AFR 10.0 at Idle?

[Mark2]

I have been running this setup with no changes for the last year with no problems at all.

- Lex afm and 550's
- hks intake
- hks dragger exhaust
- 3" defcon dp
- blitz ebc
- hks bov
- spearco ic
- fjo wideband

The car has run like a champ for the last 10,000 miles. I used to be able to hit 15 psi with no problems at all but now my engine cuts out abruptly at anything higher than 11 psi. Now suddenly this morning my idle, which used to always be a steady 14.7 is now reading 10.0 and the car seems to choke a little at idle. The engine light has started going on the richer the car runs and especially at idle. I have checked for boost and vaccum leaks and have found nothing.

I know I need to get something to check the engine codes but does anyone have any other ideas on things I could check.

Thanks Guys.

 

[grimreaper]

yea the codes

 

[Mark2]

I hooked up a code reader and it kept looping through the number 3 1 3 4. It's one of the older readers that flashes the engine light as opposed to having a nice display.

It's strange because the car will idle normally at 14.7 at one light and then I feel a kick from the motor at other lights and the afr's drop to 10.0 and the exhaust blows black smoke.

The last time I drove the car, it was choking at idle when at 10.0 and even at 14.7 afr. It's really strange and the symptoms seem to changes ever time I drive the car......which probably means I'm making it worse by driving.

Thanks.

 

[s383mmber1]

Appears to me you might have codes 31 and 34. Use this link here to check the codes using the diagnostic box just to verify that it is codes 31 and 34.

http://www.cygnusx1.net/supra/TechTips/engine_error_codes.aspx

My guess, is your AFM went.

 

[Mark2]

Appears to me you might have codes 31 and 34. Use this link here to check the codes using the diagnostic box just to verify that it is codes 31 and 34.

http://www.cygnusx1.net/supra/TechTips/engine_error_codes.aspx

My guess, is your AFM went.

Yep, now that I have the codes and have searched it seems that it could very well be the AFM. That would explain why I'm running super rich. The car drives alright as long as I'm moving so I should be alright to get this thing home and then I'll have a closer look. Hopefully it's just a bad connection.

 

[Mark2]

So, I checked the AFM connection and it was just a little bit loose. Loose enough to cause my extremely rich idle. I plugged it back in and all is well again except I still hit what seems to be fuel cut at around 11-12 psi as opposed to be able to run 15 psi like I have been for the last year.

I checked for boost leaks and found nothing. The only thing I can think of that has changed is I've been running 91 octane gas for the last month as opposed to 94 like I used to run. I'm not sure if this could cause issues.

 

[Mark2]

Update on my vehicle problems. I have been running approximately 12 psi the last couple of weeks. My car seems to cut out, very much like fuel cut, but only if I build boost really quickly. For instance, if I do some third gear pulls I have no problems, but if I'm in 4th or 5th and drop down to 3rd and mash the pedal, I get up to 12 psi quickly and then bang; it's like hitting a brick wall. My car is still throwing a code 34 as well.

Any ideas?

Thanks Guys!

 

[gaboonviper85]

Your codes are already telling you what's wrong! Fix it...

When was the last time you changed sparkplugs?

Make those codes go away and run better fuel and do a full tune up.

 

[Mark2]

So last night I went over everything and still haven't been able to pin down the problem. I have new plugs and wires and a full tune-up and I still can't boost past 10 pounds. I've tightened everything up and still haven't been able to find a boost leak. I'm going to go ahead and make a boost leak tester and see where that takes me.