Ping/Backfire When Accerlating

1986 olds 3.8 w/ 120k

New: o2 sensor, MAF sensor, coils, Alternator, rubber vacuum hoses, air filter, fuel filter, plugs (non-bosch), wires (really cheap ones though), PVC valve/hose, fresh 87 octane fuel

The engine runs well at idle, but when I accelerate i hear a pinging noise from my exhaust and it backfires when i try to greatly accelerate.

I've done some research over the internet and I've found several possibilities as to what may be causing my backfire. I thought I'd bounce some ideas off you very knowledgeable people and see what ya'll think.

Possibilites:

-Bad plug wires
-exhaust leak
-clogged fuel line
-vacuum leak/bad canister
-timing off
-needs new 180* thermostat
-EGR valve (Edited In)

If it helps any, the car sometimes has a strange fuel-odor after shutting down the engine.

Thanks for any ideas in advance!

I would change the plug wires as they are probably bad. As for the backfiring you may have a burnt valve causing this. Do a compression test on the engine to see if you are getting proper compression on all cylinders, if one is low that is probably causing your problem. If it is a burnt valve then you are looking at removing the head and replacing the valve.

As for the fuel odor check for leaks on the fuel rail and you may have to replace the fuel pressure regulator as they will leak if they are going bad. This too can cause poor acceleration but shouldn't cause a backfire.

OK, thank you very much. I'll try the fuel pressure regulator and the wires this week and I'll go from there.

One more thing I found today though is that I'm running a stored code 32...but my chilton's doesn't include 32 in their listing. Anybody know what it is?

OK, I just got back from Autozone. I bought non-bosch plug wires and I'm goning to install them tonight after the engine cools off a bit.

I found out that a code 32 is for the EGR valve...but the guy at Autozone said that it may be possible to remove it and clean it up.

Know of any ways to clean it? Are there any ways to clean the fuel pressure regulator?

And I just noticed that I have a misspell in my topic...

You can't do anything about the fuel pressure regulator, if it is bad it must be replaced. As for the EGR you can clean the passageways to the engine using throttle body cleaner. Sometimes they are the culprit as the blockage causes the EGR to not function properly. As for the valve itself, you can spray the areas exposed to exhaust gasses with the cleaner but if it is electrical in nature there is no way to fix it. It is quite possible that the EGR is causing the majority of your problems too!!!

have you checked your exhaust gaskets???

I installed my plug wires today and boy did that engine like them. It started up on the first try and It wasn't idling running as rough or pinging out the tailpipe hardly any.

It still backfires just a little bit when I put a load on the engine so i'm going to try to clean the EGR. I looked at it today while I was replacing the wires...umm...how do you get it off to clean it? I dont see any screws or bolts holding it in...that or I'm just blind.

Also, is throttle body cleaner and carb cleaner the same stuff for cleaning it?

I checked the fuel pressure regulator and it doesn't seem to be leaking. The fuel smell might have just been a by-product of the plugs firing bad? It hasn't smelt funny since I replaced them but then again I've only gone to Wal-Mart and back.

I haven't checked my gaskets, but wouldn't the backfire or some kind of rumble noise be constant if the exhaust gaskets were worn?

Ok, I pulled my EGR valve off and cleaned it out. No more funny fuel smell and the engine seems to have more power.

However, the backfire is still present. How would I do a compression test?

I really doubt that there is an exhaust leak since it backfires only when accelerating or under a load.

Also, would a bad IAC valve do anything to make it backfire? I'm just really trying to avoid more expenses since I am poor :( .

Looks like I'm down to a vacuum leak, burnt valve, or the timing is off. Anyone have any more suggestions before I consider taking it to a shop (after i get paid).

Rent a compression tester and remove all the plugs. Once you have them out screw the tester into the hole and turn the engine over several times. When the guage stops climbing record the reading. Do this on each cylinder. You should see some variation but if you get huge drop on one cylinder like 0 then you have found a problem with a burnt valve or piston.

Ok. Sounds interesting. Do you think Autozone rents them?

I think so. If not try a tool rental place in your area most of them rent automotive tools!

Does anyone think it could be the TPS or the knock sensor? Both these control timing.

Ok, here is a recap.

new spark plug wires-no more ping
clean EGR-no more fuel smell
new filter-catch clogs

I did some more work on it the past few days. I removed my throttle body and thoughly cleaned it with carb cleaner. I also removed the IAC valve and cleaned it (had lots of carbon build-up on it). I then started the engine and dumped a can of Seafoam into the PVC valve hole. I neglected to read the part of the instructions that read to only pour in 1/3 of the can so I spent the better part of an hour keeping my car in idle and barely pushing the gas pedal to burn off some of the extra.

After i finally got enough of the extra seafoam off, I drove the car around the parking lot untill i was sure it wasn't going to stall before I went to get some gas.

My car actually has power now! It accelerates almost normally but it is still backfiring out the exhaust. I haven't ran it past 45mph yet, but I'm sure It'll still backfire.

So what does this point to?

-burnt valve
-bad TPS or knock sensor
-Exhaust leak
-thermostat
-other?

I just got paid today so I hope I can get this squared away before long. My next plan of action is to replace the battery cables (bought 'em today) and then get a compression test. Thanks for all the help so far!