91 dodge truck 318 misfires

Ford coil on plug systems are multi strike ignition (spark) under 1300 rpm then go to single strike a single cylinder misfire can be created by several things . #1 Test engine compression on a cranking engine compression it should be around 150 lbs but if gauge reads different COMPARE to other cylinders that work fine #2 check engine running compression this will be around 120 lbs then rev over 2000 rpm and check pressure drop again COMPARE to other cylinders that work fine. any drop would indicate valve train problems. #3 All internal engine is fine then external problems are present vacuum leaks and or fuel injection volume is low.

Your caption says misfires at high, then you say low? You have a 95. Lots of miles I assume. So there are several things that would cause misfires at high and low. First is timing chain/belt, sloppy. Second, would be the valves and rings. Valves worn or bent, not seating right. rings just worn out, not holding compression. Do a compression test and see. Low speed or idle misfires can be from vacuum leaks. check hoses. Low and high rpm misfires can be from ignition problems. Wiring, coil/s, ignition modules.

U definitely do have a thermal issue with the traits you have described. The diagnosis you got is spot on. But shop around for the part since most places will not allow the return of electronic parts.

yes as will a cracked distributer cap, and a bad coil will only fire when it decides to having a nomiss nomiss miss nomiss situation.

Check out related help links to troubleshoot these problem:----Click the link below:---Idles Fine but RPM jumps in drive mode? http://technoanswers.blogspot.in/2012/07/idles-fine-but-rpm-jumps-in-drive-mode.html
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http://schematicsdiagram.blogspot.com/2011/12/how-to-adjust-rpm-on-2009-dodge-charger.html
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Cold start problem and vehicle shudder around 2500 to 3500 rpms
http://repairhelpcenter.blogspot.com/2012/10/cold-start-problem-and-vehicle-shudder.html

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These will help.
Thanks.

Check out related help links to troubleshoot these problem:----Click the link below:---Idles Fine but RPM jumps in drive mode?http://technoanswers.blogspot.in/2012/07/idles-fine-but-rpm-jumps-in-drive-mode.html
---------Mitsubishi Lancer rpm needle bounces?http://technoanswers.blogspot.in/2012/02/mitsubishi-lancer-rpm-needle-bounces.html
--------How to adjust rpm on 2009 dodge charger SRT8?

http://schematicsdiagram.blogspot.com/2011/12/how-to-adjust-rpm-on-2009-dodge-charger.html
---------
Engine cuts out at 3000 RPM?http://schematicsdiagram.blogspot.com/2011/12/engine-cuts-out-at-3000-rpm.html

---------

Cold start problem and vehicle shudder around 2500 to 3500 rpms
http://repairhelpcenter.blogspot.com/2012/10/cold-start-problem-and-vehicle-shudder.html

---------
High rpm in neutral? Inconsistant high RPM in neutral?http://technoanswers.blogspot.in/2012/02/high-rpm-in-neutral-inconsistant-high.html

-----------
Jetski Sputters and Low RPM? http://whatisbyme.blogspot.in/2012/07/jetski-sputters-and-low-rpm.html

--------
Fuel Injection Problem And RPM suddenly increaseshttp://whatisbyme.blogspot.in/2012/07/fuel-injection-problem-and-rpm-suddenly.html

----------
2005 Toyota Highlander: Engine runs hard RPM below 3000?http://whatisbyme.blogspot.in/2012/05/2005-toyota-highlander-engine-runs-hard.html

---------
1987 Toyota Camry: RPM Drops going Up hills?http://whatisbyme.blogspot.in/2012/05/1987-toyota-camry-rpm-drops-going-up.html

-----------
Cruise Control stops working, Excessive cranks to start the engine and RPM goes max 2500 http://whoisbyme.blogspot.in/2012/07/cruise-control-stops-workingexcessive.html

----------
1990 Toyota 4Runner: Engine cuts off when reaches 2000 RPM?

http://whatisbyme.blogspot.in/2012/05/1990-toyota-4runner-engine-cuts-off.html

------------
1999 Toyota Camry: Erratic stalling and high engine RPM at idle?

http://whatisbyme.blogspot.in/2012/05/1999-toyota-camry-erratic-stalling-and.html

---------
1995 Toyota LS: Misfire at idle or low RPMhttp://whatisbyme.blogspot.in/2012/04/1995-toyota-ls-misfire-at-idle-or-low.html

-----------
Lexus RX: Tapping noise under Valve Cover At Low RPM?http://technoanswers.blogspot.in/2012/04/lexus-rx-tapping-noise-under-valve.html

----------
These will help.
Thanks.

could be a catalytic converter or o2 sensor. really would need to hook it up to a proper scan tool to view live data while running.

intake gasket blown

Good Day Tony,

That's an intersting problem.... I would assume that if it was misfiring in a cylinder it would trip your check engine light as it did before. Because it only happens when you are going 50 it might be something else. What happens when you put the truck in park or nuetral and rev up the engine? Rev it up slowly and see if jerks or hesitates at any particular rpm range, I'm just trying to rule out if it's a possible transmission problem or engine problem. Let me know and I can assist further.

Good Luck