Hey Folks........

Have just stumbled across this forum, and am hoping for some good advice from fellow Mitsu Owners. I have had this problem for a few years now and now and again dust off the Tech Manuals and try to find and fix the issue and to date have had no joy....... hopefully some good advice will come from this post

My PJ is a 1995 FTO GR, D38A (V type 6 cylinder DOHC 24 valve same as 97 gallant)I have owned her from the day she was Imported from Japan to Ireland 8 years ago now, (now living in UK) about 6 years ago I have a problem with the car not starting and had the CAS changed when I got the car back the Tacho was not working.

The following is what has been done to date:

Inspection procedure 54-15 (no codes from ECU(OK), all wiring checks at gauges to +/- and ecu and sensors (OK) the Tacho feed says it should be 5v and am only getting 4.6v (??) ... outcome says change Tacho which I did and ....still not working.......

IFS (Ignition failure sensor) Change ....still not working.......

ECU SWAP ....still not working.......

I have a UNI-T Auto Meter which has 6cyl rpm signal test but can’t get any signal from the ECU signal wire, speed connection wire or the IFS or engine speed connector......


Jay

PS have all workshop manuals for this Engine in PDF format if they are any good anyone ..

the engine is a 6A12 and its the same as a 1992-1995.5 Galant , not 1997. Did yu check the power transistor? Its hard to say . Did anyone check to see if the fuel pump and fuel system is operating. Is there ignition firing at the leads? An ECU failure will cause a failure in the ignition system. An issue with a bad power transistor will cause problems with the tachometer .

Spot on 'KiT TeUnG 2549' My error ... how do i check power transistor ?? will the fuel pump and fuel system cause this prob the car is running brill and nno code out of ECU ??

so the car is running , juss the tachometer is not operating?

Yeah sorry my first post was not that clear ...... Yeah car is running fine, its only the tach that is not working

Hey 'KiT TeUnG 2549' thanks for the replys good to have your feed back you sure know your stuff good to get your advice after a bit of research is the PTU is this the same as the ignition failure sensor ???? if so its been checked and changed. Would the fact that i am only getting 4.6v when i check the tach feed at the the gauges (harnis side) it say in tech manulas feed should be 5v while power on and running .....(it is ment to be a 5v square wave feed ???)

Cheers

Jay

Are yu juss having an issue with yur tachometer ? The car runs? Well 4.6 is an acceptable alot juss round up. Ive seen 4.3-5.1 usually present in these systems. Sumtimes it depends on the multimeter. The tachometer works in this manner. Depending the system. Most tachs on gauges , depending model , as in my Diamate which has High Contrast gauges with HUD there is a 12v input and a Ground input and the reference signal frum the power transistor . The power transistor reference is a varied sorta "grounding" signal sent via the power transistor.


Think of it this way , as the power transistor is wut applies a referance to make the ignition coil spark. The ignition coil "pulses" via the signal the power transistor sends. So it can make each cylinder fire when should. The Tachometer is the same way as the coil. Juss like the ignition coil , the tach is grounded , and also has a 5-12v signal applied at ignition on and then the referance signal via ( in this case) the power transistor makes a very low V signal to operate the coil and tachometer.

At the wire harness yu cannot check the signal to the tachometer unless the vehicle is running. Yu can check the voltage and ground but not the signal, which will range in very low frequency.

Yeah KiT TeUnG just the Tach is giving problems car runs fine ..... have tested the tach feed harnis side with car running and as said only getting 4.6v but that should be fine, also checked earth and live to gauges and continuity from gauges to IFS and ECU and also fine...... its the power transistor you mention the same as an IFS as in att diagram A65???? or is it part of the coil in the fto??? this IFS unit in diagram has been changed for a new unit did not fix the problem .....



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Is the PTU built into the coil pack as below, this also feeds the IFS so might trying new coil packs solve the problem????

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Well i think yur going about it all wrung. Yu see , its not that way. the referance signal sent to the tachometer is a pulse wave and varies thru teh rpm range via the signal. The more consistent the pulse the higher the tachometer needle will move. The tachometer gets a common 12v signal shared with other common inline things on the circuit board . They do not each all get individual 12v. For instance , most the bulbs and turbo meter and oil meter and tacho , and oil light and fuel warning light and 4WS lights , low traction light on a 1994 Galant VR4 SUPER INVECS , they all share the same 12v ignition on signal The Speedometer and Fuel gauge and coolant gauge all share the same 12v and ground . The digital odometer and tachometer shares the same ground. The tachometer referance will never be a constant 4.6v. That doesnt make sense. SO it seems yur testing it teh wrung way.


Yu may call it ignition failure sensor but we do not catalog it that way or refer to it that way. My catalogs , books all refer to it is a power transistor. ive put a photo of one off a 1995 Mitsubishi Galant SUPER VR4

so i guess, if its not the ECU, Tachometer, or the IFS (IFS) which have all be checked and changed and there are no codes being pulled out of the car it must be wiring somwhere (which all seems good) (IMG:style_emoticons/default/sad.gif) ...................

Thanks for all you advice its nice to find somone whos knows there stuff even the guys in Mitsubishi in London could not sort this out, what would you suggest from here ?

this is the one off fto gr 95

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The IFS in most sense has nothin to do with the tachometer reference signal. The way to check is more than one way. On the firewall there is an ignition timing referance plug and tachometer plug. They are usually capped. Its a light brown that will protrude frum the wire harness. One is for referencing the ignition timing while the brown capped one is for checking the engines RPM with an hand analog tachometer , so the rpm can be watched frum underhood while checkin the ignition timing.

This one plug in yu can check the ignition rpm referance. There can be simply an issue with the tachometer in the dash. A way to check would be hooking an analog tachometer. Is it a automatic or manual. The power transistor and IFS are different items

Have tested tach from under hood at speed connection plug at firewall with rpm meter and nothing, also have had the dash tacho re-placed also tested in another FTO so i know it works fine........

Yu kno one of those is an engine timing connection? Well okies yu are not having any signal even at teh test connection yu are saying? There is a problem at the Power transistor (not confused with Ignition Failure Sensor) . The IFS on many Galant models (turbo and 6G73 V6 equipped) as shown is integrated in the Power Transistor except sum lower non turbo models as in FTO (1996 up are integrated)

The power transistor is near the ignition coils on a seperate bracket. if yu are not receiving a signal at all it will lead to the Power Transistor. Or beak in wire at that point. The picture i submitted shows how the arrangement are listed.

Thanks for the info you were right it is a separate unit but the power transistor units are part of the coil units in the 95gr not a unit on its own, just removed them and did service check on units and all are working fine, checked harness between PTU , IFS and ECU and that’s fine too, but not getting any signal from PTU I think the signal has to be x3 cause there are 3 units one in each coil anyways look like I am back to square 1 …..With all this so far everything says the tach should be working but its just not… ….

So what we know so far the only parts in the tach circuit are PTU (intergraded into each coil), IFS, ECU, Gauge Pod, and wiring would that be right ???? Have att a diagram of what i thins flow of sys is !!! Am so so LOST on this one its doing my head in (IMG:style_emoticons/default/sad.gif) … is there any work around for this can we feed the tach signal from somewhere else or add a tach signal sender etc any ideas???

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O by the way I am using a digital tach multimeter (6 cyl) to chech for signals ??? you mention Analog Tester !!!!!

In DFS ignition coils, (the ones on yur car) as well as most GDI mitsubishi vehicles and lower voltage ignition firing systems , has the type of coil yu have. But the thing is that the signal isnt x3 and its not generated by the coils. Altho a pulse rate is generated by the coils in a sequence . Each time the coil first the signal is intersected. Like a 3 into 1. In a way the IFC will pick up the signal of each coil firing. And transfer it to a seemingly ECM signal as well as Tachometer signal. My thoughts on it.

I see many Galants 1992-1995 with a 6A12 or 6G73 but they use high Energy Ignition coils with a seperate power transistor. With the power transistor as i showed in the picture earlier post . Anyway the IFS merely reads when the coils are firing and sends the data to the ECU. So since its reading the firing rate of each coil it should also pick up the rate to which its firing , and send the signal to the Tachometer.

With a scanner , watching engine data , the ECU is signaling the coilsfiring. Heance via the TDC/crank sensor and cam signal , so it already knows dynamically wut the engines rpm is. But the RPM signal that is sent to the tachometer does not come frum the ECU.

Right so the ECU is not feeding the tach... the signal is transfered from the coils to the IFS and on to the tach?? yes you are right i think the ECU is getting the RPM from the crank angle sensor/cam sensor as when i plug laptop into OBDII and run EvoScan i can see thh rpm and coils firing sequence. So if the IFS is working fine and the coils are working fine it looks like could bs a wiring problem and is there is continuity between all the parts (no damaged cables or connectors)... could a bad ground or an Open circuit damaged connector??

Well i looked at yur diagram and i looked at my older Mitsubishi manual , which shows both yur schematic and also DFS (dual flow sensing) ignition coils with High Energy Ignition Coils. And it seems that the IFC directly feeds the Tachometer. Since it is not reading which coil is firing and when , it is just picking up the sequence pulse as each coil is firing in order and relates the signal to the ECU and also sends a pulse signal to the tachometer. hard to say , the IFS couls be working well in most respects but not sending a signal to the tachometer? Possibly yes , or short open lead , or bad grouning of the IFS

Cheers guess gonna have to strip and check ing sys harnnis will let you know the out come thanks for all the info and advice

Hope it gets sorted , good luck

Hey,,,

Just am update for you........ NO JOY with wiring , cant find anything wrong, well guess will just have to put up with this for another while thanks for all your help ..


Jay