93 eagle talon 2.0 non-turbo BUCKING issues

[wiscoDSMer]

So a few months ago I was driving down the road and accelerated up to speed and when I went to let off the throttle to sustain speed she started bucking so I punched the clutch in and rev a bit and then go back into gear and all is well for a little while longer but then it started doing it again, well it stopped all together for a while and I'm busy lately so i put it on my to do list. As of the last week or so it's been doing it allot and not stopping along with misfires that you can hear during idle down and holding rpms in neutral. I don't believe i have any vacuum leaks and the spark plugs are new as are the wires, i usually run 93octane and I put a cool air intake on it that I fabricated to work with the MAF and that caused idle surging that usually calms down when the car hit op temp. I'm looking for ideas on where to start on the diagnosis that would be stuff I can do at home with my ohm meter. I figure I'll replace fuel filter and check plugs again. Then I figure to check coil pack, cas, and temp sensor, also the tps. I need tips and specs from anybody your help will be much appreciated thank you DSMtuners

 

[Spoolin92GSX]

In regard to the DIY intake, what did you do with the vacuum lines that run to/from it? Reconnect to new intake, remove and cap, etc.. 99% of my experience, idle surge on a n/t is from a vacuum leak- if it was me I would put the stock intake back on to eliminate that possibility, since you said the new one caused an issue.

 

[wiscoDSMer]

Yes I reconnected the hose from the valve cover but surely I will be reverting to the stock set-up to eliminate that possibility thanks for the suggestion!

 

[Spoolin92GSX]

No problem, you'd be amazed how many times little things like that get overlooked. I would also make sure the TPS is adjusted and working properly, and testing the MAF can't hurt either.

 

[WES_393]

I don't believe i have any vacuum leaks...

I put a cool air intake on it that I fabricated to work with the MAF and that caused idle surging...

I wouldn't assume you don't have any vacuum leaks, especially since you recently installed an intake and developed idle issues. Since the MAF is a major part of controlling fuel delivery, any air that slips past it will throw off the ECU and often cause running issues. So it would be best to make absolutely sure that the intake is free of leaks including the throttle body, intake manifold, and everything in between. Only then can you accurately check/adjust things like timing and idle speed.

 

[wiscoDSMer]

All the information you guys have given will be very useful, I put stock setup for intake back on and so far no bucking I still have the idle surge issue though and it's a little faster on the cycles then with the custom intake. I found some great tech tips but am still open to ideas before I rebuild my intake and do a polish. I've located all the sensors and noticed the wire connections are crap so I think I'll start with re-wiring those connections and test sensors. I noticed that who ever replaced the CAS last did a bad job of sealing the gasket cus it leaks oil a tad, would this effect anything other then a small mess on my tranny?

 

[tjohn23]

I had an n/t for 3 years with an idle surge tried everything.

replaced caps in ecu
isc motor

I can't remember what else but long strong short made a FIAV bypass plate out of a piece of cheap aluminum looped the coolant lines and haven't had an idle surge problem since...

You can buy one them on ebay for 15 dollars.
(i plan to do this soon so i don't have to worry about it)

oh I also had a bucking problem ended up being the fuel filter being clogged from rust in the tank.

 

[jimbob_843]

The fiav blockoff also cured my idle surge in my nt. I used a pepsi can to make mine.

 

[tjohn23]

i would try something cheap like a soda can at first, and if it works invest 15-20 dollars in a bypass plate

 

[wiscoDSMer]

I will most definitely give it a shot! I had planned on doing the bypass when I first heard about it but didn't realize how easy it is to do at home.