my 13b backfires after 30 seconds from starting the engine, it has a 10 second interval. I only upgraded the fuel pump, 3" exhaust, FPR and to an 8.5mm msd wires. Whats wrong with it? PLease HElp!!!

 

Spark plugs?

 

backfire? like a giant flame pops out the back? lol, if so get used to it. The n/a cars ran rich from factory, and the un burnt fuel in the exhaust get ignited there and causes a giant flame. =)

 

might be running rich ?due to the new pump. but making flames isnt so bad im used to mine lol.

 

also your exhaust piping could be too big.

 

Umm anyone else notice it sounds like it's doing it at idle...yeah that's not good but will make for some good burnt dogs running around the backyard here lol...

 

Do you have any sort of fuel controller to go with your upgraded pump? It probably running retarded rich, especially if its shooting flames AT IDLE!

 

So... what exactly did you upgrade the pump & FPR to? And do you know what kind of fuel pressure you're running at idle?

My bet is that even if the FPR can flow the needed capacity, the return lines to the tank can't handle it. If you put a fuel pressure gauge in, I'd place money that you're running significantly higher than spec pressure at idle.

-=Russ=-

 

What about a back fire when trying to start. The car isnt running at the moment but when it trys to start i get a big bang. any takers?

Tommy

 

Holy necro batman!

 

check the order of the plug wires.
sounds like you got the trailing wires backwards.