running on two cylinders

[tode5tool]

ok, im loosing my mind about this thing, im running on two cylinders.. the bad ones are the 2 and 3. Ive replaced the right side coil pack, this was the one not getting any spark to the plugs, its the one farthest from the PTU and Ive replaced the PTU. ive swapped out the plug wires to the good coil and it still didn't fire on the 2 and 3. I got a brand new set of 750cc FIC injectors, and a brand new 99 eproms from keydriver. this all started happening about 2 weeks ago going to work at 6am. then i limped home and me and a friend was looking at it later that day. we looked for about 30 mins turning it off and on then on one start it decided to work. it worked for only about 6 hrs that day. it hasn't ran on 2 and 3 since. could the problem be the fact that i didn't change out the coil closest to the PTU and just the one to its right? could the cam position sensor do this? also, i took apart the PTU connector and replaced a few connectors that were corroded, i put them back in one by one in the right places. I KNOW.. its not recommended, but its works. so its not the plug.

 

[gofer]

Sounds like you did everything backwards from what you should have. In any case a DSM begins to idle on only cylinders #2 & #3 the first thing I look at is the CAS. If its intermittent it could be the connector on the back of the CAS, mine cracked causing it to drop 2/3 intermittently so I had to replace it.

You've already swapped in pretty much everything else, ensure your noise capacitor is bolted securely to a ground and then replace the CAS.

 

[crazyquik22023]

ya i'd check the CAS, if that is not the problem then i would try checking the wires to the ecu, and the actual ecu itself(even though that is probably not the problem)

 

[tode5tool]

OK, Ive got a question about the CAS. I started the car.. gaaa. and it hardly made a difference when i unplugged the CAS. I did this a few times and even though it was idling around 300 rpms it maybe dropped like 50 rpms then went beck to 300. Wouldn't unplugging the CAS kill the car?. and another thing, is there a better way to test it? also i did just check the plugs on the ecu and they were tight.. to bad. i really want this to be something that simple.

and what the heck is the noise capacitor?? . and where is it?

 

[Chrispy0530]

I had this very same exact problem you did, and swapped everything possible.

Here are 2 threads for some references.

My thread,
http://www.dsmtuners.com/forums/newbie-forum/375364-electrical-2g-problem.html

Another similar thread,
http://www.dsmtuners.com/forums/newbie-forum/374789-cylinders-2-3-no-spark-coil-pack-plugs-good.html


What ended up being my problem was the actual Transistor Power Unit ( I'm guessing this is what noise capacitor is? I have no idea ) PLUG. Not the unit itself, but the plug that actually goes to it from the harness. I cleaned it up a bit due to some corrosion that was inside and it fired right up on all 4.

Bought another TPU plug off a junk yard and plan on swapping the plugs for piece of mind.

 

[tode5tool]

well, i did that today. i pulled the connector apart.. well more like smashed it open. but all the same.. and i replaced a few corroded plugs. there were 2 that were a little green, i dont think its the plug. we've been over this. i think it might be the CAS.

so the noise capacitor is the power transistor? but dont it already have a ground wire going to it? it didn't make a difference bolted up or unbolted. but ill bolt it up and see if that fixes it. i didnt bother bolting it back up after i replaced the wires just for a test, then i had to pack up for the field.

 

[bsbllfit7]

just had this problem and swapped to a 1g cas with a pre made wiring harness for the swap and all is well

 

[tode5tool]

man it seems that one problem can be 100 different things. i had a idle surge problem that wasn't the IAC, FAIV, ecu, plugs, injectors or anything else i could replace.. it was the modulator on the intake manifold, the vacuum hose going to it to be exact. Frekin dsm's man. love and hate um.

 

[tode5tool]

so, the cas was not the issue. im replacing my other coil to make shure there not the problem. there old and nasty anyways, thay can be replaced with no consequence and i get them for 30 bux so whatever. i did something intresting, i switched the wireing on the back on the coils around and changed the fire order to the corresponding coils, and it fired right up and ran on all 4, but today when i tried it.. it ran on 2, i did nothing, all i did was not touch it fro 2 days... i dont get it.

 

[bsbllfit7]

correct me if im wrong but then wouldnt that be the coils being the culprit if it worked when you changed it but now nothing, someone else chime in

 

[tode5tool]

this car is driving me nuts. when i changed out the coils and reversed them, it was just a fluke it ran on all 4 that time. ive checked and rechecked the ptu connector and ive changed out the cas, ptu, coils, plugs, checked the brand new ecu,and redone the ptu connector. What is makeing this car run on 1 and 4. i cant figure this out. and frankly im about to push it into the street and light it on fire. hwat else can make the car run on 2 if not any of these?

is it possible that the crank angle sensor is doing this.. ive done checked everything else.

 

[bsbllfit7]

you should just do a 1g cas swap thats what i did and got rid of this problem

 

[tode5tool]

you should just do a 1g cas swap thats what i did and got rid of this problem

by using a 1g cas it will replace the cps right.. the 1g cas does both jobs?

 

[banishedmunk]

try putting the stock injectors and stock ecu back in. if that fixes the problem get in contact with key diver and they should fix the ecu

 

[tode5tool]

i think i might have found the problem here. i was looking at the CPS wire and thought.. if the car were on and i jiggled it around i might get a response. well it didn't do anything, but it was real loose and i could feel it hit the timing belt. i have a suspicion that the wire could have been rubbed down to the core and is cut or shorting on each other. im going to take a look at it as soon as possible, but i got to go to frekin gunnery on Friday... again.. i have to grade. yay no sleep for me for 50 hrs again.

 

[ziggo0]

2 cylinders also won't fire if your coil pack is taking a dump on you...you may notice other electrical problems such as your gauges (rpm) freaking out as well. Try swapping it with a known working one.

 

[tode5tool]

2 cylinders also won't fire if your coil pack is taking a dump on you...you may notice other electrical problems such as your gauges (rpm) freaking out as well. Try swapping it with a known working one.

ive done that, but i do have another coil coming soon. ill put that in but im not real confident thats the problem.. ill put it in with high hopes to only throw my keys across the street again.

 

[bsbllfit7]

if it is the cps go with the 1g cas and a harness from ebay, saves so much time and money from having to take everything off and its only one part instead of two!

 

[Chrispy0530]

^+1 on this.


Trust me, I know your pain. I went quite a while with my 2 cylinder miss-fire problem. Electrical problems are horrible on DSM's.

 

[Timechg]

I had a similar problem that you had. I tried ignition coils, wires, spark plugs and the PTU. It ended up being a bad O2 sensor. I unplugged the sensor and it ran on all cylinders and replaced the sensor (don't do this for too long otherwise it will dump fuel in the cylinders). It wouldn't hurt to try.

Tim

 

[evileclipse909]

If some of the pins on the ptu harness connecter are green that means they are corroded and not making contact with the ptu. Just get a new pigtail from a junkyard and solder it on. better to replace that then to keep going back and forth. especially since yours sounds quite screwd since you "smashed" it off,.

 

[tode5tool]

If some of the pins on the ptu harness connecter are green that means they are corroded and not making contact with the ptu. Just get a new pigtail from a junkyard and solder it on. better to replace that then to keep going back and forth. especially since yours sounds quite screwd since you "smashed" it off,.

i took care of that. i just replaced the individual connectors in the plug.. just minus the plug now. im 99% sure my problem is my crank position sensor. i dont really want to make a 1g cas fit to replace both 2g cas and crank position sensor.

ive got a question about the CPS. when searching for the sensor, i see two different things.. a sensor that looks a lot like a cas then a pig tail, that looks like it should hook up to a sensor. what the hell do i buy. im sure when i take the timing belt cover off ill be able to make a better call on it but i was just curios.

I had a similar problem that you had. I tried ignition coils, wires, spark plugs and the PTU. It ended up being a bad O2 sensor. I unplugged the sensor and it ran on all cylinders and replaced the sensor (don't do this for too long otherwise it will dump fuel in the cylinders). It wouldn't hurt to try.

Tim

wow... really. sry i dint see your replay till now.. thats amazing that a o2 senor would do that.. was it before that cat or after


so.. if i do go with the harnsess.. witch ill probibly have to do.. i dont want to take the timing belt cover off. would i need a black top or green top cas?

i dont mean to bump, but i just ran a few test. did the hole unplugging both o2 sensors and nothing, then i swapped in my old ecu and still nothing, so ive got a delema here. we now know its not the coils, plugs, wires, cas ecu or o2 sensors. not to sure on the ptu still but ima run a test on it to make sure. its new but we all know not all new parts work. then my cps, for it to be partially working it has to be physical damage to the sensor its self, becuse if its broke my car shouldn't start at all. like crank walk or balance belt broke it.. i really hope its not crank walk.. cuse that would mean some serous walkin to brake that sensor.

 

[bsbllfit7]

not true, my cps began going out after i got a lightweight flywheel, there are many threads on this on here about people that get lwfw's and cant cruise between 70 and 80 or else the car will go into like a two cylinder mode, restart the car and it works, the reason this is happening is that the sensor has not failed completely but is on its way out, the light weight flywheel picks up the increased harmonics from the lwfw and sets it off. The sensor can be going bad all the time without it being completely off. A 1g cas is a simple way to replace the cps and cas in one false swoop. No re doing timing or taking a camshaft off to replace a sensor, simply get the sensor, either green or black top (i heard black tops dont give random multiple cylinder misfire codes) take the valve cover off, take the plug out and put it in. Its really simple and there are pre made harnesses on ebay that a guy on here sells for about 40 dollars shipped! its about 100 dollars total for the job with a used sensor. About an hours time total to install and thats with setting base timing! If you need more help i can shoot you any info you need as i just went through this job 2 weeks ago.

 

[tode5tool]

that's interesting, I do have a LWFW in my car. ive had it in for about 2k. i think im going to go with a 1g cas. im so tired of this. i need this car to get to work.

 

[bsbllfit7]

smart choice, the 3 things i can come down to for stuff like that is cps cas and coil packs. Might as well do the upgrade to a 1g cas that fixes two of those problems in one. and you already put in the new coils