etoomey3

SO........I went home after work today, and I swapped my converter out for a converter off of a tC that a guy I know had laying around cause he put a header on his car. I installed it......and it still runs like POOP. and I'm STILL getting crappy gas mileage, I don't smell fuel anywhere...........when I took the stock header off I looked in through the ports on the exhaust side of the head and all of the valves look decent, I cranked the motor over by hand a couple of revolutions and didn't see any valves sticking or staying open......I'm almost at a dead end here......

N0AuTHoRiTy

iTrader: (3)

Not really. You haven't done a smoke test yet, have you? If you have a smoke machine, connect it through the brake booster hose and see where from the engine it might be smoking out from. Possibly a gasket went bad, either from the throttle body or intake manifold.

etoomey3

I don't have a smoke machine, but I'll see if I can maybe rent one, you think Advance or Auto Zone rents them? that's one of the major problems is I don't have some of the diagnostic tools I need, I'll try and get one

N0AuTHoRiTy

iTrader: (3)

Yea, it would be great if you could get your hands on a smoke machine which would be a more effective method to detect vacuum leaks in places that are difficult to see , which might be your problem. Get your hands on one and see if there's smoke coming out of a hose, fitting, connection, manifold gasket OR a crack in the manifold. If only you were in the NY area, I'd help you out with this. I'll be watching this post to see what the diagnosis is. Hope for the best.

etoomey3

I appreciate the input man and the offer for help, I'll try and get my hands on a smoke machine ASAP

N0AuTHoRiTy

iTrader: (3)

No problem. I also forgot to add that a weak fuel pump or a faulty fuel pressure regulator can and may also cause a misfire. So, you've got a couple of more options out there....

raptorsp123

Similarly enough I have been having the same issue. I am turbocharged, and have an Wideband Gauge, therefore I can monitor the fuel concerns. My car is rough at idle, and only at idle. I can clearly hear a leak from the engine bay, however cannot find it. I did every test possible, to the point where I began testing individual vacuum lines. Its embarrassing since I am running super lean, and my car dies when sometimes coming to a stop. I sprayed some carb cleaner last night, and found that it was ingested into the engine through the intake manifold. Did some more testing, and found out that my intake manifold gasket went sour, and air was being sucked in through there causing my misfire codes occasionally. Swapping it out tomorrow hopefully!

Check that for sure, and it may just be the case. GL