Need Help! Stalling At Lights And Flat Spots During Take Off

[D1STRB3D]

Hi People

Need Help BIG TIME....

I have a R33 GTS25T

Exhaust and Pod (aftermarket) - Everything else Standard

When I go to take off I get major flat spots, like the car is starved of fuel... no back fire just wont deliver any power and jerks and feels like the car cuts out when I give it some revs.

At the lights she'll idle fine then stalls some times.

The Problem is intermittent and I find it a major safety issue if i was crossing a main road :S

I've never thrashed it and it was running fine since I bought it till now.

it is an import I am the first Australian owner and I bought I at "86,000Ks" which it is now at "91,000"

fuel filter (which I thought would solve it) is new installed yesterday.

I thought the following will solve the issue....

Fuel filter

AFM

AAC

coil Packs

Spark Plugs

Throttle body

OXY Senor

I know it should be one of these but hoping that someone has had similar symptoms with there car and found a solution without the cost of unnecessary parts

Thanks in Advance

[koduRB25det]

most probably coil pack. check the resistance on coil pack and wiring. it is always good to clean the AFM and check the resistance as well. check your TPS voltage. [full close .4v and fully open 5v half way open 2-3 v inbetween]

Edited August 26, 2011 by koduRB25det

[DVS JEZ]

Disconnect the fast idle control motor (purple plug from memory, inlet manifold right near firewall) and see if it still happens.

[D1STRB3D]

Update I've cleaned the Ive taken the coil packs out and all of them have a scorched mark on the coil pack, would this be fair to say they're buggered??

I only thought this because I saw them on pots 2, 3, 4, 5, 6 but never saw this on pot 1....

Thoughts???

again thanks in advance.

[mad082]

try wrapping them with electrical tape and see if it alters things. if it does then you know the coils are shagged

[D1STRB3D]

Electrical tape???

I forgot to mention before that i took particular notice when I went out in the car today and noticed when the car gets to a certain temp it starts to play up and stall ect... when I pull over and let the engine cool for some time she starts back up and is fine till that temp is reached again.

Thats what made me think the coil packs have arced out or blown out the side of the coil pack, hence why when they reach a temp they play up....

Is there something I'm missing or another suggestion?? I would just hate to buy a new set of coil packs and suddenly find in the middle of an intersection, that coil packs weren't the problem plus the money factor..

:S

Thanks for the suggestions so far and again thanks in advance

[koduRB25det]

1+ MAD82. try that first. see any changes. then change the. coil packs. if i'm u.. i'm gonna change the coil packs. good luck mate

[D1STRB3D]

Not sure what 1 +MAD82 is would you be able to clarify???

Yeah looks like its the packs that'll need the change

thanks

[karma_syke]

a better solution to wrapping them in electrical tape is to coat them in silicon, i had mild coil pack issues and they disappeared after i did this, silicon is a better insulator and stands up to engine bay conditions better than electrical tape.

[TTT]

what they are saying is to tape up that section of the coil packs that have the mark.

do a couple of layers.

this will "temporarily" stop them from arcing if that is in fact what is happening.

If it fixes your issue, buy new coil packs.

if it doesn't, then you didn't waste $500

the silicon option is better than electrical tape but it involves going and buying shit from bunnings where as most people have elecrical tape around.

also, while you have the coil cover off, put all the coil packs back in and at night once up to operating temps and you feel a miss etc, in the dark, pop the bonnet and see if you can see it actually arc in the valley where the coils are.

You can see it in the dark if it is actually arcing.

[koduRB25det]

yes mate it is your coil packs.

Not sure what 1 +MAD82 is would you be able to clarify???

Yeah looks like its the packs that'll need the change

thanks

[mad082]

just occured to me that you haven't mentioned what series r33 you have. the reason i say this is that the series 1 had an external ignitor (series 2 have it built into the coils) and these often start to have issues once they come up to temperature in the same way that coils will.

so if you have a series 1 and taping up the coils (or putting silicon on them) doesn't change things then i'd try and get your hands on a replacement ignitor pack

[D1STRB3D]

Oh darn it guys sorry yeah its a series 1 and I had thought that after coming to the conclusion of all the great suggestions you guys have given I forked out for coil packs.

Darn....

MAD082 thanks for the input there, I'll see how these new packs go and let you all know. (so the s1 has the external ignitor, I had NO IDEA!! Please Explain and is this a bad thing that they are external??)

Thank again guys and thanks in advance

[Rapidflow]

check the basics first dont get all scientific. battery terminals, fuel pressure, spark plugs and timing is a good start.

coil packs wont cause it to stall and mostly break down under boost.

if u have retardted base timing on a stock rb they will hesitate and drive crap, 0 to 5 deg btdc.

if the fuel pump is on its way out (very common pump is nearly 20 years old) it will hesitate on accel and wont idle. this is due to r33 having varible earth control of the fuel pump. at idle the the voltage to the fuel pump is dropped to cut down the pump noise level thus dropping fuel pressure, and when reved it is given full power thus giving full pump pressure. So if your pump is stuffed at idle ur fuel pressure might get below 20psi which is not enough to run, starve then stall. when u rev the engine the fuel pressure will be building slowly holding back then sort of clear up and go good. 2 ways u can elimate ur fuel pump without a fuel pressure guage 1. clamp the return line giving u full pressure. 2. give the fuel pump a constant ground via the sender wiring plug in the boot.

try that see how u go

[mad082]

Oh darn it guys sorry yeah its a series 1 and I had thought that after coming to the conclusion of all the great suggestions you guys have given I forked out for coil packs.

Darn....

MAD082 thanks for the input there, I'll see how these new packs go and let you all know. (so the s1 has the external ignitor, I had NO IDEA!! Please Explain and is this a bad thing that they are external??)

Thank again guys and thanks in advance

you will see a little square unit at the back of the coil valley cover. this is the ignitor. as for pros and cons of it being external, well there are a few of each. advantages are that if it is purely an ignitor issue causing a spark issue then you don't have to replace coils, you can simply just replace the ignitor. you can also use it to setup a wasted spark system (can use different coils, such as commodore or falcon ones) if you do need to replace the coils. disadvantage is that it is something else that you have to look at when having ignition issues.

[D1STRB3D]

Ok update with all, replaced coil packs seemed to run better than fine..... until...

Flat spots once again and it happened on the freeway. I popped the hood gave the AFM a tap and she ran for a bit when i tapped it again an wiggled the plug a little she turned off.

AFM on the way, could there be any other thing that could cause this now im on a shopping spread of some nature??

[TJR32GTS-T]

Maybe change the fuel filter?

Have u tried cleaning the AFM?

Re-gap your spark plugs or replace if fouled

Is your car running a atmo BOV?

[D1STRB3D]

I get my AFM tomorrow fingers crossed it solves the problem.... hopefully....

I've Cleaned the AFM, and changed the fuel filter.

I've been driving it to work the past couple of days and it seems that it seems okish as long as you dont put her under boost....

BUT, when I 've been driving a while it seems to play up, its almost like (too much boost plays up, engine gets really warm plays up, tap AFM plays up drive it for more than half an hour or so plays up)

OH and no I dont have an atmo BOV... actually what is an atmo BOV, as far as I know the BOV I have now is standard :S

Thank Again Guys For The Input

[Samuel Leonard]

your car will start and idle with the afm unplugged. i'd try that. if you are running the engine and then pull the afm it will nearly stall for a few seconds (or maybe it will stall) and then it will pick back up and idle. you will then have the revs limited to 2500 rpm though but if it still stals and runs crap with the afm unplugged i'd assume the afm isn't the problem. the engine just assumes the air flow at idle and won't let you boost (hence 2500 rpm limiter)

[SargeRX8]

Could be a vacuum leak. My car is doing something very similar and strange. Until it is warmed up its fine. Once its warmed, it lean pops a little and stalls when clutching in after boost. But it drives perfectly fine apart from that.

Check all the little thin black hoses are plugged in nicely and don't look all dry and cracked.