Electrical Tachometer Over Reads Rpms

Discussion in '2.3L (N/A & Turbo) Tech' started by Dalfrarron, Nov 27, 2013.

  1. hey guys i'm new to this site but been around the repair club for quite some time. i have a 92 2.3 lx coupe. my rpm gauge jumps to 3,000 rpm when car is started. wont move till i get it above that. still seems like its working just fine. drops to zero when car is off but does jump up to 1,500 when ignition is on. I have replaced the crank shaft positioning sensor, and ICM with no luck. randomly the car will just shut itself off almost like it stalled out. im pretty sure ive narrowed it down to my computer but i would like to see if anyone has solved this problem since i cant seem to find anybody that has actually fixed it:( i can drive it if im slow and easy on the throttle but as soon as i floor it sputters and backfires. randomly my airbag light comes on too. ive pulled codes 222 and 223. pretty sure all my coil packs are fine and spark plugs are good. will double check tonight. so far only thing i can find on this is that my tachometer is bad but i dont see how that could be when it still moves just fine. any feedback would be much apperciated. previous owner drove it around in safe mode with a bad icm and who knows what else. no vacuum leaks........... im just lost and dont wanna drop more money into this thing yet. already down 300 from just the other sensors.
    can post pics and videos if anybody needs me too

  2. I have had this issue twice with my car. In May '12 it was the ICM but in '05 or '06 the wiring harness for the O2 sensor actually fell onto the header and fried - that being said, I have an aftermarket header and the harness was lengthened and re-routed so this may not be your problem but I thought I'd throw it out there.
    You say you're "pretty sure" your coil packs and plugs are in good working order; the coil packs are about $100 for both, but checking and replacing the plugs might be worth the $30.
    Google shows this problem is pretty prevalent but a new ICM usually fixes it. Can you get your ICM (both old & new) tested at your local auto parts store? How about the coil packs?
    Also codes 222 & 223 are listed below.
    222 C Loss of Ignition Diagnostic Monitor (1DM) signal-right side
    223 C Loss of Dual Plug Inhibit (DPI) control
  3. so i haven't gotten the chance to test my coils and check my plugs but i did take her around the block the other day (maybe 3 miles) and its running really funky. i have to slowly creep her up from 2,000 to 3,500 before she actually runs like its got power. it didn't wanna shift into my 4th od gear either until i backed off the gas. exhaust smells like unburnt fuel. i no longer have any codes but im not sure if the car ran long enough for the computer to pick them up and my tach is still stuck. i can get my sensors tested just not sure when (i work ALOT). i have two old ones that i know were bad from the tests but never bothered to check the new one....you know since its new but it wouldnt be the first time i got bad new parts lol. ill take a look at my 02 sensor. i believe it does need a new cat but im to broke to afford one right now. to many projects and this one is close to last on the list but would love to take it off the list!!! ill be able to really tear into her this weekend so ill post anything i find or if im still having problems
  4. 3 miles should be long enough to trigger the Check Engine light. When I had this problem the light would go on & off at will, much the way the car drove normal and then suddenly felt like it was misfiring and then back to normal.
  5. so all my coils are good and im getting spark to all my plugs. pulled all plugs and they looked fine. could a clogged cat make the car studder on hard acceleration?? also the tach is still messed up but it seems car revs up just fine now havn't got another check engine light yet. im replacing the wheel bearing asap then ill leave more feedback on how she drives. if i unbolt the exhaust right after the headers and run it would that bypass the whole cat issues??? or at least can i do this to make sure its a clogged cat??? i have a brand new EGR valve on it to but i noticed that its making a ticking noiseat idle like the rubber diaphragm isnt seating or staying shut like it should. ive had problems with egr system before so i know everything you can know about them. could this be an effect of the clogged cat or just something in my egr circuit. any help is much appreciated

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  6. I don't remember, off-hand, where the O2 sensor is on a stock exhaust system. BUT I believe there is only 1 and it is pre-cat. If you take your exhaust off after the sensor and before the cat you should have your answer about whether or not it's your cat.
    I'm not trying to sound like a smart-ass but if you know everything about the EGR system you should be able to figure that out without much effort. Possibly just a bad part?
  7. your right where the 02 sensor is bad. i use to have an explorer with tons of EGR problems so i know everything in an EGR system. just not the best at figuring out what the problem is. just wanted to make sure this test would work. so if it still runs :poo:ty i probably have a bad 02 sensor. Everything could be stock besides the EGR i know thats new so it might be time to change the 02 sensor too lol. Thanks man i just like input on these kind of things before i go and start ripping the car apart. to many projects so time is valuable to me
  8. sensor is, it could be bad*
  9. Haha I understand!
  10. so my tachometer is probably just broken since its still messed up and all the Components that control it are good. unbolted the exhaust right after the headers this weekend and fired her up. sounds mean as **** for a 4 cylinder but the best part is it revs up just fine so i do have a clogged cat. does anybody know of a good aftermarket cat that will still pass emissions in cali?? want to keep this thing sounding the way it does now if there is anyway possible besides making my stock exhaust pass smog then taking it off for another one.
  11. I'm not familiar with CA emissions so I'd recommend a stock replacement.
    By saying "keep this thing sounding the way it does now" do you mean how it sounds with the exhaust disconnected after the header? It's going to take more than an aftermarket catalytic convertor to do that.