starting issue

I have an 87' I6, 5 spd, thats developed...and issue. It starts right up every morning, then after I drive it for 5 to 10 mins if I hafta turn it off it wont start again. It just keeps turnin over. On occassion when I first turn the key, all the power to the whole vehicle flickers. After the initial flickering, it wont do it again, but still just turns over...and it doesnt flicker all the time, its just occasionally. However, if i let it sit for 5 to 10 mins the darn thing will start right up like nothin ever happened.

Ive changed the plugs, cap, rotor, wires, checked the fuel pressure and they all are fine. However, after I did this, It started missing while driving and running rough (i did gap the plugs too). Anyone have any ideas or experience with somethin like this?

Power flickering is indicative of a connection/ground/electrical issue. I would start by freshening all grounds. Your vintage (RENIX) is extremely sensitive to bad grounds.

If it was a true thermal failure of a component, the engine should die when heat is built up on that component. But yours runs until you turn it off. Never just dies on its own?

The one thing that could be suspect would be a cam sensor. When a cam sensor has a failure, the ECU will calculate spark timing based on the last camshaft position sensor signal and the engine will continue to run. However, the engine will not run after it is shut off......because of this characteristic, it might be worth a try to test the cam sensor IMMEDIATELY when this happens. Testing it when the vehicle starts may be of no value.

Good luck and keep us posted. This one is interesting.

ok, so after some more tinkering, i noticed one of my plug wires wasnt on right and it was arcing of the engine block (not my brightest moment). so after i fixed that issue, it ran MUCH smoother, and ive taken it out twice with no more start issues thus far. im gonna keep doin the short runs through tomorrow and see how it goes. will keep you posted on the outcome and check the cps as well.
Thanks again

oh, and no it didnt die when up to running temp....it would actually start fine again once its at normal running temp.