R59

Ok Guys, here is one for you.... 96 LT1 Auto coupe....
The wife was diving along...when she hears a pop or bang???
Anyway, the car stalled and would run very, very rough....

I get it home checked the codes...no codes.. DANG!
I found the fpr leaking, so I replaced it all ok there.....
The car starts and runs very rough and I can smell fuel, like it's flooded, and it acks like it's flooded...

I tried to clear the flooded state but no change...The car has been sitting for 2 months now, still no change when I tried to start it today....


The fuel pressure is good, there has to be some spark... The smog pump cycles on and off... I have not looked at the plugs, I don't want to chase my tail in circles, until I have some idea where to start. I have a FSM for the 94....any ideas on where to start on this
Thanks for any help on this one

0Paul Ruggeri

You said its running rough, does it make any unusual noises?

R59

No, there is no banging or sounds that are blown engine related.

seems to run on one cylinder maybe two....

R59

Ok just talked to the wife....
She says it just sputtered out and sounded like a flat tire not a bang or pop!...GO FIGURE!! woman and their decriptions

jaa1992

Check the injector fuses, I drove my 92 over railroad tracks once and after it ran like crap, barely made it home. Parked it for a few months thinking I had something major wrong with it. Turned out to be one of the injector fuses.

In a dark garage start it and see if you see a light show along the plug and coil wires

Just a couple more ideas

R59

Thanks....The injectors are all working.... I changed the plugs..no help..
I just talked to the wife again and after a little meeting of the minds She said she nailed at a red light and it sounded like air escaping like a flat tire sound when it died
there doen't seem to be coolant in the oil.....but she said it had been losing coolant , but not leaking any

so I am thinking head gasket??? opti???
Is there a test for a blown head gasket?
would the engine not run if a head gasket is blown?
Is there a compression test I can do with the engine not running?
I have no idea where to begin on this one..
I am in Phoenix anybody want to help with this?? Thanks in advance

airplane50

What method did you use to check codes, paper clip or scan tool? If the opti is the problem there should be codes set. Whatever method you used to check for codes try the other. The loss of coolant is a concern. Did you look at the coolant to see if there is any signs of oil?

R59

I used a scan tool for the codes, and the paper clip method...I am however going to check the codes again with the paper clip. I will post the results...

Doesn't seem to be oil in the coolant...key word "seem"

The check engine light is on so...there should be codes I guess...

The scan tool shows some things...5 inc, catlyst, sec air, o2 snsr, o3 htr, EGR.. Then it shows 3- misfire, fuel, comp.....not sure what all that means...
Thanks for your reply!!

R59

Thanks seabright I have that link.... paper clip shows C12, C62, H61, H62
my scanner shows..no codes

lt4obsesses

well. "sputtering" and "air escaping" kind of sounds like a rather larger vacum leak. Perhaps something got lose or broke off?

As far as the head gasket, also check for signs of oil in the coolant. A leak in the head gasket can flow oil into the water passages as well. Although I've never personally executed them, a compression test and leak down test would probably verify the head gasket condition.

When you said you changed the plugs, what did the old ones look like? They can often tell the story about what's happening in the combustion chamber.