Backfire in the intake?
03-07-2006, 07:28 AM
#1
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Join Date: May 2004
Posts: 128
Backfire in the intake?
My car is cranking and cranking with no start. When I let go of the key it kinda backfires in the intake and they it starts just fine.
It runs great after that with no problems. I dont have a CEL either. What is going on that makes that happen. Please help a brotha out.
It runs great after that with no problems. I dont have a CEL either. What is going on that makes that happen. Please help a brotha out.
03-07-2006, 04:25 PM
#4
Your motor is spitting fuel and spark during crank up...
If you let off the ignition, the motor is still spinning "forward" persay....
But it has a SLIGHT jerk, backward......forcing the fuel and spark (BACKFIIIIRE) back thru the intake manifold and out the intake.
Mine did the same thing.
Are you 5spd or auto?
What other issues do you have?
It could be a LONG list of problems, but not hard to find/diagnose.
If you let off the ignition, the motor is still spinning "forward" persay....
But it has a SLIGHT jerk, backward......forcing the fuel and spark (BACKFIIIIRE) back thru the intake manifold and out the intake.
Mine did the same thing.
Are you 5spd or auto?
What other issues do you have?
It could be a LONG list of problems, but not hard to find/diagnose.
03-07-2006, 05:19 PM
#5
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Originally Posted by texasluva
My car is cranking and cranking with no start.
When I let go of the key it kinda backfires in the intake and they it starts just fine.
When I let go of the key it kinda backfires in the intake and they it starts just fine.
03-08-2006, 04:02 AM
#10
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He's got a crank with no start until he lets go of the key, then it starts and runs.
Thats a faulty ignition switch. The reason it's gives a pop is because it's dumping fuel while he's cranking, but the faulty ignition switch has a bad contact, thus some part of the ignition isn't energized and he's plugs aren't firing. As soon as he lets go of the ignition switch, the contact is made and the plugs fire. There's his pop and the engine starts to run. The reason it pops is because the starter stops spinning the motor as the plugs start to fire. That timing of spark, plus the excess fuel, plus engine crank speed can cause a pop or slight backfire.
There's nothing wrong with the guys engine.
Thats a faulty ignition switch. The reason it's gives a pop is because it's dumping fuel while he's cranking, but the faulty ignition switch has a bad contact, thus some part of the ignition isn't energized and he's plugs aren't firing. As soon as he lets go of the ignition switch, the contact is made and the plugs fire. There's his pop and the engine starts to run. The reason it pops is because the starter stops spinning the motor as the plugs start to fire. That timing of spark, plus the excess fuel, plus engine crank speed can cause a pop or slight backfire.
There's nothing wrong with the guys engine.
03-09-2006, 05:40 AM
#11
100% chingon
Join Date: Oct 2005
Posts: 1,003
Originally Posted by NightRider
The only way for your intake to backfire is if you have bent valves. The intake valve has to be stuck open during the combustion stroke for flames to shoot out on the intake.
03-09-2006, 09:00 AM
#12
Senior Member
Thread Starter
Join Date: May 2004
Posts: 128
I have an automatic trans. You really think it is the ignition switch? could it really be that easy. Maybe I didnt state my prob well. it cranks and when I let off the key it backfires out of the exhaust.When I try to start it again after the backfire, and it starts fine. Why would it start fine after the backfire. what is the difference after the backfire than before. If it was the ignition switch wouldnt it backfire everytime i try to start it?
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