Fordmods Logo

Poor running after cold start getting worse, need advice. 

 

Page 2 of 3 [ 42 posts ] Go to page Previous  1, 2, 3  Next

 
Posted: Tue Dec 19, 2006 10:53 pm 
Getting Side Ways
Offline
User avatar

Age: 32

Posts: 4146

Joined: 7th Dec 2004

Gallery: 6 images

Ride: E39 523i / EF Fairmont

Location: Brisbane
QLD, Australia

Hmmm, read the techincal document, was kind of hard to follow. Especially seeing as the picture of the plug with the pins to connect to not working, lol.

How much is a map sensor, and where is it?

My idle can be a little rough, but that's generally when it's cold, and I'm pretty sure that's normal. But from time to time it can get rough while warm too.

 

_________________

E39 523i
EF Fairmont

Top
 Profile  
 
 
Posted: Tue Dec 19, 2006 10:55 pm 
Technical Contributor
Offline
User avatar

Age: 32

Posts: 2517

Joined: 7th Nov 2004

Gallery: 4 images

Ride: LS3 VF

Location: Bunbury
WA, Australia

things i'd be looking at are

1. Code Test - always the first place to start

2. Map sensor

3. Coolant temp sensors

4. fuel pressures.

5. Injectors
Top
 Profile  
 
 
Posted: Wed Dec 20, 2006 9:13 am 
Getting Side Ways
Offline
User avatar

Age: 36

Posts: 8655

Joined: 5th Nov 2004

Gallery: 37 images

Ride: V8 EF Futura

Location: Adelaide CBD
SA, Australia

EBGizmo wrote:
I have the same problem with my EF as you do - and I mentioned it last time you did :P

My amizing advice is take it to a mechanic, pay lots of $$$$, get him to fix it - then tell me what he did :P

I've had no luck finding the problem either - but one clue is that it doesn't do it on LPG! So you can rule out stuff like timing, coil etc.

Like yours, its very much temperature related, but you could also look at it as being time related - if the engine is let sit for ages, it gets cold, and perhaps the fuel pressure regulator slowly releases the stored fuel pressure? Not likely unless your fuel pump struggles as well, because that wuold prime up again almost instantly after starting, and you don't have a problem idling do you?

I am still leaning towards the intake air temp sensor, as I replaced the coolant temp sensor just recently to try and fix this - its still the same.

TPS - not likely as you would more than likely see the problem all the time.

MAP sensor - possible, but i don't think likely. (Do a "goose" test in diagnostic mode and see what pops up)

Maybe snap0964 can advise on my next suggestion: The ECU has routines for all running temps. Cold start, warm up, warmed up, WOT etc. I was thinking of doing the following as a test procedure only. Maybe you could unplug the Coolant temp sensor, replace it with a resistor of a value that tells the ECU that its going to be a cold start, then drive the car for a bit.

If you see that the problem seems to remain for as long as you have the resistor plugged in, it might indicate that the problem is to do with the fuel metering in the "cold start" routine.

If, on the other hand, the problem is there, and disappears after the normal warm up time, you might be looking towards another component that is faulty when cold, and seems to come good once it reaches operating temp.

What I might do when I have some free time next, is do this in the opposite manner - I'll work out what the coolant temp sensor resistance should be at normal operating temp, and i'll put in a temporary resistor and start the engine from cold. My guess is the engine won't hesitate at all, if its a learned cold start routine that is faulty. When I say faulty, I don't mean the ECU, just the data that the ECU may have been learning and accepting as gospel every time its cold. I don't even know if the ECU learns when its cold - thats something someone else on here may be able to help out with.

I'll try this with the Temp sensor, then the Intake air temp sensor, and go from there. I'm as stumped as you are, but it can't bee too serious, as my LPG runs 100%


^^ this is a great post!! In order to diagnose an EFI system... one must think like an EFI system....

Regarding the ECU's learning capabilities under cold start conditions....

My understanding is that the ECU is 'learning' any time that its in a closed loop state. When you first start the engine, the ECU is in open loop for a predetermined amount of time (30 sec to 60sec IIRC) whilst it waits for the oxygen sensor to reach operating temperature (funnily enough... this takes about a minute).

The cold start component of the map is really just enrichment values... it takes the fuelling value at the given load point and enchirchens it a certain %, depending on the value being returned by the coolant temp sensor... i.e. colder the coolant, higher the fuel enrichment.

 

_________________

I promise..... I will never die.

Fordmods Administration Group MINOR PUNKED

Top
 Profile  
 
 
Posted: Sun Dec 31, 2006 3:23 pm 
Fordmods Newbie
Offline

Posts: 7

Joined: 31st Jul 2006

Ride: EF Falcon

Location: Newcastle
NSW, Australia

I had exactly the same problem recently. Replacing the plugs and leads did nothing. A tube had come off the MAP sensor, and that helped a bit. I cleaned the ISC (real easy - 2 bolts and a tin of carby spray) and replaced the fuel filter, and happy days...both fuel and LPG working sensationally in my 314,000k workhorse...
Top
 Profile  
 
 
Posted: Sun Dec 31, 2006 5:54 pm 
Getting Side Ways
Offline
User avatar

Age: 32

Posts: 4146

Joined: 7th Dec 2004

Gallery: 6 images

Ride: E39 523i / EF Fairmont

Location: Brisbane
QLD, Australia

All I've done so far is replaced the fuel filter. Should I clean the injectors next, or replace the MAP sensor? I have no idea where the MAP sensor is.

 

_________________

E39 523i
EF Fairmont

Top
 Profile  
 
 
Posted: Sun Dec 31, 2006 5:58 pm 
Technical Contributor
Offline
User avatar

Posts: 691

Joined: 1st Jun 2005

Ride: EFII Sedan

Location: Brisbane
QLD, Australia

The map sensor is on the firewall near the fuel pressure regulator. Little black box with an electrical plug and vacuum hose plugged into. Hope you have borrowed a MAP sensor just to test, and aren't just spending $$$ playing "swaptronics"

Swapping parts to test is fine if its quick and easy and costs you very little, but if you have to replace the whole car before fixing it, it might be worth doing the Ultratune diagnostic instead.

I think it costs about $90, and they go through your car until they find the problem - all for the same flat fee. Once you know what the problem is, then you could buy the part or fix it yourself. If fixing it doesn't work, you can take it back to them and say they diagnosed wrong, and to keep looking ;-)

 

_________________

EF II Sedan
Ex Chaser, Dual Fuel (Impco LPG)
LSD High, 3.23, Black wheels, other shiny bits.

EB II Sedan <--- R.I.P. (Rest in pieces - gone to the wreckers for $50...... bargain!)

Top
 Profile  
 
 
Posted: Sun Dec 31, 2006 6:17 pm 
Getting Side Ways
Offline
User avatar

Age: 32

Posts: 4146

Joined: 7th Dec 2004

Gallery: 6 images

Ride: E39 523i / EF Fairmont

Location: Brisbane
QLD, Australia

Hmmm, doesn't sound like a bad idea, thanks.

 

_________________

E39 523i
EF Fairmont

Top
 Profile  
 
 
 Post subject: Themostat
Posted: Mon Jan 01, 2007 11:01 pm 
Getting Side Ways
Offline

Posts: 1302

Joined: 10th Nov 2006

Location: Allmods suck so do viruses
WA, Australia

Themostat
normally kills ur power in the morning
make sure theres one in the also it kill ur fuel eco

 

_________________

Your all a bunch of f**k Heads delete this f**k account stupid useless C*** who run this site cant even sell something useless wankers

Top
 Profile  
 
 
Posted: Thu Jan 11, 2007 8:56 pm 
Technical Contributor
Offline
User avatar

Posts: 691

Joined: 1st Jun 2005

Ride: EFII Sedan

Location: Brisbane
QLD, Australia

Just got around to beginning my diagnosis on this problem.

Have started by measuring the resistance of my temp sensor when cold, and when hot.

I get 29.1K when cold, and 3.5K when at running temp (roughly 80 degrees)

I only get one shot at testing various things and have to wait another day till it gets cold to test any more, so tomorrow I will be unplugging the temp sensor and bridging the plug with a 3.5K resistor to see if I can jump straight over the problem at next cold start.

I have pondered a few other things that are only effected by temperature, and the one obvious thing I missed was the air bypass solenoid! Its open a lot more during warmup, and perhaps it is not able to open enough causing a rich condition.

Does anyone know what stradegy is used for the bypass solenoid during WOT? Reason being, the problem only occurs during light to mid throttle, but is not there if you gun straight over that point to take off.

After around 60 degrees of coolant temp, the problem is almost gone, and is completely gone at 75+.

Hows your saga going there, Till? Any new developments?

Also - does your car run on gas?

 

_________________

EF II Sedan
Ex Chaser, Dual Fuel (Impco LPG)
LSD High, 3.23, Black wheels, other shiny bits.

EB II Sedan <--- R.I.P. (Rest in pieces - gone to the wreckers for $50...... bargain!)

Top
 Profile  
 
 
Posted: Thu Jan 11, 2007 11:59 pm 
Getting Side Ways
Offline
User avatar

Age: 32

Posts: 4146

Joined: 7th Dec 2004

Gallery: 6 images

Ride: E39 523i / EF Fairmont

Location: Brisbane
QLD, Australia

Mate I think it might be the head gasket, lol.

 

_________________

E39 523i
EF Fairmont

Top
 Profile  
 
 
Posted: Fri Jan 12, 2007 12:01 am 
Getting Side Ways
Offline

Posts: 1302

Joined: 10th Nov 2006

Location: Allmods suck so do viruses
WA, Australia

ouch that gotta be a real kick in the teeth

 

_________________

Your all a bunch of f**k Heads delete this f**k account stupid useless C*** who run this site cant even sell something useless wankers

Top
 Profile  
 
 
Posted: Fri Jan 12, 2007 12:02 am 
Getting Side Ways
Offline
User avatar

Age: 32

Posts: 4146

Joined: 7th Dec 2004

Gallery: 6 images

Ride: E39 523i / EF Fairmont

Location: Brisbane
QLD, Australia

I sensed something big and gay was up all along mate.

 

_________________

E39 523i
EF Fairmont

Top
 Profile  
 
 
Posted: Fri Jan 12, 2007 6:05 pm 
Technical Contributor
Offline
User avatar

Posts: 691

Joined: 1st Jun 2005

Ride: EFII Sedan

Location: Brisbane
QLD, Australia

what makes you think its the head gasket? Loosing coolant or compression?

Milky oil?

Oily Milk?

 

_________________

EF II Sedan
Ex Chaser, Dual Fuel (Impco LPG)
LSD High, 3.23, Black wheels, other shiny bits.

EB II Sedan <--- R.I.P. (Rest in pieces - gone to the wreckers for $50...... bargain!)

Top
 Profile  
 
 
Posted: Fri Jan 12, 2007 6:40 pm 
Smokin em up
Offline
User avatar

Age: 31

Posts: 264

Joined: 5th Jan 2007

Ride: E-Hybrid Falcon

Location: nowra, nsw
NSW, Australia

ebgizmo, the fuel pump primes up before you even turn the key to start so where are you coming from ?
ever driven a carbied car ? you do have to let them warm up. i know stock as a rock auto's will run 'ok' cold but my manual suffers in the cold, only for a minute or so, if you warm up your engine for a minute or two the ecu won't have to have such a hard time trying to get the car to go. your fighting against primative technology.
warm it up, no worries. not to mention the engine damage caused through cold driving...
i know in alot of manufacturers books it tells you to start up n drive but you have to think about your engine life !

 

_________________

crow cam,cai,exaust,bbm,190 reg & el injectors,xr6 interior,guages,white cluster,pioneer/mtx stereo,big boot install w.i.p, 17"rims,koni/pedders shocks&springs with nolathane re-bush,ssv kit,stainless inserts,clear lights,t5 & short shifter,chardonay/pearl paint

Last edited by vibr8n on Fri Jan 12, 2007 6:44 pm, edited 1 time in total.

Top
 Profile  
 
 
Posted: Fri Jan 12, 2007 6:42 pm 
Fordmods Addict
Offline
User avatar

Age: 31

Posts: 7958

Joined: 1st Jun 2005

Gallery: 13 images

Ride: Falcon

Power: 237 rwkw

Location: Melbourne
VIC, Australia

EBGizmo wrote:
what makes you think its the head gasket? Loosing coolant or compression?

Milky oil?

Oily Milk?

The coolant leaking down the side of his block ;)
If it's getting into cylinders too, it'll be hard to start, and run like a bag of s**t for the first few minutes.
If it leaks enough, it won't turn over at all :D

 

_________________

ED XR8 Sprint - S-Trim, V500, 249rwkw
BF MKII F6 Tornado - 237rwkw

Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 2 of 3  [ 42 posts ]  Go to page Previous  1, 2, 3  Next

Who is online

Users browsing this forum: No registered users and 12 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

 

 

It is currently Tue Dec 19, 2017 7:11 am All times are UTC + 11 hours

 

 

(c)2014 Total Web Solutions Australia - Australian Web Hosting and Domain Names