Mechanics

HARD STARTING/MISS/BACKFIRE

1992 Dodge Dakota

Engine Performance problem
1992 Dodge Dakota 6 cyl Two Wheel Drive Automatic 249986 miles

This is an intermittent problem, sometimes it starts hard and once started it misses and won't idle. Also, at times it misses and stumbles and backfires under acceleration or at speeds around 65-70. I checked for codes and came up with O2 sensor and egr codes(12, 21, 32) I suspect it is the crank position sensor, but I'm unsure and would like your input. Thanks
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Tanddracing
December 7, 2008.




I don't understand where you are going here? The truck starts and runs. It has a hesition now or a flat spot in the acceleration. With steady pressure on the gas pedal it will run ok. You mash down on the gas and there is a dead spot and it starts to pop and bang, spit and sputter. And will die if you don't let back up on gas.

Tiny
Tanddracing
Jan 1, 2009.
Ok do a compression test and let us know what you get on all cylinders and your code 21 TPS voltage was above 2.5 volts for 8 seconds when the MAP sensor signal showed manifold vacuum to be 15 pounds or more. and the code 32 EGR open command did not change the fuel mixture when the command was given during off idle operation. EGR opening should cause the mixture to be slightly richer because of the low oxygen content of exhaust gas. but do compression test also check the firing order is as follows
Firing order 1-6-5-4-3-2

| 2 4 6 |
front | |
| |
| | 1 ||
| |2 6||
of | |3 5||
| | 4 ||
| |
vehicle | |
| 1 3 5 |

Distributor rotates clockwise
Inspect the ignition coil for arcing while the engine is running. If the engine will not start, this can be performed while the engine is cranked by either an assistant or a remote starter. Look at the coil in dim or low light to aid visibility of any arcing.
Arcing at the tower will carbonize the wire boot, which, if it is connected to a new ignition coil, will cause the coil to fail. In such cases, clean all the carbonization away or replace the components as necessary.


http://www.2carpros.com/forum/automotive_pictures/52960_0900c152800706b2_1.jpg


Jnovack
Jan 1, 2009.
I check compression and everything is alright there. All cylinders had 90-95, and the ignition is wired correctly and as far as coil, everything looks good, didn't check resistance. I also, checked fuel pressure and with ignition in " on" position it had 15psi and with running it had 20psi, but the needle bounced around between 19.5-20.5psi, also when I hit the throttle it dropped to 15psi. And I should also mention that the pressure would drop down to 5-10psi after the engine was shut off and was sitting for a minute or two.
AD

Tiny
Tanddracing
Jan 4, 2009.
Fuel pressure should be 37-41 PSI(Pounds per Square Inch) compression should be 100 psi +or- 8% 92 min. And 108 max. I would look into checking the fuel filter and or pump

Jnovack
Jan 5, 2009.

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