R32 Gtst Problem Child

[beemae30]

This is really frustrating. It takes 4-5 seconds to start, and once it does it farts around for 10 or so seconds idling at super low rpm such that it sounds like itll stall. I can film it if thatll help anyone. Im thinking maybe fuel pump?

[beemae30]

Maybe fuel filter? Not stopping the fuel bleeding back to tank?

[beemae30]

Cleaned the aac and iac. Aac was pretty choked but the iac was fine. Also found the battery voltage was dropping to 9 when starting could be causing the issue i think? Not supplying enough voltage to the fuel pump at idle when the variable fuel pump setting is at zero. Anyone have any ideas?

[DVS JEZ]

Does it start fine with some throttle?

[beemae30]

Nope starts and farts around till it sorts itself out. Sometimes it will start and if i pump the throttle it will rev up and settle normally. Are you thinking tps? i have checked it and it has 0.000 ohms at idle and goes to OL between idle and full load and i cant remember the WOT resistence.

[DVS JEZ]

U need to check tps voltage not resistance. Set closed throttle to around .45V and check that it smoothly rises all the way to WOT.

I was asking about the throttle too see if it needed throttle ie more air to keep running. But as it doesnt it sounds like it may be too lean on start up.

Try crimping the fuel return line when starting to see if it helps. U may need a new fuel pressure reg

[beemae30]

Alright, I might check that. Yeah i don't think its the tps. It only happens when its stone dead cold.

[DVS JEZ]

The battery voltage is a possibility too as u asked. Ecu jas a voltage correction map which affects injector opening/lag times. Try using jumper leads or another bigger battery to see if it helps

[beemae30]

Alright so this morning i tried what you said and found it will still crank for a little bit before it starts but it definetly doesnt do the rough patch for as long. And yeah im thinking the problem is compounded as from what ive researched the r32's have a variable pump controller and at idle they see about 3v's less then at throttle. So im thinking if my main volts are dropping to 9v at start up then fuel pump will be seeing around 7ish and therefore the flow rate will be down as well. Just for information battery is some bucket of crap 270cca supercheap auto non sealed jobby.

[DVS JEZ]

Any progress on ur issue

[beemae30]

Nope not as yet i have found moving the throttle off the idle position definetly makes it start quicker so i am thinking it is a battery/ fuel pump voltage issue. What do you think? Also i have noticed that the boost seems to come on hard from time to time. I know the bov is dodge as, i've had to strip it and relinish/lube it to stop it from seizing do you think this is the problem or could it be a fuel surge issue leading back to maybe a fpr?

[AngryRB]

Nope not as yet i have found moving the throttle off the idle position definetly makes it start quicker so i am thinking it is a battery/ fuel pump voltage issue. What do you think? Also i have noticed that the boost seems to come on hard from time to time. I know the bov is dodge as, i've had to strip it and relinish/lube it to stop it from seizing do you think this is the problem or could it be a fuel surge issue leading back to maybe a fpr?

Hey im not sure if this helps but ive had some issues with my battery also, which i plan on replacing, seems that it will start on 13volts but takes longer, so cranking without starting would flood the engine wouldnt it and lead to rough idle for a few seconds.

and if the blow off valve is leaking then that will definitely result in cutting in and out cause of the fuel mixture and make your idle rough...

[beemae30]

Well not really, if it is cranking and your voltage stays above 11 it means your battery is pretty good and that your problem is ignition related. Which then means you are flooding the engine because the injectors are firing fuel but the coils/spark plugs arent igniting it and so each revolution it slowly saturates the air a little more till it fires. And i think the bov is only leaking at idle and once boost greater then the vacuum pressure from the engine the piston seats and the pressure ring excites sealing it. I think the bov is just crap its a go fast bits plumb back.

[beemae30]

Alright clamped the return line this morning and it definetly started quicker but it still was lumpy for a little bit but shorter duration. So quiet possibly fpr? i can also smell fuel in the engine bay lightly from time to time. I am thinking that this is to do with my removal of the catch can more then a leak as i have replaced some of the fuel line that looked dodgy already. And im also getting pretty normal fuel economy (450 to a tank city)

[beemae30]

Edited June 21, 2011 by beemae30

[AngryRB]

Hey does that oil guage work properly cause my rb25 goes up to and stays at like 6 for the first few minutes... just a thought

I think its the TPS like DVS JEV said, had a similar problem in a commodore, replaced battery wiring, lead plugs etc, turnt out to be the TPS....

that would also explain the boosting problem.

Edited June 22, 2011 by SliverS2

[beemae30]

Yeah it does it goes up to 4 bar at cold and stays there till the oil is hot then drops down to about 2 at idle then goes to 4 above about 2000rpm. They do have a tendency to play up a bit so ive heard. And i dont think its a tps its a strange issue to be tps related. Plus ive checked it with a multimeter and its ok. It's a fuel issue i think as it's only when its dead cold. As soon as it's started once its fine then it takes about 7 hrs to start it again.

[beemae30]

Any help dvs? I jumped it this morning and it didnt help so that eliminates the battery problem. So thinking fpr or fuel pump?

[beemae30]

Oh an dvs. My TPS has 0.3v at idle and goes straight to battery voltage above that. So that sounds about right. Once ive started it the first time it idles fine aorund 900 rpm. I've just noticed as well, my IAC line to tb has a crack around were the clamp is and also i can smell fuel around cyl 6 and im thinking the top seal is leaking.So tomorrow im going to prime the fuel pump a couple of times and see if that helps the issue.

Edited June 24, 2011 by beemae30

[beemae30]

I pulled the aac and iac apart again today and i tested the IAC and it doesn't move when 12v is applied. So pretty sure that is the issue. Anyone agree?