Richer than Scrooge McDuck
 

1986 reg cab 22rte pickup, manual trans. 4x4

For the past several months my truck has been running rich at idle...so rich that it misses terribly and the exhaust smells like raw fuel. Also when cruising under very light load it will miss too. Never under normal or heavy load or WOT.

It has been doing this basically since I did my head gasket, it may have done it before but has been getting progressivly worse.

I have passed this off as bad injectors (they had 312k miles on them) untill this weekend when I replaced them with brand new ones from LCE. The problem got worse!

I'm assuming that its worse because the new injectors are not gummed/plugged up like the old ones. They also do not leak down in between running as the truck fires right up instantly now during cold starts...it used to crank a few seconds first.

New in the past 6 months:

Plugs
Wires
Cap/rotor
T-stat
O2 sensor
Injectors
Fuel pump
And all the headgasket stuff etc.


So after I found that the injectors did not solve the problem I checked all the vacuum lines routing, they were fine. No vacuum leaks either
CSI is not leaking.

I have a new pressure regulator but haven't installed it yet... I also don't have the means to check the fuel pressure...

I checked the TPS...resistance was higher than spec in the closed position... Also the throttle stop screw was not contacting the throttle... So I adjusted the screw per the FSM but ran out of time to set/check the tps(what a pain!) Terrible screw location on these engines!!! 4age's are much easier!

I ran out of time to adjust it and this is my daily driver so I had to take it to work today. ˟On the way to work (30 mile trip) the check engine came on breifly twice...checked the codes and got a 5,7, and 56? Which doesn't exist?? ...the flashes weren't as easy to decifer as my last 80's toyota.... The pauses weren't long enough or something.....


Anyways I'm hoping that it is my TPS that is causing all this grief...

Any input or advise is welcomed, I will update as I discover more. ˟

In the meantime I hope I don't get too many red lights on the way home as the thing sometimes dies at idle its so rich!

any intake leaks?
bad o2 sensor?
exhaust leaks before o2 sensor?

No intake or exhaust leaks.....


UPDATE:

I sucessfully set the TPS last night. It now reads within spec in all areas.˟ The idle improved a bit. It isn't soo rich that it almost dies anymore...but it still has a pretty stacatto miss at idle.


I drove it to work this morning...check engine light came on several times...I discovered that it would come on during light cruise and I could make it go away by accellerating for a few seconds...

It also runs pretty smoothly when its cold... Ie no o2 sensor effecting the mix.

Cleared the codes last night. Checked them this morning at work...only code 5 now...
Thing is its a new Denso o2 sensor since the headgasket...could be toast already?

One thing is that I have repaired the o2 sensor wire...there are two waterproof butt connectors which are then shrink tubed... Maybe the wires are no good? How could I check that? Or just buy another sensor and see?