Fordmods Logo

Rough idle and related issues EF XR6 

 

Page 1 of 1 [ 3 posts ] 

 
 Post subject: Rough idle and related issues EF XR6
Posted: Sat Sep 18, 2010 10:06 am 
Getting Side Ways
Offline

Posts: 836

Joined: 1st Apr 2005

Gallery: 4 images

Ride: EF XR6 Wagon, AU2 XR6 VCT

Power: 148 rwkw

Location: Auckland
New Zealand

I am having a regular saga trying to diagnose my idle/ECU/fuel issues. With the J3 chip in, engine cuts out for a second or so, several times, just before reaching operating temp; but not with J3 removed. I have left the chip out to try to diagnose the underlying issues.

Symptoms (with J3 chip removed):
- rough, jerky idle
- hunts 700-900 rpm, especially after giving it a burst at WOT
- poor fuel consumption
- cloud of grey smoke on hard acceleration

Testing done:
- TPS is new, shows 4.08v at idle, .61v at WOT
- O2 sensor shows constant .8v at idle, varies between .7 and -.1 (reverse polarity!?) at anything above idle with no load. Snapping open the throttle gives instant -.1v (negative), then comes back to .7 or so. Sensor shows 9 ohms resistance.
- coolant temp sensor works fine (.8v at operating temp)
- have swapped ISC valve, no difference
- have swapped ECU, no difference (still cuts out with J3 chip in)
- plugs look fine: white to light brown insulators, no fouling
- only diagnostic code is cam angle sensor, but can cam sensor cause this?

Anyone have any ideas? O2 sensor out of range? Vacuum leak? Fuel pressure regulator? Thanks all.

 

_________________

95 EF XR6 wagon, 17" FTRs, DBA, QFM, KYB/Koni, AU block, ported EF head, SS Inductions, Territory intake, MLS gasket, milled, Franklin RH24B cam, Coby headers, no cat, Tickford 2.5", 2800rpm stall, J3 chip

Top
 Profile  
 
 
 Post subject: Re: Rough idle and related issues EF XR6
Posted: Sat Sep 18, 2010 2:09 pm 
Getting Side Ways
Offline

Posts: 836

Joined: 1st Apr 2005

Gallery: 4 images

Ride: EF XR6 Wagon, AU2 XR6 VCT

Power: 148 rwkw

Location: Auckland
New Zealand

Done a bit of research. The O2 sensor is supposed to read between .1v and .9v, and the ECU will try to keep it around .45v, equivalent to 14.7 AFR. If the sensor is contaminated (by silicon, damaged insulator, etc), it will show a lower voltage, and the range will shift downwards.

If mine is reading -.1v to .7v, that would suggest a downward shift of .2v. So, if the ECU is trying to achieve .45v, it is actually over-fueling, as the true voltage is .65v. Is that rich enough to show the effects I am seeing? Also, the fact that it doesn't move from .8v (full rich) at idle must indicate a problem.

 

_________________

95 EF XR6 wagon, 17" FTRs, DBA, QFM, KYB/Koni, AU block, ported EF head, SS Inductions, Territory intake, MLS gasket, milled, Franklin RH24B cam, Coby headers, no cat, Tickford 2.5", 2800rpm stall, J3 chip

Top
 Profile  
 
 
 Post subject: Re: Rough idle and related issues EF XR6
Posted: Thu Sep 23, 2010 5:35 pm 
Smokin em up
Offline
User avatar

Age: 31

Posts: 276

Joined: 14th Apr 2009

Gallery: 12 images

Ride: Fairmont Ghia BA 5.4L V8, AU 6

Power: 205 rwkw

Location: Perth
WA, Australia

Hey Dude,

Had all those symptoms on my BA V8, turned out to be the MAP Sensor. Your's might have a MAF sensor instead of a MAP Sensor, or it might have both. Check all your vacuum lines too.

Good Luck,

 

_________________

Chaos, Panic and Disorder. My work here is finally done.
BA Fairmont Ghia 5.4L. Mods -Full Exhaust, Chipped, Custom Intake, CAI @205.4RWKW.
Stezza - Alpine Type R Splits & 6x9's, Alpine 400w RMS 4ch, 380w RMS Pioneer Mono, 2x12" Pioneer Subs and an AVH-P5950DVD Player.

Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 1 of 1  [ 3 posts ] 

Who is online

Users browsing this forum: Google [Bot] and 7 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 Fri Dec 15, 2017 3:54 am All times are UTC + 11 hours

 

 

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