mas is unplugged (dont ask why i dont know)
6. idles fine
7. no boost leaks
8. etc...

Possible problem: Built up carbon in combustion chamber
OR: Octane of gas too low

Diagnosis: next fill up of PREMIUM fuel and add 1 or 2 bottles of octane boost of your choice, if engine is better with the octane boost then you probably have carbon built up in the chamber, heres a explanation:

When the engine detects detonation it both pulls the timing and adds fuel in an attempt to save itself. it might do it just a little so you dont notice or a lot like my friends was. the problem is when engines run rich they create even more carbon, more carbon equals higher compression and possible hot spots, that equals detonation and the vicious cycle starts over. so this is also something that gradually gets worse and worse, it also might get slowly better, but the point is this is not a on/off thing, it cant be "my engine was running perfect yesterday and now it runs like crap" it could go from good to crap in a matter of days though.

Possible fixes:

1. in my friends case, fill up with premium not regular but it still misses under high boost so it probably has carbon built from from running rich for about a month.

2. add octane boost with every fill up

3. clean combustion chamber, ive seen people talk about mopar combustion chamber foaming stuff, ive never used it but im sure it works. other wise it would involve removing the head and cleaning it the old fastion way.


we were trying to fix this damn car for about 2 months just to find out it needed premium, were hoping it will clean itself out with premium and a bottle of fuel system cleaner but who knows.

edit: i also accept donations if anyone wants to thank me

 

[EvilAWD]

let me ask you something ive been experiencing that lately. ive had some trouble with my car overheating so i was trying new things every nite. anyway just yesterday i was driving it hoping it wouldnt heat up and once i hit about 10 pounds of boost. it began to stutter and then puff. out of my exhaust was a cloud of black smoke. what my friend told me when he was in back was that fire came out of my exhaust. i didnt think it was a big deal because my o2 housing isn't connected to my dp properly. so i figured it was a exhaust leak. no big deal. anyway could this also be the cause of carbon build up. at this point it idles fine and drives fine. only when i decide to go anything past maybe 8 psi it begins to stutter as if it had fuel cut. oh another thing i should mention is it smells like gas so maybe its not burning all the fuel? not sure any feedback would be insightful thanks!

 

[huafist]

The standard problem that causes these symptoms is known as a "boost leak".

 

[shifty01]

evilawd- like everyone on this place says, it could be a boost leak. since it did it all the sudden like you said it might be a leak, a hose blew off or something. the smell of gas would be the unburned gas, its what being excessively rich does (assuming you dont have a fuel leak). carbon could do it, but probably not that suddenly, but im sure it wouldn't hurt to throw in a bottle of octane boost next fillup and see what happens. but check for boost leaks also. also for some reason your knock sensor could have picked up a random knock from the engine, assumed it was detonation and richened the mixture.

hua- thanks for mentioning that, i forgot to say we checked for boost leaks a few times and found none.

id like you add to everyone that i am in no way a expert on dsms, i drive a 01 mustang, although i have taken 2 semesters in automotive technology so i do know a fair amount, unfortunately we barely covered turbocharged engines. we literally had a kid ask "when will we be talking about belt driven turbochargers" and when were were discussing superchargers he asked in all seriousness "when will we talk about exhaust driven superchargers", yes we all laughed at him, including the instructor, so we have to keep it simple enough for the retards(at least i have all A's and made the deans list plus got a $1300 scholarship, all because I'm what i call average). but ill try and help the best i can if anyones got any questions.