1992 ssei

This is my first post so sorry if I don't get things right.
I have a 92 ssei s/c that won't fire on #5 cyl New coil paks plugs wires water pump still wont fire. Someone told me it might a valve. New cam & crank senser. What else could there be? Only has 101k miles. Also getting a smell of unburnt gas. I did have the injectors check by a mechanic and they are good. I have no codes. Any help?

Welcome to AF!!

Based on your description everything should work right. There is a possibility that one of the valves on number 5 is not working right or is damaged. The best way to check would be to do a compression test to see if everything is OK. If you test the other cylinders and get a low reading on #5 then I would suspect something is wrong with the head or the rings on that cylinder are bad. Once you do the test post the readings and someone can help you with the next step.

GTP DAD thanks for responding. I will get that checked this week and will post results.....If it's a bad head may just put it up for sale..sooo tired

Have you replaced the ignition module? If not, you can remove it and if you have an advance auto parts near you, they could check it for you for free. I don't know what autozone's policy is on that though.

Beside the unburned gas smell, is there any other performance indication? I'd do a fuel rail pressure check in case injector 5 stays open: fuel rail pressure should maintain around 45 psi for some time...a few minutes..after the engine is turned off. If pressure falls right away, it means stuck injector (s). This would explain only cylinder 5 shows bad...cause otherwise, since there are always two cylinders fired at same time, a real spark problem on the electric side would show on 2 cylinders (2 and 5)...
www.avigex.ca/xport/3800firing.jpg
You can swap two injectors one for the other (like 3 and 5) to see if the problem switches places....

I have the at a mechanic now for a compression check. As far as performance some of the time when w.o.t it may sputter like back fire or something sometimes it wont. Around town it real slugish. I get it back from the mechanic (A friend that has a shop) this evening.

Well got the car back today compression is as follows #1,130/#3,128/#5,128
#2,125/#4.125/#6.127. This was done while car was luke warm. Did another code check from Schucks Auto and came up this time as a oxy sencer is bad.
Didn't think of that, would it cause it to missfire? The part is only $23 so b4 I spend another dime on this what do you think?

Verify that the computer is actually firing the #5 injector, or that the #5 injector has the proper resistance across it. My 95 Buick had a problem where the computer was not firing the #4 injector, causing a misfire. Once I replaced the computer everything was fine.:lol: Make sure you troubleshoot first before you just go and replace the computer!:nono:

If you got an O2 sensor code change it with a new one. This could account for the gasoline smell. What ChemMan said is correct check the injector to see if it is receiving a signal from the computer. This is done with a noid light, fairly inexpensive at autoparts stores. If there is no signal to the injector that may indicate a bad injector, bad wiring or bad computer.