put, put, put, POW!!!!
 

Hey guys, the other day driving Katie she decided to be a *****. She was driving fine. I turned her off for about 15 minutes. got back in and started her up and all of a sudden she acted like she was out of gas just no power and spitting and sputtering. she ran for another 2 minutes made a very very loud backfire and then shutoff and now she turns over fine but no cigar. Im still learning all this CIS stuff so please help me troubleshoot in babysteps (3.0 in 81 SC)


Thanks!!

How old/new is your fuel filter? Are you current on your maintenance? That is where I would start.
My car is an 86 so I have no experience with CIS; sorry.:(

Take off your air filter cover and look behind the filter element for the pop-off valve. Is there a pop-off valve installed? Did it get stuck open? We can guess that you had some fuel pressure related problem which led to poor running. The poor running led to the backfire in the intake. Many CIS cars are fitted with a pop-off valve to save the airbox during a backfire. If you are lucky, you have one and it saved your air intake. Look and report back. The reason your car is not starting now is likely because you have a massive air leak. Let's hope it is a stuck open pop-off valve rather than a shattered air box.

Blown air box.....

+1

Only times I have had a massive backfire has been when I forgot to re-attach some big honkin' hose that ties into the intake system. Same symptoms as a stuck open pop off valve/ blown air box.

1980-83 Air box
 

If you find that you need an air box, I have a good one that just came off my 1980 SC coupe. It already has a pop off valve installed.

Fred, I may need one, mine appears to have been blown by clue of a missing screw, if it runs/starts/idles fine, should I care?

If air box is fine check oxygen sensor relay under passenger seat. You should always carry a spare.

When it fails you will see symtoms exactly as you described.

Also look at your rotor. If it cracks/breaks you'll also see same symptoms.

Check your coil
 

Had similar issue, it was my coil. The PO put a conventional coil on it and it inevitably died. I put a MDS Blaster coil on and it solved the problem. A bosch coil is original and pricy.
My 2 cents

Airbox go boom, sorry!

Hey Guys My car has an aftermarket airbox installed but no pop off valve i dont know the brand its just carbon fiber and yeah.. i will change the fuel filter tommorow.. as for the airbox it doesnt appear to be cracked or anything like that.. and what exactly what i be looking for in that 02 Relay under the seat?


feel free to email me @ warrent22@gmail its quicker for me

First thing to do is see if your oxygen sensor circuit is working. Open the front hood and if the light works in the trunk the O2 circuit should have juice. If not, look for a blown fuse. The plactic cover over the fuses indicate which one is the O2 fuse. I believe it is the 4th fuse away from the driver position.

The relay is a silver cube about the size of an old school flash bulb if you remember cameras when they had film. :) It is under the passenger seat and it has a clip on it holding it in place. You'll have to take the seat out to get to it.