Multiple codes 14, 31, 41, 42

M_31_07

Member
Authorized Seller
Joined
Jan 18, 2009
Messages
211
Location
San Jose, CA
Hey everyone, thanks for taking the time to look into this thread. I just recently got my 1JZ rebuilt a couple months ago and have since put about 2000 miles on it. Just recently about a month or so it started acting up giving me multiple engine codes. I'm still on the stock 1JZ ecu(had the capacitor service done at Driftmotion back in 2008/2009) at the moment it's giving me codes 14, 31, 41, and 42. Before the build I never had any problems with it or even after, up until now. I'll try to explain this the best that I can.

- ONLY happens on cold start up and never after it gets warmed up. On a cold start up it has a pulsing idle(stays around 650-750), but never dies
- On neutral when I try to apply full throttle the car doesn't die, but it won't rev. If i apply throttle progressively though rpm's go up but not past 2000. Also it does this if I drive while the CEL is still on, not revving past 2000-2300.
- After 20 min or so +/- that's when all CEL's disappear and car runs like normal as if there isn't anything wrong. When this happens no codes appear when I jump the terminals.

Hopefully the ECU is just fried and maybe needs capacitor service again? Any input is gladly appreciated.

I don't know if this helps, but this is my current set up:
OEM spec engine rebuild
Hot tanked
Head port/polished
3 angle valve job
ALL seals and gaskets have been replaced
Factory Toyota piston rings, main bearings, rod bearings, & thrust washers
Factory Toyota oil pump
Factory Toyota water pump
New Timing belt hydraulic tensioner
ARP head studs
ARP main studs
ARP rod bolts
Fuel Dampener bypass hose
MKIV fuel pump
T4 divided exhaust manifold
46mm wastegate
Master Power T70 with .70a/r
Aeromotive fuel pressure regulator kit
Stock 1J ecu
SAFC Neo
 

hvyman

Dang Dude! No Way Man.
Staff member
Super Moderator
Authorized Seller
Joined
Apr 17, 2007
Messages
12,768
Location
Tokyo,jp
14 igniter
31 afm/map
41 tps
42 vss

Wouldnt hurt to open up the ecu, but the fact that it goes away makes me think not.
 

IBoughtASupra

Active Member
Authorized Seller
Joined
Mar 10, 2009
Messages
4,455
Location
Queens, NY
Hmm, only on cold start? Did you try replacing the ECU coolant temperature sender?

I did the exact build you did, but I have cams in the head. It does run slightly lean at idle. If it is only at cold start up, we have to check what changes when the engine is cold to when it is hot and that is the first thing that comes to mind. Is it running rich?

Tried to replace the MAP sensor? Check to see if they have a ground, 5V and a signal when this is happening? Get the pinout for your ECU, Soarer or Supra, and check to see if all the wires are function when cold. It really won't make a difference when the wire is hot to cold but my point would be, the ECU controls the 5V to the MAP and TPS, so maybe there is something wrong when the ECU is cold, rather than running for a period of time.


When you say this happens cold, do the symptoms go away as the engine's operating temperature rise up? Do you have a wideband? What's the engine AFR idling at when it is cold?

With all this said, check the ECU first. It's a common failure point.

If you have the funds, get the 1JZ AEM kit from DriftMotion. It is put together very well.
 

M_31_07

Member
Authorized Seller
Joined
Jan 18, 2009
Messages
211
Location
San Jose, CA
Thanks hvyman and Iboughtasupra for your inputs. I found the problem, it was just the igniter I replaced it with a good working one and everything went back to normal. Weird how one thing makes all these other codes pop up. So now no more codes, everything is back to normal. As for the AEM ecu from Driftmotion, that's on my list of things to do in the near future. Again, thanks guys.