ASD Circuit triggers when engine temp reached 220

Hello all... I have a weird problem that has been going on for a couple years now... It only happens in the summertime, and usually when towing... When the engine temp reaches approx 220 degrees (well below overheating) the engine will shut down and will not start again until it cools down below 190, it will turn over just no start... After it cools down, it cranks right back up as if there was never a problem and off down the road we go again till it reaches approx 220, and the same thing, shut down... It has to be the ASD circuit being triggered because I have no fuel and no spark, but what is causing it??? I have searched all over the internet and in every forum I can find and no answers... In my quest to conquer the problem, I have installed the following some obvious, some not so obvious...

New Aluminum 3 row radiator, thermostat, temp sensor, Gen rite Hood Louvers, CPS, TPS, MAP, NSS, Had an overdrive Solenoid go out replaced that too... My Jeep has a factory axillary transmission cooler on it already but I considered swapping it out for a larger one... Any other ideas???

Maybe the PCM sending funny signals??? Just thought of that one...

What year/engine? Any check engine light? If so, pull stored codes for guidance.

I'd look into keeping that engine temp ROUTINELY down to the 200-210 range. How much weight are you towing?

Some brainstorming here.....

Does the fuel pump run when you turn the key to the ON position when it is in a no-start condition?

Have you actually checked for spark when this occurs? Ignition coils can have a "thermal failure" as well; they can be tested for primary/secondary resistance. Test when symptomatic

ASD circuit has a relay in the power distribution center under the hood. Could try swapping that relay with another as those relays are all of the same part number.

jghall said:

It has to be the ASD circuit being triggered because I have no fuel and no spark

Click to expand...

crank sensor and cam sensor will have the same effect

1997 Cherokee Sport, 4.0, no Check engine light, no fuel pump, no spark (I have checked)... As far as weight, I was towing my pop up (2400lbs), that I tow all the time... Like I said it only happens when it starts getting hot outside... It does it on occasion in the heat of the summer while idling in traffic... I have solved the issues while idling though when I installed the larger radiator and the hood vents...

I would put my money on thermal failure of the CPS/CKP crank sensor.

Possibly thermal failure of the coil, but much less likely.

joe_peters said:

I would put my money on thermal failure of the CPS/CKP crank sensor.

Possibly thermal failure of the coil, but much less likely.

Click to expand...

i agree, the op needs to keep in ming that the cps/ckp signal is needed for the pcm to energize the asd relay.

FWIW, another vote for crank sensor.