Running bad when cold

[FMXVAN]

Hi, I have almost finnished putting crown engine into my hiace van. I have had the engine running and been driving around for a day. The engine runs mint once up to temp and will start fine when cold but it wont run properly when cold. The RPM gauge jumps up and down when you are between 1000rpm and 3000rmp and has a difinite missfire.

Its like the ecu dosent know the engine is cold and needs to run a differnt map. but my temp gauge on the van works. Do they share the same feed?

Any help would be great

 

[Peewee]

They have different sensors for the dash and ecu.

If you have the pinout of your ecu unplug it and measure the resistance of the coolant temp sensor, and then compare it to here.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=113

 

[FMXVAN]

Cheers for the info will pull apart over the weekend if need be. Found somthing interesting last night i got my engine cheeck light going and the only code it is pulling is 13 which is RMP circut No.2 Sounds important to me and could be a contributing factor. Can any body let me know what purpose this circut has, My rpm gauge works fine.

Thanks

 

[Peewee]

Clear the codes and try again.

It could be something stored from a while ago.

I can't remember exactly what it is, but its either one of the cams sensors, or one of the ignitors.

 

[FMXVAN]

The problem has been solved after replacing Leads, Rotors and Dissys. It was infact the Cam belt out 1 tooth. Strange it only did it when it was cold but never mind.

Thanks For your help

 

[sideshow]

its been said millions of times on here u should have searched
ive found 20 instances on the net which say tooth out
would have saved u buying leads rotors etc but atleast they are done now

code 13 generally means tooth out on 1 cam
very common for guys who dont normally do timing belts on these
i think even when hot it still would have run a tad slower
maybe just when cold u noticed it more due to bit richer mixture

 

[FMXVAN]

There was absolutly no signs of bad running when hot. I didnt think it would have been the belt because i have done many cam belts. I must have been daydreaming when i did this one as it was 2am in the morning.

Thanks Any Way

 

[Peewee]

I'm surprised the ECU didn't throw a code.
Unless it only throws a code when one of the cams is out, and not the crank.