420a intermittent loss of ignition/injectors (12 month problem) PLEASE HELP

[starquest87tsi]

hello, I have yet to find any articles of a 420a dsm having this issue. this is an intermittent problem, and sometimes I can drive the car just fine, other times it is such a pain to go anywhere. it will die and sometimes jump itself back into life, though sometimes ill sit there for over an hour until it'll start back up. I am having in intermittent loss of power to my ignition coil or my fuel injector pulses, I've noticed that when driving, the CEL and Battery light on the dash will turn off, I have always bad a CEL and its not a big deal, and I am running a deep cycle battery optima. I've noticed that all the lights will come on with the run position, and WHILE CRANKING it will quickly flash the CEL, battery light, and cruise control light. when the intermittent no start occurs, none of those lights come on while CRANKING. my srs and the seatbelt light do not lose power, so i believe that whatever is causing this problem is linked to whatever flashed the CEL, battery, and cruise control light. I have checked everything in the fuel and ignition system and replaced over 1000$ worth of parts on my 96 talon esi. I bought a brand new PCM and it didn't help at all, I have had several electrical shops look at it and they can't figure it out. I have torn this car apart 50+ times looking for the issue, and it really sucks because i put so much love and money into this car, and it is also my daily. i feel like my talon hates me. please help, anything is appreciated.
-jake z

 

[BLACK'98DSM]

Have you checked any of the relays? How about the fuses? Are you sure you have good connections?

My best bet would be the relays but take all options into consideration, as sometimes the problem is far astray.

 

[starquest87tsi]

yeah all of the fuses are good, and I've redone the whole ignition switch wiring. I've looked at the relays but I haven't changed them. the only things I haven't changes relating sensors would be the CMP and the o2 sensors. still dying on me every day, I can somewhat drive the car but it sucks when it dies on me in traffic. :/

 

[starquest87tsi]

what could cause the CEL and Battery light to turn off and lose ignition/injection randomly? and what makes those 2 lights flash while cranking?

 

[Norven Echevarria]

hello, I have yet to find any articles of a 420a dsm having this issue. this is an intermittent problem, and sometimes I can drive the car just fine, other times it is such a pain to go anywhere. it will die and sometimes jump itself back into life, though sometimes ill sit there for over an hour until it'll start back up. I am having in intermittent loss of power to my ignition coil or my fuel injector pulses, I've noticed that when driving, the CEL and Battery light on the dash will turn off, I have always bad a CEL and its not a big deal, and I am running a deep cycle battery optima. I've noticed that all the lights will come on with the run position, and WHILE CRANKING it will quickly flash the CEL, battery light, and cruise control light. when the intermittent no start occurs, none of those lights come on while CRANKING. my srs and the seatbelt light do not lose power, so i believe that whatever is causing this problem is linked to whatever flashed the CEL, battery, and cruise control light. I have checked everything in the fuel and ignition system and replaced over 1000$ worth of parts on my 96 talon esi. I bought a brand new PCM and it didn't help at all, I have had several electrical shops look at it and they can't figure it out. I have torn this car apart 50+ times looking for the issue, and it really sucks because i put so much love and money into this car, and it is also my daily. i feel like my talon hates me. please help, anything is appreciated.
-jake z

May sound wered or crazy but some car wont handle optima batterys do to much power or somthing not sure but try a regular battery to see if it fix the problem

 

[ThunderChild]

I'd put money on the crank position sensor. Common problem if the car is shutting off randomly.

Is it more-so when the car is warm, cold or doesn't relate to run-time/temp? Previous ones I've worked on had old CKP's, and the internal seal would go had or housing would crack and allow oil to enter the sensor and foul it, usually once the car was warm. Could happen 5 min or 2 hours into driving. Replaced sensor, issue gone.

 

[starquest87tsi]

I've replaced the crank sensor but not the cam sensor yet, ill try that next. kind of weird note but it happens less often in the morning I've noticed, although sometimes the car won't start at all and I have to wait it out. funny thing, I'm currently stuck right now waiting on it to start

 

[ThunderChild]

My next question would be: what's the the crank sensor wiring?

Cam sensor is the next thing, could be faulty causing the fuel to cut in it.

 

[starquest87tsi]

I had to do the ckp new pigtail to get it to connect, and it hasn't made a difference with the new one. I've also got like a 5:1 air fuel ratio terrible gas mileage. think I also need to replace my o2 sensors.

 

[starquest87tsi]

cam pos sensor wiring also has a code related to the wiring of it, I need to check into what could be causing that as well.

 

[starquest87tsi]

Just bought the cmp sensor, hopefully should help. i am also going to clean the plugs and get new o2 sensors, upstream and downstream from cat. thanks for all your input, ill keep everyone updated.

 

[starquest87tsi]

replaced cam pos sensor and the pigtail that goes to it, ive driven the car for 3 days and it hasn't died once on me. after 1500$ in parts and a new PCM, it was my cam sensor and wiring to it. Thank you all so much, i'm so thankful that it can daily drive now. ill post if anything changes. still running rich, any info on that? would it only be o2 sonsors?

 

[ThunderChild]

Glad it's staying running! As for running rich, I don't recall, but have you check to make sure an injector isn't stuck open? Might pull them out and run some fuel through a tube to each injector to see if they're leaking at all. Otherwise it's have to be a fault with the pcm or some aftermarket parts.

Are there any other mods done to the car?

 

[starquest87tsi]

okay, I did just put in a brand new remanufatured pcm about a month or so ago, and I will do that injector test and hopefully they are good. I have spare injectors also. thanks for all your input, ThunderChild!! i will keep you posted! will o2 sensors help at all?

 

[silvreclips]

The front 02 sensor will effect fueling, the ECU uses this data to adjust the mixture to try and stay at stoichiometric. If the sensor is giving incorrect readings then yes it can cause the motor to run bad or get poor fuel mileage. The rear 02 only checks to see if the Cat is working. It has no impact on performance

 

[starquest87tsi]

thank you so much!! that helps alot

 

[BLACK'98DSM]

The rear 02 only checks to see if the Cat is working. It has no impact on performance

But it will trigger the check engine light.

 

[starquest87tsi]

my CEL is always on . it says lean, but I haven't cleared them yet. I did an exhaust gas analyser and it read a 4:1 air fuel. I go through a quarter tank a day haha

 

[starquest87tsi]

It probably shouldn't even scientifically run.