89 Ranger 2.3 miss and shows half the rpms on tach.

[1bad87five0ranger]

I have been having a problem with my truck for quite sometime. The truck used to pull very hard and have lots of power for a 2.3 it surprised me when i bought it. I started driving it daily and one day i was driving and the tach started jumping around and the truck would missfire with the fluctuation of the tach. It later stopped working completely. I found a broken wire to the plug on the coil pack on the drivers side of the engine. I fixed the broken wire and i started the truck up and now its showing half the rpm that the truck is actually at. It also seems like it doesn't have any pull to it at higher rpm. I'm not sure where to look now. I don't really understand the dis system and how the tach plays a role but i do know everything goes through the dis module and i have replaced it also. I get poor fuel mileage and still have a misfire at idle and a hesitation under acceleration. I would like any info someone could give on this subject thanks

 

[Haywire6000]

More than likely the Ignition Control Module. I had this issue with my '93 mine would only do it on super hot days at first, finally just started doing it all the time.

 

[1bad87five0ranger]

i just put a new one on it. It works consistently at half the rpms.

 

[Earl43P]

http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_Ignitionsystem_1989_2_3.JPG

Here is a diagram of your ignition system.

 

[stuntsunltd.]

coil packs

Check the tech library here for information on how to test your coil packs... sounds like one of them has or is dying.

 

[cammeddrz]

the tach reads pulses from the ignition coil as rpm. it pulses 2 times for every revolution of the crankshaft. if the coil isn't getting a connection/signal to discharge spark it will cause a mis-fire,

and the fact that it isn't discharging spark means that the tach is getting less signals to interpret as RPM. i.e. reflecting lower RPM

i'm going to go out and pop the hood on my 1993 2.3 and see if I am remembering this correctly

**edit, it looks like it has 2 coils, i would bet money one of the two coils has failed. half as many coils sparking= half the RPM on the tach

 

[1bad87five0ranger]

i just replaced coil packs and am still having the same issue. I checked codes and it said tach signal lost and spout circuit open or grounded. Any ideas? It starts every time, never stalls out on me but it lugs really bad and started doing it when my tach started reading low. it is killing me on gas i really need to get this fixed. I have checked wiring and have found nothing out of the ordinary.

 

[1bad87five0ranger]

Ok i finally did a koeo test and i got codes 18 and 98. can someone point me in the right direction with this one?

 

[SenorNoob]

I'm not sure where to point you other than this: http://www.therangerstation.com/tech_library/2digitcodes.html