98 econoline wont start

I just bought a 98 ford econoline with 140000 miles on it, it just lost power on the hwy and and when i try starting it, it backfires with smoke coming out from the tail pipe. since then it wont start, the mechanic says it is not showing any code and we cant find what is wrong with it, i will be greatful if someone can help me.

have you checked the valves???
its possible your valves are shot valve seals as well that would let oil onto your motor(black smoke) and the backfiring would be your vales arent closin in time when the xplosion happens in the chamber,

chek it out , i hope im right , let me know

have you checked the valves???
its possible your valves are shot valve seals as well that would let oil onto your motor(black smoke) and the backfiring would be your vales arent closin in time when the xplosion happens in the chamber,

chek it out , i hope im right , let me know
Thank you for your reply, i found out that the BOLT attaching the pulley to the crankshaft broke, my mechanic took the whole engine to a machine shop and the part of the bolt that was inside the crankshaft was drilled out, and a new one was put in it, then the engine was put back in the van. It cost me a grand, it ran for 2days and it happend again. I would like to know what the problem might be, and if replacing
the crankshaft will solve it. Thank for your help.

Thank you for your reply, i found out that the BOLT attaching the pulley to the crankshaft broke, my mechanic took the whole engine to a machine shop and the part of the bolt that was inside the crankshaft was drilled out, and a new one was put in it, then the engine was put back in the van. It cost me a grand, it ran for 2days and it happend again.

Your mechanic is telling you stories. There is NO WAY he "took the whole engine to a machine shop", and did the job for $1000, or even $2000. Man it is a LOT of work to pull an engine from a van.

The bolts used in your engine are SINGLE USE, and you MUST use only the factory bolt. My guess is that someone replaced the front main seal, and re-used the bolt (or did not torque it properly) and it broke. The reason it ran poorly was the crank trigger wheel is clamped between the crank and the harmonic balancer (pulley) by that bolt. When it breaks, the trigger wheel slips, and the computer does not get correct information.

The new bolt was either not torqued properly, or the crank threads cannot hold any longer.

Your mechanic is telling you stories. There is NO WAY he "took the whole engine to a machine shop", and did the job for $1000, or even $2000. Man it is a LOT of work to pull an engine from a van.

The bolts used in your engine are SINGLE USE, and you MUST use only the factory bolt. My guess is that someone replaced the front main seal, and re-used the bolt (or did not torque it properly) and it broke. The reason it ran poorly was the crank trigger wheel is clamped between the crank and the harmonic balancer (pulley) by that bolt. When it breaks, the trigger wheel slips, and the computer does not get correct information.

The new bolt was either not torqued properly, or the crank threads cannot hold any longer.
Thanks for the reply again, it cost $600 to pull the engine and $250 to drill the bolt out of the crankshaft in the machine shop and some more $ to buy other things like a harmonic balancer etc. I believe i would have been better off if i had just changed the crankshaft, because it looks like there is something wrong with it. Now i am going to spend about the same thing to replace the crankshaft. Can someone tell me if this is a good idea. Thanks to all.

Thanks for the reply again, it cost $600 to pull the engine and $250 to drill the bolt out of the crankshaft in the machine shop and some more $ to buy other things like a harmonic balancer etc. I believe i would have been better off if i had just changed the crankshaft, because it looks like there is something wrong with it. Now i am going to spend about the same thing to replace the crankshaft. Can someone tell me if this is a good idea. Thanks to all.May have been better to get an engine out of a wrecked van or trade for a rebuilt. Seems you were not careful when buying it.

I would NOT under ANY circumstances replace the crank or buy a "rebuilt" engine, but I WOULD buy a low-miles USED engine. Most likely it will be 1/3 the cost of re-built, and will last 5x as long.