scooby87

iTrader: (5)

Lately (last week or so) when starting the car has really been struggling to turn over, a quick tap of throttle and it would then idle normally.

Last few days it now dies on first start up no matter what i do.


This only happens on the first cold start up on each day, once the car has been started this problem goes away :S


Does this sound like its being starved of fuel?


The only change in my car is the addition of a pp chipped ecu, but i'm sure the ecu was fitted a fair few days or maybe even a week before this started happening?

Glowplug

iTrader: (8)

What plugs are you running, still standard 6's?? They will be getting a bit hot with the PP chip fitted. Just a thought.

scooby87

iTrader: (5)

yes still the standard plugs as far as i know?

I assume they have been changed at some point for the service? it has full dealer servicing up to current mileage before i bought the car.


**Something i forgot to mention was it started being lumpy when i was driving this evening... again it felt like it was starved of fuel or something.. when i gave it some throttle it stopped doing it...and then it was fine again.... ??

Glowplug

iTrader: (8)

In that case i would remove and check the plugs then replace the standard PFR6B's with a set of PFR7B's and gap them to 0.65mm. These colder plugs are recommended for modded cars as the 6's get too hot and will degrade causing running issues.

I assume you have a decat exhaust and a high flow air filter too.

scooby87

iTrader: (5)

You assume right

Will get some new plugs then and post back with the result, I will stop driving the scoob untill I get that sorted. I'm guessing it can't be good for the car.

Glowplug

iTrader: (8)

In which case the 7's are highly recommended.

Yeah, can't be good for her. Let us know how you get on mate. *thumbs up smilie*

Smilies not workin :-( lol

mit

iTrader: (10)

6's will be fine in your car, as it's not running huge power. 6's tend to give misfire problems when running high boost, not so much at idle.
I'd put my money on your ecu water temp sensor, it tells the ecu the temp of your car, and fuels to suite. If it's faulty, then you'll get idle problems when cold.
I just this weekend changed mine for the same reason, it's now perfect!

Glowplug

iTrader: (8)

Your not running 'huge' power mit, 334bhp, yet you have 7's fitted.

My diagnosis is based on the fact that the OP has recently fitted a PP chip and the problem has started soon after, the car will be running more boost/fuel/heat, if the standard plugs are not in tip top condition then this will cause starting problems, and after all 7's are recommended for other than standard engines as you are aware. Surely if it's the water temp sensor the OP would have starting issues through the tempreture range and not just at cold.


Does this sound like water temp sensor too?? Sounds more like bad/weak spark to me, just MHO.

scooby87

iTrader: (5)

Thanks for some more replies there guys, i was going to get the plugs today but realised i'm a tad broke so might be a while before i post up the result....


Sooner rather than later i'm sure though as i hate driving the work car!

mit

iTrader: (10)

I'm not saying 7's won't work, i'm saying the 6's will be fine, in fact i'm sure they are standard fit on sti's, which run more power.
No, i'm not running huge power, i used to have a pp chip, with 6's, before i started to get a bit more serious, now i'm 100bhp/100ftlb up on standard(as opposed the pp's 30/30), and as i was getting a misfire at high boost/revs(1.5 bar), i needed to re gap the plugs like you say, although i went for .6mm gap, it made sense to fit 7's.
Your comment sounded like 6's were to blame, purely cos they are 6's. Granted, if they are in poor nick, they won't be great.
Also, you don't tend to get starting/idle problems with the temp sensor when it's warm, it's the cold starts/idle that are the problem, as the car thinks it always warm.
But, this is just my opinion

scooby87

iTrader: (5)

Interesting...... i might try and start the car tomorrow from cold with the old ecu in and see what happens.....

scooby87

iTrader: (5)

I bought the spark plugs today, not fitted them yet though, gonna go do that now.

Am wondering though how do i gap the plugs to 0.65mm like you said, i have nothing to measure that distance with besides a ruler lol.

Glowplug

iTrader: (8)

You need a gapping tool/feeler gauges, halfrauds or local car parts shop

scooby87

iTrader: (5)

Luckily my dad had a feeler gauge, fitted plugs, was actually quite a nice job.

Test drove and car felt really good whilst i was pottering around warmer up, much better on deceleration and very very partial throttle, felt nice and smooth.

However was still a lumpy startup, but did not stall.

Here is the problem though

Now on proper boost (1 bar ish) it hesitates big time n then i obviulsy ease off. This happens in all gears... well i didn't check 1st or 5th.

There is no hesitation untill the car starts to make proper boost when accelerating fully.



* I'm sure this is irrelevant but i did not torque up the plugs because i've never done that for plugs, they are now a tad tighter than when i removed them though as i thought they were loose when i took them out.*

*Could incorrect gapping have caused this, maybe i can't use a feeler gauge properly?*

*Only other change to the car was i moved my air filter round to where i think it will get a bit more air and adjusted its heatshielf, again i'm sure thats irrelevant?*
Any ideas guys? I can't believe its got worse now it has better plugs in???

mit

iTrader: (10)

Well, if you haven't gaped them correctly, or damaged one of the tips when adjusting them, it could cause the misfire.
As for the lumpy idle, were back to my first diagnosis, i think you were led down the wrong path.
Basically it sounds like there was nothing wrong with the plugs in the first place.
I take it the gaps were made smaller than standard? I feel the 0.65 is not enough of a gap change(standard 0.7), to really make a difference. You want 0.6-0.55 really.
Do you have the single coil pack on the inlet, or individual coil packs on each plug?

scooby87

iTrader: (5)

They were very close to 0.65 mm gap from the box anyway, so i just closed them up a tiny bit being very carful not to damage them.

Coil pack on each plug i think.

So if i reduce the gap size further tomorrow that may cure this?

mit

iTrader: (10)

They really need proper adjustment, make sure they are exactly .6mm.

scooby87

iTrader: (5)

ok, i'll do that and post results tomorrow!

Glowplug

iTrader: (8)

Also check for cracks/damage behind the rubbers on the coilpacks whilst you have them off

scooby87

iTrader: (5)

Will do

scooby87

iTrader: (5)

Good news, re gapped plugs to 0.60mm and no more missfire

But start up was crap and stalled on first start, second start was fine. General driving is good.

joz8968

iTrader: (13)

Do a ECU reset - it may have a hangover form when it was playing up with the bad misfires i.e. too rich fuelling. Do a reset to start from a clean slate, so to speak... chances are a smooth idle will return...

scooby87

iTrader: (5)

Good thinking joz

Will let you know how that works out!

scooby87

iTrader: (5)

Unfortunately the reset didn't make any difference.

So how do i change the water temp sensor?

This is starting to get on my nerves, every cold start it now stalls straight away without fail! Then when i start again revs up to 2k then slowly drops back down.

This is now everytime, no longer an intermittent problem.

julienmatthew

iTrader: (1)

how did you get on with starting your car from cold as im having the same problem with my classic. put redex in the fuel and made a difference for a couple of days but then back to problem starts.had a service changed plugs still no joy , love to know if you solved the problem ,cheers matthew

joz8968

iTrader: (13)

If your avatar is anything to go by, then cold-starting is surely a low priority at the moment?

julienmatthew

iTrader: (1)

ide just had the engine serviced and lost it on a bend and hit a concrete pillar ,thankfully i was on my own family at home so only myself hurt and my pride cheers matt

joz8968

iTrader: (13)

Sorry to hear that mate - gutting.

But important thing is that you're still here with us in good health.

scooby87

iTrader: (5)

No joy with the starting issues still.

But i don't know how to change the water temp sensor as suggested above.

When i get a minute i'm going to put the pp chip into my spare ecu and run the car from that and see what happens, i'm assuming the water temp sensor is on the ecu....

Glad your ok after your accident btw.

joz8968

iTrader: (13)

What MY is yours? It's a 1995 innit?

The coolant temp sensor (CTS) is at the rear of a metal water coolant crossover pipe. The sensor is a brown plastic & brass thing, screwed into the rear of it. It's sort of sited between the turbo and intercooler, down on top of the engine. Also, next to the CTS is a similar looking, but smaller, temp sensor unit (for the temp. gauge in the binnacle).