mike703

Car 2007 si 118k
The car has been sitting not being used since saturday night.
Outdoor temp below freezing.
I go out to start the car this morning and it wont start.
I checked the oil and the coolant all is good.
Plugs have been changed within the last 12k
So i start cranking it again and it still wont start, so i stop then crank it again this time pushing on the accelerator pedal just for *****, and then the intake box literally exploded and blew all the tabs off and the filter out of the engine compartment. This is the first time ive ever seen an intake explode during a no start. Car ran absolutely fine prior to this.
Anyone know what it could possibly be?

97emsedan

Sounds like a backfire that ignited fuel in the intake mani...

None2Slow

I wonder if the no start was from lack of air, yet the injectors were still pumping. Then, when he opened the throttle body, this let air in and all the fuel that puddled in the cylinders got spark. Maybe the throttlebody was sealed from the cold. I had an old carburated V8 car that would just crank and crank. When I jumped it, it fired right off and blew both mufflers apart. Bad ignition module was the problem. Maybe you have something similar going on.

97emsedan

TPS sensor is known to be problematic... I had mine replaced twice before the car became worry free. The sensor might not give the correct reading and the ECU might respond with more or less fuel and such...just a hunch...

mike703

sorry for the delayed response.
Today i check the wiring to the CKP sensor and it checked out fine.
I also checked the relay for the ignition and it was fine as well.
I will check the TPS tomorrow morning and report back.
The backfire was a one time deal as it hasnt happened since, so i believe none2slow is correct in what caused my backfire.
I also looked for ways to check the CMP and CKP sensors themselves but all diagnostics i can find are for the wiring leading to the sensors and not the actual sensors themselves.

Deksinjo

Hey man, are you at 8th gen. 07taffyfa5 ?

HiProfile

Pumping the throttle on a fuel injected motor is pointless. For old cars that was a form of manual fuel enrichment like pushing the primer on a lawnmower. Your Civic won't respond the same way.

Another reason for intake backfire is a slightly open valve at ignition. It would also develope low compression for that cylinder and not have much power, which can also cause hard starting.


If all else fails, spray some starter fluid into the intake (5-10 sec shot), then crank it a few times to see if it does anything. It had fuel before, so it's possible it's now flooded which will foul the plugs. Starter fluid will allow almost any engine to start if it has spark.

None2Slow

Correect in that the puming the throttle has no effect on supplying fuel. However, carbon buildup around the throttle blade will restrict airflow in the idle position and not allow air in. This can cause it to not start until you open the throttle blade. Not sure about hondas, but on Fords it is a somewhat common problem. It builds up, holding the throttle blade open just enough to tell the tps that it is open and to "turn off" the Idle Air Control (IAC) valve. By doing this, there is not air at start up and the car wont idle. I have seen the dealer not catch this on my personal vehicle.