1997 Dodge Ram skipping

BRIAN HOLDEN

MEMBER
1997 DODGE RAM
V8
4WD
AUTOMATIC
145,000 MILES

My 97 doge 318 runs good but skips under a pull at around 3000 rpm. I have already chamged plugs wires cap and button and the ecm. The code it gives is clyinder #8 missfire. When we ran the compression test #8 shot gas out to the fender. This happened before the ecm was replaced. It also gives the code of emission system incorrect flow detected everynow an then. What could my problem be? When gas is pressed harder such as going up a hill, the vacuum supply for the inside vents is taken away but comes back when throttle is settled back down.

5 Replies

JACOBANDNICKOLAS

MECHANIC
109,740 POSTS

If you loose vacuum to the HVAC system under a load, you have a vacuum leak or low compression which you already checked. Have you checked for vacuum leaks? Also, have you checked the catalytic converter for plugging? Also, does the #8 cylender always come up when the light comes on?

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Monday, April 12th, 2010 AT 8:34 PM

BRIAN HOLDEN

MEMBER
3 POSTS

I have checked for vacuum leaks and found only one under the intake coming out the valve cover but was told it was not bad. The convertor was changed when problem occured also. Yes it is always the #8 cylinder

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Tuesday, April 13th, 2010 AT 10:36 AM

JACOBANDNICKOLAS

MECHANIC
109,740 POSTS

If the compression is good, timing is right, fuel is there, and a "good" spark is present, there is nothing left. It has to be either a weak spark or it's not getting the right amount of fuel.

Did you repair the vacuum leak you had? A vacuum leak could cause the engine to run lean and miss.

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Tuesday, April 13th, 2010 AT 12:20 PM

BRIAN HOLDEN

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3 POSTS

Intake has not been fixed yet but it shot fuel out of #8 when we ran the compression test. Could the coil cause only one cylinder to skip?

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Tuesday, April 13th, 2010 AT 7:12 PM

JACOBANDNICKOLAS

MECHANIC
109,740 POSTS

Usually if a coil is bad, you will have a random misfire on multiple cylenders. I do remember you saying that it shot gas from that cylender. If you remove the plug, what does it look like? I'm questioning if the old plug fouled, wasn't burning any gas, and then you checked it after it filled up.

Let me know.
Joe