93 FZJ80 stalls when cold, runs fine warm

[westafari]

@SmokingRocks - required supplies: 6 pack, throttle cleaner spray and a homie with some free time

@Reelitchy - starts up like a champ, idles fine (~800RPM) for 30 seconds or so then bails. It hasn't been cold enough to be running the defroster yet, but temps below 45F seem to trigger the problem

 

[SmokingRocks]

Can you describe the way it dies? Is it suddenly like you turned off the key or is it like its struggling to keep going but runs out of air or gas?

 

[westafari]

It will briefly struggle, tach needle will fluctuate for a second and then just off like I turned the key off.

 

[SmokingRocks]

hmmmm..... Try the IAC fix, its cheap and then report back.

 

[westafari]

So on the way home I tested out the stalling problem after driving for about 5 minutes, that thing just straight cuts off as if I turned the key off. Release gas pedal and boom, off goes the engine. 15 mins is about the amount of time it takes to warm up to where it doesn't cut out. I probably won't get around to wrenching on it until Saturday so we'll see what I can work out.

 

[SmokingRocks]

primary thought is IAC. Try the spray method (use a lot, like the whole bottle), if that doesn't work then pull it apart (its like a level one on the hardness level).

If that doesn't work I've got some other ideas.

 

[westafari]

Pulled my throttle body this morning and cleaned the heck out of it. That thing was pretty gunked up. Noticed that my #2 PCV hose had a serious crack in it where it connects to the valve cover and the hose clamps weren't tight at all. The #2 PCV hose basically exploded/shattered as I was removing it. Cleaned the hell out of the throttle body, tested the IAC and TPS per FSM instructions and then put it all back together with a new TB gasket. Replaced the crap PCV hose and clamps. Temps were around 19F when I started removing the TB in my driveway this morning, definitely good times. By the time I got everything back together it had warmed up but still within the temp ranges that I've experienced the stalling problem and I was STOKED that my truck started up and KEPT RUNNING. So, not sure if it was gunked up throttle body, bad PCV hose or what but for now it looks like my 80 is friendly with the cold again.

 

[westafari]

Before and after pics of TB

 

[SmokingRocks]

Fantastic! might want to consider running seafoam through your engine

 

[westafari]

Yep, just ran a can of Seafoam through there in my last tank of gas. I'm wondering if the problem was the cracked PCV hose this whole time. That thing was crazy brittle and very cracked.

 

[SmokingRocks]

Doubtful, more than likely the IAC. I busted PCV valve will cause the engine to surge.

Have you run seafoam through the intake?

 

[westafari]

Like, through the air intake? Or what?

I noticed that the channel inside the TB after the IAC was full of crud too, I didn't actually pull the IAC off the TB to mess with it but definitely hosed it down good through the aperture and lots of crap came out of it. I'm guessing that was 21 years worth of crud up in there.

 

[SmokingRocks]

Yea, the best way to seafoam is 1/3 bottle in gas tank, 1/3 bottle in crank case oil & 1/3rd bottle sucked through a vacuum line into the intake (you stall out the engine with the last bit of seafoam and let is sit for about 30 mins). On start up you drive the engine to read line a couple times until it doesnt smoke n e more.