need help with backfiring prob

[sbro98]

My '99 4-banger ranger stalls and backfires when foot is on gas. Changed the crankshaft positioning sensor based on engine code P0320. Also replaced fuel filter but vehicle still runs bad. The fella at autozone said truck won't run better until codes reset by traveling a bunch of miles. But it's nearly impossible to drive a stalling and backfiring vehicle for more than a block. Any insight would be appreciated. thks, steve

 

[Shran]

I'm not really sure what to tell you as far as what your problem actually is, but I can tell you that the guy at AutoZone is dead wrong. If it is still throwing codes and not running right, something else needs to be fixed.

 

[sbro98]

I told the AZ guy the same thing but he insisted the error code would override the new part. Gotta have a PHD to navigate all these electro gizmos. At least it's not a toyota ranger.

 

[Twisted_Steel]

I agree with Shan... that AZ guy is full of shit. When the new/right part goes on, it's fixed, end of story. Have you changed your wires lately? If so, any chance they might be crossed? Check to see if one has come loose or is arcing. Do this in the dark so it's easier to see any errant spark. Another thing... have you put any gas in your truck from a gas can?... if so, possible moisture contamination.

Good luck!

 

[sbro98]

Have not messed with the wires but contaminated gas is a possibility. The truck is parked in an alley where vehicles have been known to be keyed, stolen and vandalized. I suggested to my wife some yahoo might have spiked the gas tank with water but didn't wanta sound paranoid.

thks for the suggestions

 

[Mark_88]

Backfire can be caused by several things...but bad timing is one of the most obvious...here is the short list if you haven't checked them already...

* Poor or unregulated engine timing is often a cause of intake backfires, but can also be responsible for exhaust backfires
* Improper wiring in the ignition can also lead to timing issues and backfires
* Low fuel pressure, clogged fuel filters, and weak fuel pumps could cause a severe lean air-to-fuel ratio during fuel injection
* Missing or damaged catalytic converter can result in backfires out the tailpipe

 

[sbro98]

Would any of these problems show up on computer codes? I changed the crank position sensor because of engine code P0320. Truck idles OK but stalls and backfires when gassed. appreciate the help

* Poor or unregulated engine timing is often a cause of intake backfires, but can also be responsible for exhaust backfires
* Improper wiring in the ignition can also lead to timing issues and backfires
* Low fuel pressure, clogged fuel filters (REPLACED), and weak fuel pumps could cause a severe lean air-to-fuel ratio during fuel injection
* Missing or damaged catalytic converter can result in backfires out the tailpipe

 

[Boghog1]

they should be able to erase the code, when was the last time you had a tune up done? how many miles are on the truck?

 

[pyro29123]

have you noticed a rotten egg smell in or around your truck? if so itsa prolly your catalytic converter

 

[adsm08]

A misfire code is the only one I know of that will continue to cause a problem after it has been fixed because it will shut down the injector to protect the cats. You gotta cleear the code to tell it the problem has been fixed.

Have you checked your CKP sensor's air gap? That could cause your problem. A bad wire could also do it.

 

[kimcrwbr1]

disconnect the battery for 1/2 hour to reset the values whenever you change any emission sensor if you have not done so yet. and put some heet in the fuel tank or some B12 injector cleaner then if you can run it for another good warm up and retest.

 

[sloth69mustang]

you dont need a phd to run those tools. they are actually really really easy to run. if you played with it for about 20 mins you would have the whole thing figured out lol

 

[adsm08]

Yeah, but you can't be a total moron for that. It seems to be almost a job requirement to be an Autozoner. Every time I go in there I answer 3 or 4 customer questions that they can't.

I'm gonna start charging a consulting fee.

 

[sloth69mustang]

Yeah, but you can't be a total moron for that. It seems to be almost a job requirement to be an Autozoner. Every time I go in there I answer 3 or 4 customer questions that they can't.

I'm gonna start charging a consulting fee.

+1 i do the same thing almost every time i set food in a parts store. esp AZ

 

[sbro98]

gratus guys, will apply your suggestions and report back. truck has about 90K miles and starts on first turn even in the teens. thks again