runs good cold, the won't run at all hot

M

mustangmatt98

New Member
Nov 11, 2013
43
0
0
georgia
Hey all, I got my car running after the cam sensor went out. First and foremost I broke one of the coolant sensors on the outside of the thermostat housing. Since I got the car running again its really hard to start when cold and usually requires to be cranked twice before it will idle. While the engine is cold it runs flawlessly nice and smooth, 30 in hg of vacuum. Once the car starts getting up to operating temp it starts running like crap, sounds like a diesel truck, won't stay idling, smoke comes from the oil dipstick tube when removed, oil cap when removed, between the valve covers, and sometimes the air filter. The car is recently rebuilt and has less than 300 miles on the engine. when the engine cools down it starts up and runs perfect again. I suspected the pcv valve to be bad then I found out these cars don't have one.

I'm at a loss here and I really need to sell this car due to debt. Any help much appreciated.
 
Last edited:
M

mustangmatt98

New Member
Nov 11, 2013
43
0
0
georgia
jetjock;2021447 said:
Was it timed after CPS replacement? It'd also help to know which sensor got busted. And even if 30 lbs of vacuum was inches of mercury you still wouldn't be on this planet...
Click to expand...

My bad on the lbs instead of hg, I've fixed it to avoid further confusion. as for the sensor it is the one on the bottom of the thermostat housing. I did re-time the car using the procedure I found on here. Jumper wire between 2 of the terminals in the diagnostic box...same ones for check engine light.

hvyman;2021448 said:
Fix the sensor. Vac should be at 17-20 in hg at idle.
Click to expand...

Is the sensor telling the computer the car is cold and adding more fuel? Would this cause more crank case pressure? Will the sensor cause the vacuum to be higher?

I will fix the sensor when I get home from work tomorrow.
 
M

mustangmatt98

New Member
Nov 11, 2013
43
0
0
georgia
jetjock;2021551 said:
The only coolant sensor that can effect fueling is the two wire one on the engine side of the thermostat. As for 30 inhg, the death spiral of science education in America continues...
Click to expand...

::dead horse::

I went at it as soon as I got home from work today, fixed the coolant sensor, and put new rubber hoses on everything in the pcv system. I was about ready to take the car for a ride to see if she was fixed and started checking fluids before I went on my way. I pulled the rad. cap and found that it was empty began to fill it up and the fluid I was putting in was coming right back out. I crawled under the car to find the source of the leak and the furthest back freeze plug on the pass. side was missing. I repaired that filled the coolant back up and went on a ride. Car now runs perfect with no ill effects.

I had the freeze plugs put in at the machine shop. I think I will not be using that shop again. I think what probably happened was the plug came out while driving and the broken sensor was not showing on the gauge that the motor was over heating and all my issues were caused by this. I never saw coolant on the ground and never saw the heat gauge rise from it's normal position. This is just a guess though.

As for the vacuum issue it is still excessive. I suspect maybe a timing issue. What would happen if the CPS was 180 degrees out?
 
You must log in or register to reply here.
Top Bottom