No fire coming from 1 and 4 cylinder 420a

[Moorejoey]

Ok guys I have a 98 eclipse gs 420a auto. I know not turbo but I love the 2g eclipse body styles, here my ? I bought the car cheap and the people I got it from said it died and was told it was the computer (pcm) so they got 1 from a wrecked eclipse not sure what year tho. it fires on 2 and 3 cylinder but not 1 and 4 no sprk from coil turmals. I know I cant spell sorry. iv changed cam and crank sencers and still no go. have checked the wires on the plug to coil it has 12.1 volts to black and red power wire and it has a pulse on the brown wire that fires 2 and 3 but heres the thing on the black wire with blue stripe it has consant power. some one please help.

 

[Cdc1221]

Don't make it so difficult. The coil is bad, so replace it

 

[Moorejoey]

I ment to put that in original post also have replced coil with a known good 1

 

[stealth406]

Have you tried the ignition control module, or "igniter"? Not sure of mitsubishi terminology but they're one in the same. This giving the wrong signal could make this happen. Also have you made sure all of your connections are tight and free of corossion? And finally since the ecu was from a junk car and unsure of the year you may still need an ecu or one from your year and auto trans. That may not be the the problem but it is worth looking into.

 

[Moorejoey]

Im thinking its the ecu to im going to use a buddys to see if that's the prob and I don't think the 420as have a igniter. Also there is no corrosion on any of the connections iv checked all them.

 

[ervin00]

Are you sure that you installed the CAS correctly? its easy to put it on 180 deg off.

 

[DSM_GSX01]

Crank or cam sensor i bet. My 420a. Had a bad cam sensor. Also look at your wires

 

[Moorejoey]

I put it back on with the plug facing then fire wall? and iv changed both the cam and crank sensors and still the same only fire on 2 and 3 cylinders im stumped i just want it to run.

 

[mulldawg]

Don't make it so difficult. The coil is bad, so replace it

+1 1 and 4 are linked on the coil pack.

 

[BlackKnight2013]

have you checked to see if the wires for the coil pack are melted together? there's a small known problem with the wires melting together now an then. you could be getting constant power on the black wire with blue strip if its melted to the black with red strip wire. i have seen the coil wires on 420a's in dsm's and neons melt together and cause this issue. the wires typically melt somewhere between the coil pack and just after the edge of the valve cover.

 

[Moorejoey]

Yes no melted wires the black with blue stripe has constint power in stead of pulsing like it should unlike the brown wire its pulsing like it suppose to I thought it was the coil to but put a known good 1 and still no pulse on black and blue wirl

 

[1G Eclipse94928]

Yes no melted wires the black with blue stripe has constint power in stead of pulsing like it should unlike the brown wire its pulsing like it suppose to I thought it was the coil to but put a known good 1 and still no pulse on black and blue wirl

Do the 420A's have a power transistor? I know the dsm's do and can cause similar issues. If you google you will get a full list of everything it can be, then just test each item and you will know, if your not willing to do that take it to a shop and they'll figure it out quickly, they wouldn't charge you for more then an Hour to figure it out.

 

[BlackKnight2013]

the 420a have a capacitor for the coil to suppress radio frequency noises. since you have a known good coil and know part of the problem. the next best thing to do is to take a multi-meter and check wire continuity for the coil wires and see if the wires are shorted somewhere between the ecu and the coil with the computer unplugged and the coil unplugged.

 

[Moorejoey]

Ok I will have to go get me another multimeter I shut mine up in the hood of the car cause of geting mad at it and the capacidor wire is broke off of it so would that be the problem all along I never noticed it till tonight while working on it? Thanks again for all the advice guys

 

[BlackKnight2013]

Ok I will have to go get me another multimeter I shut mine up in the hood of the car cause of geting mad at it and the capacidor wire is broke off of it so would that be the problem all along I never noticed it till tonight while working on it? Thanks again for all the advice guys

the capaciter wouldn't cause the problem your having. all the capaciter does is reduce Radio Frequencies and stabilizes the voltage.

have you tried an known good computer yet?? i know you have mentioned trying your buddies computer earlier. just breaking things down a bit, you have a known good coil, good cam and crank sensor. the only things that are left to check is your timing belt to see if it hasn't slipped, try a known good ecu and a possible bad wiring harness.

do you have any check engine light codes??

 

[Moorejoey]

Ima get a new computer and see what happens and ill check the timeing I didnt think it slipping would effect the firing bt will check and no no cel iv even let it run till normal temp trying to get it to come on and it wont only when I first start it for the self check it comes on.

 

[poonman]

First thing you need to do is check the three wires going into the coil pack and see what if any voltage you are getting.

Coil one fires 1 and 4 and 2 fires 2 and 3. Center wires should be 12 volts

Coil one is on the right pin and 2 is on the left pin. See if your getting a negative signal to your Pin 3 IE on the right.

And check the Continuity. Pin 1 brown wire goes to pin 3 on the ECU. Pin 3 Black/Lavender goes to pin 11 on the ecu. Make sure you have continuity before you go buying anything.

 

[Moorejoey]

Ok went and got me a new multimeter and traced the wires all the way to the compter mounted on left sidand all3 3 wires run into it and I tested them and still black and blue has continuous power other two are good and brown is posing like it should but black and blue is no. my question is is the computer under the hood that the PCM or the ECU my chilton's book says it's the PCM but then it says the ECU and then it says the ECU is under the bash so which
is which and I found the 1 under the dash

 

[BlackKnight2013]

Ok went and got me a new multimeter and traced the wires all the way to the compter mounted on left sidand all3 3 wires run into it and I tested them and still black and blue has continuous power other two are good and brown is posing like it should but black and blue is no. my question is is the computer under the hood that the PCM or the ECU my chilton's book says it's the PCM but then it says the ECU and then it says the ECU is under the bash so which
is which and I found the 1 under the dash

the 420a computer is under the hood on the left side next to the fuse/relay box. the location under the dash is where the 4g63 engine computer goes which won't be there sine you have a 420a engine.

for a continuity check, you unplug the computer and coil pack connecter(s), fine the wire in the computer connector and back probe it with a t-pin (a sewing needle will do the trick too) and do the same for the same wire color on the coil connector. if the meter beeps then you have a good wire or also known as continuity. to check for shorted wires you take one lead to one of the coil wires at the coil and then you probe the other two wires one at a time. if the meeter beeps or shows less than 5 ohms of resistance you have a shorted out wire somewhere in the wiring lume.

 

[Moorejoey]

Ok so whats bthe module I found under the consol up inder the radio? Also tested the black and blue wire from the computer and getting no 0.04 so I think its the computer?

 

[BlackKnight2013]

Ok so whats bthe module I found under the consol up inder the radio? Also tested the black and blue wire from the computer and getting no 0.04 so I think its the computer?

so the wire is fine, i would say the computer is shorted out internally. a new computer is needed.

is your car an automatic or manual transmission?? the only computer under the radio is the automatic transaxle control module

 

[Moorejoey]

Ok ganna order a new computer and also your correct its auto unfortunaly so thats what it is thanks for all the info blackknight been alot of help. Ill update when I get the new comuter and let you know what happens thanks again!

 

[BlackKnight2013]

Ok ganna order a new computer and also your correct its auto unfortunaly so thats what it is thanks for all the info blackknight been alot of help. Ill update when I get the new comuter and let you know what happens thanks again!

your welcome for the information and glad to be of some help to you.

wish you luck with the computer.

 

[Moorejoey]

1 more? Do I have to get the comuter flached in the eclipse like a neon has to be?

 

[BlackKnight2013]

1 more? Do I have to get the comuter flached in the eclipse like a neon has to be?

its a good idea to get a computer that has been pre flashed for your year make and model also they will ask for your vin number.