'87 Cressida Idles poorly after a high speed run

[battlecat]

So let's say I take a run down the interstate....65-75 mph...drive a half-hour or more....then pull off the interstate. pull up to a store. Cut 'er off...go in, come back, crank 'er back up...then it will barely idle at all. Don't have this problem otherwise...what could be causing this?

[84Cressida]

I have the exact same problems you do. I went on the Scotty Kilmer website and he told me it is excess heat causing a gas build up in the engine. If you rev the engine it will clear out and run normally right? He said his Cressida does the exact same thing (he has an MX83!) He says a special winter gasoline formula causes this problem and to fix it would involve re doing the whole vaccum system.

[battlecat]

Originally Posted by 84Cressida

I have the exact same problems you do. I went on the Scotty Kilmer website and he told me it is excess heat causing a gas build up in the engine. If you rev the engine it will clear out and run normally right? He said his Cressida does the exact same thing (he has an MX83!) He says a special winter gasoline formula causes this problem and to fix it would involve re doing the whole vaccum system.

Wow! Haven't though of that! When it happens, I only "blip" the throttle a little to keep it running, but I've never really "revved" it. I did figure it would be a possible vacuum problem, but the "gas build up" thing confuses me a little (and the first time it ever happened to be was in the summer, if my memory serves me right). Thanks for the suggestion and I'll explore this!

[84Cressida]

Does the car run normal otherwise? Cause mine runs fine once you get it going.

[battlecat]

Originally Posted by 84Cressida

Does the car run normal otherwise? Cause mine runs fine once you get it going.

Yeah, runs fine once underway....

[kamesama980]

oh, he means vapor lock...it's possible but usually that causes a stall/no-start condition.

[battlecat]

Originally Posted by kamesama980

oh, he means vapor lock...it's possible but usually that causes a stall/no-start condition.

Ooohhhh...I THOUGHT about possible vapor lock, but like you said, Kamesama980, this isn't "vapor lock" behavior, exactly....

[84Cressida]

Originally Posted by kamesama980

oh, he means vapor lock...it's possible but usually that causes a stall/no-start condition.

Mine has idled so low to the point that it did stall but it would start back up. What is vapor lock exactly?

[kamesama980]

Originally Posted by 84Cressida

Mine has idled so low to the point that it did stall but it would start back up. What is vapor lock exactly?

fuel gets so hot it evaporates in the fuel lines. the fuel system is calibrated for the density of liquid fuel so the engine doesn't run. less of an issue with FI and return type pressure regulators (unused hot fuel dumps back into the tank to mix with cold fuel and dissipate heat through the tank) was more of an issue with carbs because of low pressures and lines ran next to the engine longer (mech. pump to carb) and a carb sitting on a warm part of the engine