Hello , I’m new to the forum, I have a 86 Oldsmobile 98 that I purchased in January and I live it , car ran like a top , so anyhow one day in June I was driving to work just did a oil change and I’m on the freeway and it shutdown on me , so I get it towed to mechanic , come to find out the crankshaft broke , so I went ahead and replaced everything that could be replaced while we had engine busted down and also new parts on outside like sensors oil pump Ect, so we get the motor back in and started but now it has a problem at idle with shaking and some faint popping out of exhaust while under a load it gets worse , we have checked compression and all sensors, coils, plugs , injectors, and everything is working as should any help or knowledge on the situation is greatly appreciated.

Sounds like something is out of time or the spark plug wires aren't connected in the right order.

Welcome aboard!

thanks , yeah we’ve checked the wires and any other order that’* given and car doesn’t run right so we know it’* right order , we also thought that , now as far as the timing , it doesn’t have a distributor and the timing chain was out in correct with the dots lining up , really only 1 way to put timing chain on , what we are trying next is changing out the old harmonic balancer which is a 1 piece with the recommended 2 piece that the new crank sensor said to get , I really don’t see why the balancer would be the problem but I’m up to try any and everything at this point lol

A busted crank? Was the block even sent out for magnafluxing? Heads? I'm suspecting there is more damage.

yes , flux the block and all new heads pistons rings cam anything that could be replaced , was replaced

Compression numbers? If compression is good across all cylinders then look at the KV wires. You don't want to rely on the numbers on the coils when installing the wires. They are likely not in the right order. Go by the placement on the diagram.

I am starting to believe it’* this camshaft interrupter sensor , this is the only thing I haven’t replaced and I googled it and all the symptoms of a bad one is all my problems wrapped up in one , the bad idle the acting like timing is off , when everything was assembled correctly , does anyone know about these camshaft sensor interrupters ? My understanding is they go begind the can gear and send magnetized signals to the actual cam sensor ??? Idk but I do know I have one and we didn’t really know what it was and could very well be the culprit

Interrupter? That ignition system does use the cam sensor input at the module. Is the module new? Sounds like module would be more suspect than the cam input.

yes I’ve replaced every sensor , icm, all coil’* and plugs and wires are getting fire , cylinders have 150+ on compression check , both heads are new so no stuck valves , new timing kit the whole 9 yards , this interrupter is the only piece that we didn’t replace , also cleaned it in the parts cleaner and don’t know if the little brass piece is on there but I just ordered a new one

That looks like a knock sensor.
The diagram I put up is the wrong one. That is for the 3.0L engine.