Noodlebut

This first started a few days ago, i felt that while i was just cruising with my foot very lightly on the gas it would start kinda jerking... if i put my foot down or took my foot off it would stop.

I thought nothing of it... then just a couple days ago... my Rev Tacho just went out. I turned the car off and back on.. and it came back... for a while.. then it just turns off again.. .all my other gauges work, but not the rev gauge. Turn the car off then back on and it will come back.

Now tonight as i was driving it... its gotten alot worse... the car is hesitating alot. in between the 2000 and 4000rpm mark its like sometimes boost will kick in late, or so it feels, most of the time the boost will be there (according to boost gauge) and i can hear the turbo spooling... but the car dosnt go?? its like its lost a hell of alot of power... i can hear the turbo alot more now.. .that would be because the engine dosnt seem to be reving as hard... exhaust sound is much lower now...

could this be something like a Injector thats failing? or could it be a sensor failing?

any help appreciated....

Falcoms

That sounds like a bad leading coil pack, since it is connected to the tach and (don't quote me on this, I own and N/A) the turbo is being affected during this time (2000-4000rpm) because of the incomplete burning of fuel from lack of spark. Once above 4k you are running fast enough that the trailing plug is doing enough for you, so you stop having the problem. IMO I would look at the coil pack(s) and see what is wrong there

Josepi

Trailing coil supplies the tach signal.

Rookie84

Mine was doing that. Mine was just running too lean in mid-range RPM. Adding some more fuel with Microtech fixed it for me...

Noodlebut

So what do you guys recommend i do?

change the spark plugs? ... and how should i test the coil packs?

vaughnc

Hook up timing light to each spark plug. If the light doesn't work on 1 coil....

Also the FSM (factory service manual) is your friend. Download it from www.teamfc3s.org

Noodlebut

yep, i've got the manual... ive checked the resistance of the coils...

for the trailing side i got 0.8ohms for one side and 0.7ohms for the other
the leading side had 0.5ohms...

the manual says anything under 1ohm is ok... so i guess they are ok?

hmm.. could it be a vacuum leak then?...
i've tried listening for a vacuum leak... but honestly i cannot hear air leaking...

RX7.0

I had jumpy gauges(plural) and a miss too.
Hyper ground kit fixed it for me.

Noodlebut

well i noticed today that it only starts hesitating/lacking power after the tacho goes out... before the tacho goes and im driving it still boosts fine and goes hard just like normal.. when the tacho goes out.. then it starts having these problems...

also noticed after the tacho went out... when i stomped on the gas... i was looking at the boost gauge.. and saw that it was going up past the half way mark on the boost gauge and then the boost actually kicked in... normally it kinda kicks in as soon as it starts spooling...

The Spyder

iTrader: (8)

Check your firewall to tranny ground, (left hand side of the engine ba- all the way against the firewall, 1/4 the way off center- black wire with tab going to tranny)-
My friends came loose and was having these problems.
Also he had a vacume leak- the intake connector on the turbo finaly cracked.

Noodlebut

ok well ill check this out tomorrow when i put in the new spark plugs i just bought...