It developed gradually over several months. It all started with a run at the track when I cracked my rear motor mount. The idle is up and down between 6 and 450 at its worst. Then when cold (begining of day) it would buck in first fairly bad.

Then it started bucking when I would let of the gas while in gear from 3500 rpm down. Now it has gotten worse in the past week or so. The performance has slowly been fading but is now obviously not just the heat of summer.

I can hear a faint whine like something is leaking or cloged up or not breathing ... Checked code, left bank running lean when I leave it to act dumb and idle by itself. I actually had the idle fixed by cleaning the iacv ( i think that is what it was) and just adjusting the idle with the screw on the throttle then today I pulled the maf plug and it went back to its ways. I know this isn't major compared to others but damn this, it's really sh@ty to drive like this. ( and im hating my clutchnet with the fiber carbon pro disc!) Need 6 puck!!

I am about to throw in the towle and take it to a place I get wheels aligned and such. It is a full shop. Maybe it is the tps ? I don't know. sorry for the novel....

 

Jerks when coasting in gear
rpm's go up when push in clutch to take out of gear
seems (is) sluggish

anyone?

 

Mine bucks slightly in 2nd gear but has ever since v-2 install.

-make sure your bov is tight-not blowing off at idle (tighten to where no air comes out then a little more)
-check all your vacuum lines be very thurough!!!!! really look and touch them
-check the intake temp sensor that there is no leak around it (it is the little one after the maf- alsocheck the wires for looseness in the connector)
-check your intake manifold for anyleaks at the throttle body, and at the lower to upper manifold gasket.


Sounds like you have a boost leak, or your fuel pump is shot? Are you still on your stock pump? with inline pump? if so let me know and I'll give the exact holley part number pump you need (it is not the same one most on here run but it has worked great for me no regulator and all that crap it is a straight swap out and pumps 255lph and isn't high psi-hence no regulator swap and it still works great with the vortech FMU with no lean conditions up to 3.33 pulley although I did run a 2.62 for awhile with the 240cc injectors and it still worked alright up to fuel psi's upto 90psi.)

 

Well, I have tripple checked all of that. I see 10 psi when it is 90 degrees outside so I know its not a boost leak. It actually idle better when I take the temp sensor out! Im getting a code that reads Left bank running lean.

Left bank running lean. Could that mean an O2 sensor is out. I sure as hell hope so.

 

It could very well be an 02 sensor, As my down stream sensor has taken a shiot! and when my check engine light pops the idle bops around until I clear the code then its good,although I am planning on getting a simulator for it so i can run race gas. with no cat and no codes!

Is your t/b gasket new or reused? Also what about the EGT gasket? Are you running a catch can/pvc back to intake or no pvc return? Just ideas I'm brainstorming?

 

t/b gasket is the original, I have never taking the throttle body off. No catch can either. I have a 3.5 inch intake made from exhaust pipe. I have not changed anything so something must be broke/loose/ or dirty. I guess I need to get it hooked up to a machine and see whats up.

 

o2 lean might also be because one of the pumps crapped out on you. have you pulled the plugs? if they are white, its lean and something funky is going on.

 

good point. I just got 2 codes

0100 maf circuit
0171 system too lean (bank 1)

I pulled these codes using a chip called "car chip"

I will have to check the plugs tomorrow. But I have changed my plugs before with this idle issue with no change. It's just more recent the drivability has gone down quickly.
Sometimes this car makes me want to sale it, it's like crack! I keep going back for more..

 

Dude:

I'll sell you my code scnner for 125.00 bucks. It is an Actron. I think you rprblem lays with your maf ----100% I had the same idle issues like you with my 90 DSM it was the maf. problem solved!

 

it might be. that could cause the signal too. why would the maf fail now? is there something that you changed?

 

I actually traded someone my maf for theirs. I had put a crack in mine while tightening the bolts. This maf was from a 98 with about a 100k and n/a. Maybe it was to old to start taking boost or just had reached its time. Know of a good place to buy a new maf? thanks .

I wonder if spraying alot of that cleaner/conditioner stuff on my air filter may have an effect? I have not cleaned my filter since feb. I did take the maf out about a month ago and clean with rubbing alcohol, this was after the problems began

 

Could this be a coil pack issue?

 

Left bank lean is a pretty common issue with S/Cs on FMUs.

I know I got it every now and then - but the Dyno showed I wasn't lean at all.

Until I got the JWT ECU and 370's - hasn't come back.

 

It is bucking really hard now in all the gears. I don't know what it is?? I just scheduled and appointment with the "DEALER" to get a diagnostics test done for $75. I figure it's worth it instead of guessing and going without the maxima which hasn't been right since I broke the trans ( 3rd gear).

Hey Ian, I got the wrong disc for my clutchnet! Damn, I thought the carbon fiber pro was a step down from the 6 puck but I was wrong.

 

had the same problem...it was the PCV valve. $4 and 5 minute fix.

not sure if you have checked that out brandon...but if you havent give it a whirl.

--Paul

 

changed that before the bucking issue began. I will try it again. Now after car has sat for a few hours when I start it, it stalls out then starts right up on second attempt. Sometimes rpm's will raise to 2k and settle down slowly? When I shift gears rpm's don't fall down nearly as fast as they should? On a side note clutchnet agreed to send me a new clutch with a 6 puck( no charge)!

 

nobody has a solution, im looking for anything here. Its boost weather!

 

UPDATE! changed the intake manifold gasket and the idle issue is gone. Was missing a good portion of the gasket ?(good size piece and cracked in a few places) Clutch slips and does not hold any power. Damn I need a beater!