spuddering, wont rev and missing, help?
 

okay so driving home today from work I had the car idle up to operating temp before leaving

and on the way back it was just puttering and it was like the 3800 hesitation but way worse.

problems:


wont rev past about 4k and barly revs to to 3k under more throttle

it does it in gear and in neutral. I DO think its the primary coil, could I be wrong?


recently the car has just gotten an SAFCII install (which works fine) and an oil/filter change of 20w 50

I got only 50 miles left on the 500 mile break in of the aluminum flywheel so I havent driven past 4k, well maybe gone for 4500-4800ish a few times, but VERY few.

motor go kablewy?

no actually.


oddly enough i checked the MAP sensor and the throttle position sensor and sat around for 20 minutes, started it up again and it was fine, and both sensors were working correctly.

and its been like that all day.


but it was after I put in the code checker and got nothing.

fidelity you might want to check to see if fuel pump is going out i got my rx7 and when i drove it for a few seconds it would not want to go 2 to 3 thousand rpms it would cut and lag out and sputter really bad and it finally turned out to be fuel pump hope this helps. :Kill1:

Check the O2 sensor. Mine had the same symptoms and my plug had just come loose. Easy fix.

its got a new walbro255 put in maybe a year ago

and the 02 sensor looks new.

just looked at it when I did my header install a few weeks ago.

ive driven it yesteday in the heat and it didnt do it again and it drove fine.

and im driving it today soon again.

I'm not saying the 02 sensor would be bad, I'm talking about the plug that's on the wire that plugs into the main harness. Just follow the wire (the one coming out of the sensor) away from it and check that the plug is connected.

if the 02 sensor wasnt working id be running so rich id be shooting huge flames.

Just saying I had the same symptoms, plugged the wire back in and it solved it.

well it didnt do it all of today and it was hotter than friday. no issue. it was fast as hell the break in was done :D

Yesterday on the way home, mine did the exact same thing.

I pulled into a dairy queen to grab a drink for the 120 mile drive home, and stalled the bitch by accident. (Read as, six puck clutch is a pain in me arse, still breaking it in?)

Tried to leave the dairy queen, and any time I opened up the throttle, it would spit and sputter and do nothing. A very light touch on the throttle and I was able to keep going.

I got pissed off and pulled over (car was idleing perfect though) and turned it off. Played with a few things, started car up. It died after 4 secs. Tried again, same result.

Thankfully, I at least knew how to fix that problem! Sure enough, the MAF was coming unplugged (lost my clip somewhere). Plugging it all the way back in not only cured my 4 sec problem, but it also ended up being the cause of the sputtering. The plug was partially undone, and that's what caused my sputtering.

Check to see if any error codes are present. Could give you a place to start.

I would check your AFM........pretty much garuntee you its fubard.

will it rev up decent (dry rev, sitting in neutral) with only 2% throttle?

more than likely the AFM went for a shit.

Mine does this too... sputters between 1.5-2k. The more gas I give, the more it sputters. When its sputtering, I hear a kind of whirring sound as well, which sounds kinda like a fuel pump. Funniest thing is though, if I can get it up above 2.5k, the throttle will catch and the car acts normal... till I let the rpms drop below the 2k mark.

No codes... I've checked the O2 sensor as suggested, it was brand new when I dropped the engine and is still connected. Checked the AFM connection, also good. I'm thinking it might be the fuel pump now, as my fuel gauge never tops off... I figured the floater was gunky and got a new pump, just haven't had time to put it in.

Another thing i've thought of is the throttle body... I had one that worked, but when I swapped my engine, I found another one that looked nicer, so I used it. The BAC was bad on it (which I just fixed) and I suspect the TPS might also be bad. But, when it starts having sputter attacks, I pull over and, with a flathead, pry the throttle up ever so slightly. That has fixed it the last 4 times i've experienced the problem. Maybe something is keeping the throttle from returning to idle? I don;t know why this would affect it though, as it should just rev a little higher and not sputter like it does...