My 1996 7.4 thunderbolt ignition motor has ran few hours (200h?) prior I bought him last month.
If I start the motor, he idles very stable and nice around 600 rpm cold.
At a sudden moment, the rpm drops like as if the ignition is cut for a partion of a second, but mostly the motor recovers directly and idles normal directly after.
Sometimes as the cut-out takes too long, it stalls. I have to start him again.
I tried running the idle rpm's higher, giving it some throttle till around 1200 rpm, but the same fall-outs occurr, and he stalls as frequent as on low rpm.
The motor sounds great though, and rev's up fast and good even cold.
Once the motor is warmed up (this takes 4 to 5 minutes) it runs and sounds great, and the problem completely dissapears.
Since I bought him I made a couple of short trips after good warm-up without any motor hesitation or problems at all, and also high top rpm and speed.
Untill warm-up I get around 20 dips of which about 3 stall the engine.
Very strange problem, and I am searching in this forum for days now, without finding something comparable.
Thanks for any advice.
If I start the motor, he idles very stable and nice around 600 rpm cold.
At a sudden moment, the rpm drops like as if the ignition is cut for a partion of a second, but mostly the motor recovers directly and idles normal directly after.
Sometimes as the cut-out takes too long, it stalls. I have to start him again.
I tried running the idle rpm's higher, giving it some throttle till around 1200 rpm, but the same fall-outs occurr, and he stalls as frequent as on low rpm.
The motor sounds great though, and rev's up fast and good even cold.
Once the motor is warmed up (this takes 4 to 5 minutes) it runs and sounds great, and the problem completely dissapears.
Since I bought him I made a couple of short trips after good warm-up without any motor hesitation or problems at all, and also high top rpm and speed.
Untill warm-up I get around 20 dips of which about 3 stall the engine.
Very strange problem, and I am searching in this forum for days now, without finding something comparable.
Thanks for any advice.