97 s420 cranks but no start
 

Just recently timed the engine and put in a new tensioner. Everything was done correctly and the car started immediatly afterwards. The car ran for about 5 minutes then made a loud sucking noise through the intake like it was taking a gasp of air and stalled out. The car started again ran for 3 or 4 more minutes then did the same thing and now it wont start. The engine will crank and fuel pressure is within specifications. Any ideas?

Got Spark?

Got compression?

got compression . I rechecked the timing again and thats good. The car feels like its not firing because it keeps backfiring through the intake

Unfortunately, backfiring in the intake usually indicates timing issues. It does verify spark though.

You might try smacking the base module around a bit. Another way of getting timing issues is to have intermittant timing or intermittant ignition in general. The base module is like a OVP in your car and powers the ME module.

where is this moduel located? The timing is good ive checked it 3 times total and its all dead on.