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.




Hi: A stuck EGR valve can cause the type of problems you described. Remove it and make sure it is functioning properly and there is no carbon build-up under it.

Let me know what you find.

Joe

I checked EGR and it is working properly. What it be now? I should mention that when it backfires, it is backfiring through the intake. Since I posted the original question the idle quality has gotten worse. And the hesitation is around 2,000rpm's. If you could point me in the right direction it would be great.

Tiny
Tanddracing
Dec 14, 2008.
Hi Again: You could try the O2 sensor, but it could also deal with the map sensor, knock sensor. I hate to say it, but you may have to take it to a mechanic, or you will end up replacing part after part until you hit the right one. It may get expensive.

Hello, I have replaced the O2 sensor and the map sensor along with a new throttle position sensor. The truck idles now and starts great, but when you mash the gas it spits and sputters and backfires through the intake. If you give it steady acceleration it will run fine right up to the limiter. Any ideas? The sooner you can get back to me the better as this is going to be my only form of transportation soon. I appreciate your time and your insight.
AD

Tiny
Tanddracing
Dec 26, 2008.
Ok: This is a tough one. Have you checked for vacuum leaks? Also, make sure the throttle body is tight to the intake.

As far as email, I'm on the site at least once a day to check mail, so I'm here for your questions and responses. If you're on tonight, I'll be here for about another hour. It's 8: 00 in Pittsburgh.

Joe

Hello, I checked for vacuum leaks and I replaced the gasket under the throttle body. I noticed when I started it this morning it idled rough, like it was loading up, sounded like it had a oversized cam(lopey). I live in iowa and the weather was cold and damp this morning. After running for a minute it smoothed out. I'm at a lost, and anything you can give me would be a great help. Could it be the cam position sensor? Maybe fuel pressure regulator, fuelpump? Maybe a bad injector? I checked for codes and there are none. HELP!

Tiny
Tanddracing
Dec 27, 2008.
I would tend to feel that an injector would be all of the time. It wouldn't hurt to check the fuel pressure. You can rent a tool at most nationally recognized parts stores. Also, it could even be a weak coil.

I hate throwing all this at you because I can't be 100% sure, and I don't want you to spend money on parts that don't need replaced.

I'm going to email this problem to a friend that is a tech here. He worked for a chrysler / jeep dealership and is a great mechanic. Let me see if he has ideas.

Joe

Let me ask when was the last time a complete tune-up was done meaning plugs, cap, rotor, wires also having timming checked

Jnovack
Dec 27, 2008.
I replaced the plugs, wires, cap and rotor about a year ago. I don't put alot a miles on it, I'm guessing around 10-15 thousand, never checked timing.

Tiny
Tanddracing
Dec 31, 2008.
Ok now pull distributor cap off and have someone crank engine and see if rotor turns if so the check ingition module on bottom of distributor

Jnovack
Dec 31, 2008.

AD