run rich only in open loop

I have a 1984 van When starting engine it runs really rich and clouds of smoke out tail pipe and smell of raw fuel I can only assume this is open loop then it will just smooth out and run perfect after a couple minutes or less depending on how warm engine is I can only assume it smooths out when it goes into closed loop I have replace cold start timer switch on engine and it still does the same thing Cant seem to pull codes when jumping diag connector the check engine light stays solid Finding any info on this van is tough If I could just get a wiring diagram it would help I am a 45 plus year technician and can do diagnosis if I can find out info Thank you

Welcome to the forum sorry I don't the answer to your issue but theres a member thats selling a 84' Factory Service Manual that may help?

https://www.toyotavantech.com/forum/...5805#post45805

Good luck!!

JDM

I think your assumption (of an electrical fault) is off the mark.
(It shouldn't run like that, ever)

To have that much fuel on start up, enough to cause smoking and shaking I would be looking at the fuel system.
I would expect to find something bleeding down while it sits, then you have a manifold full of fuel that has to burn off.
Cold start injectors are the usual first suspect, but there are others.
Have you checked fuel pressure and verified that it holds pressure over night?

Anytime you smell fuel you should be scrutinizing everything.
Many a van have been lost to under hood fires caused by fuel leaks.

The search function would also be good thing to get to know, so much knowledge is contained in this forum.