gas problem....im new and need help

I just picked up a 90 ls and it ran great with no problems for the first week a few days ago I got 10
Bucks of gas at a shell gas station and eversince my car has a har time starting and shuts off when I come
To a stop and it also started to smoke white smoke

Could this be bad gas? Could my injectors be dirty?
I replaced the fuel filter and checked the pump and it works

Any help would be great

Thanks in advance

Smoke indicates a possible blown head gasket .

Stop driving the car and perform a leakdown test. This will tell you if you have a blown Head gasket.

What would I have to do?

I’ve heard about this test but never looked into it

Car is no longer smoking but still shuts off wat can it be?

If you have a blown head gasket and are smoking badly, it’s because you are burning A: coolant or B: oil depending on the color and smell of the smoke, or even both.

If you do in fact have a bad head gasket, and your car suddenly stops smoking, you may have burnt a lethal amount of your coolant and/or oil. Disconnect your battery and do NOT try to start your car until you have fixed whatever the problem is!! If you are low enough on oil and/or coolant your motor will be thrashed, and possibly violently. Check all your fluid levels ASAP.

Did you perform the leakdown test? I highly suggest you do this. I haven’t had to do this in a while, but if memory serves me right all you need is an air compressor, the correct adapter for your spark plug holes, a basic pressure gauge for your air compressor, jack, maybe a helpful friend, a set of good ears and fingers, a wooden dowel if you fancy, and something to manually turn your crankshaft with. There are gauges you can purchase that have two gauges specifically for leakdown tests, I suggest you pick one up or use one in the shop you are using. It will help you quite a bit.

Disconnect negative battery cable. Jack up the car. Remove front driver side wheel. Remove spark plugs/wires, and take off your valve cover. DO NOT LOSE THE BOLTS/GROMETS FOR YOUR VC. Take your long wooden dowel or whatever other tool you prefer (please do not use something metallic or that will break or leave residue in your chamber) and place it gently inside of the spark plug hole until you are stopped by the piston, do not apply pressure to the piston. Use a breaker bar or something with the correct size socket (19mm?), and have your friend slowly rotate the crankshaft until your dowel has moved as far up as it will go for the cylinder you are currently testing. Take out your dowel and have your friend lock the tool he is using in place so that your motor will not turn when you perform the test. At this time the arrows on your camshafts should also be lining up to inform you that you are at TDC for that cylinder. If not, your timing is fucked and you have another problem to fix. Anyway, take a look at your valves. Now that your piston is at the peak of it’s stroke your valves should be completely closed. If anything looks off with them, now is a good time to adjust them.

Take your air compressor and set it to ~100psi. Thread on your plug hole adapter (or the end of the leakdown tester) into the spark plug hole. Let your air compressor open up, and if you are using a leakdown tester, notice how much air you are losing. 10-15% PSI loss is fine, anything above that means there is an excessive leak somewhere. This is where your good ears and fingers come in to play, to find where the leak is coming from. If it’s leaking through the valves you will be able to tell easily. Same goes for head gasket. If you are having a hard time finding the leak, but are losing a lot of PSI there is a good chance it’s running past your piston rings. Test each cylinder the same way.

I hope this helps.

Well the car stopped smoking and my fluids are perfect

I will do the leakdown test just to make sure

Thanks for the help

Great! Let us know how it goes. :up: