1G Car died

[blaze12]

So yesterday i finally got done with a new wheel bearing and control arm and tie rod replacement on my laser and i started it up and took it for a spin to see if my wheel bearing noise went away and it did i was so happy because it was the last thing keeping me from getting my car inspected. So anyway i took it home parked it in my garage and then asked my sister if she wanted to take a ride so i could show her what ive done with car and then the car wouldn't start . Im so confused for all the months ive had it , it never hasn't started up . All i did before i started was put a little oil in it . Because it was low . So today i tried starting it again and it did start but than died super fast like if my maf was bad. When i crank the car i smell fuel so i thought there was no spark but then i bought new plugs and wires and still nothing . My question is how can the run perfectly fine one moment and then try to start it literary 4 minutes later and nothing?

 

[blaze12]

yes but a boost leak would have nothing to do with fuel and spark right?

Also the car he was running was a s2k.

Ok just tested the sensor going to the cas sensor and its not getting voltage so would this be an ECU issue?

 

[blaze12]

OK my cas sensor isn't getting any voltage what to check next for the reason why its not. Is this an a ECU problem?

 

[Tyeler18]

Why don't you stick with one thread and just update that one. No need for 10 threads.

What do you mean it's not getting voltage. Please explain.

 

[blaze12]

Sorry no one was responding , i checked voltage on the connector going to the CAS sensor on terminal 3 and nothing no voltage .

 

[turboJAKE]

trace it back to the ecu see if you have voltage there if yes find open in wire
if no bad ecu

 

[blaze12]

how do i trace back rip open the wiring harness

 

[luv2rallye]

how do i trace back rip open the wiring harness

First unplug CAS, then with key on, check if have +12V on the CAS red harness wire. If no, check for +12V on red wire at MPI relay.

If +12v is on CAS red wire, then turn key off and disconnect battery negative. Next unplug ECU (and keep CAS unplugged). Now test for continuity between CAS white and ECU pin 22 harness connector. Then CAS black on pin 4 (next to the white - not pin 1 black which should go to ground - which you should also check) for continuity to ECU pin 21.

ECU pinout:
1G ECU Pinouts

 

[JusMX141]

All three threads you've started on the same topic in the past three days have now been merged. Carry on.

 

[STLskater92]

All three threads you've started on the same topic in the past three days have now been merged. Carry on.

Thank you Jusmx141!!! I've been trying to follow this thread at 3 different places

Now to the OP, try what you know or think is bad, you brought up the CAS and how you know it was bad, so change it. If that isn't your problem, then start back tracking from there to your ECU. Check every connection point and wire.

Next i'd move on to your charging system starting with your altinator and recharg your battery. Have you reciently gotten a new altinator? I got my car for $700 because the kid before me had the altinator go bad and the new one he bought was bad to sart with and he gave up looking (his lose, my gain )

From there look for an accidental ground along any power wires starting with battery termanals and working to the alt. and every point a power line goes to.

Do you have any after market electronics in the car? Subs? Head unit? Amp? All of these could have a faulty power line and can drain your battery and cause it not to start.

As for the boost leak theory, have you ran a BLT? Why ask if a boost leak could cause it when you should check your system regulary to maintain a leak-free system

You asked for a list of other possibilities, and there it was. I'd start at thetop of the listand work your way down as the list gets less and less likely to be your problem. Get back with me with some answers and I'll try to help you narrow it down even more. Good luck

 

[blaze12]

thankyou guys fo all the help

 

[blaze12]

OK pulled my ecu and mpi off , how to test them ?

 

[luv2rallye]

MPI: http://www.dsmtuners.com/forums/newbie-forum/263224-mfi-mpi-relay.html#post151211808

ECU: Can't really test them. All you can do is swap with another one or if can't do that, open it up and look for leaking capacitors (usually smell like rotten eggs) and broken/burnt foil traces. http://www.dsmtuners.com/forums/articles-tuning-ecu/116585-troubleshooting-fried-ecu-components.html

 

[steve]

Reposting from the email reply to the OP, since it covers part of what basic tests you can run on the ECU.

Starting and running for 2 seconds would typically be related to the fuel pump not being kept turned on. On a 1G the pump starts from the starter signal and as soon as the ECU sees that the engine is turning it activates a second input to keep the fuel pump running after you release the starter. The most likely cause is the ECU can't activate it's input but a bad MPI relay can also do it.

When the car won't start at all you need to watch the CEL. It should turn on for five seconds and turn off each time you turn the ignition on. The turbo cars will in addition more the factory boost gauge to 0 when the ECU is on and them move to -7 during cranking and once the engine starts. If it doesn't start it will return to 0. These are the quick test that the ECU powered up and is running. If the ECU doesn't power up nothing else interesting is going to happen.

All original ECUs have a problem with the capacitors leaking and damaging the ECU, most repaired ECUs were done as cheaply as possible so having a rebuilt ECU is no indicator that it's good. One common leakage sign is that the fuel pump won't stay running. Another is the car randomly dieing with the CEL turning on briefly.

The Oil Pressure Sender has no interaction with the car starting or running. If it's damaged you might not see any pressure on the gauge.

The Engine Coolant Sensor can cause a car not to start or be hard to start because when it's disconnected or dead it will make the ECU think it's really cold and the ECU dump fuel into the engine in an attempt to get some to vaporize and ignite. If it's not really -39F outside this will flood the engine.

If you not seeing spark, there can be many causes but combined with your other symptoms a bad ECU looks more and more likely.

 

[blaze12]

I just dont get how my MPI could be bad if the car starts and then dies , also since i put my mfi relay back in , it has started making this clicking noise. Once when i crank and once when i stop cranking any ideas?

Also someone told me to check the fuel filter but how could it be clogged if gets fuel to start and dies exactly two seconds later?

 

[steve]

I just dont get how my MPI could be bad if the car starts and then dies , also since i put my mfi relay back in , it has started making this clicking noise. Once when i crank and once when i stop cranking any ideas?

The MPI relay controls two things, the power to the ECU and sensors, and the power to the fuel pump. Every time either is activated the relay will click.

The ECU and sensor power is activated by the ECU when you turn on the ignition switch and deactivated about 10 seconds after you turn the ignition off (from Run to ACC). As I mentioned before when you turn the ignition on, the MPI relay will be activated, the ECU should turn on the CEL for 5 seconds and then turn the CEL off unless you have a stored fault in which case it will stay on. When you turn the ignition off you should hear the relay click about 10 seconds later.

The fuel pump power is activated by two inputs. The first is the starter circuit. When you are cranking the engine via the starter the MPI relay turns on the fuel pump and as soon as you stop cranking that input is deactivated and if the second input isn't activated the relay will click off. The second input is from the ECU. When it sees CAS pulses it activates the second input for as long as it continues to see pulses. Once the pulses stop the ECU will delay a few seconds and turn the second input off. Some CAS's pulse on power up which makes the ECU think the engine is turning and cause it to turn the pump on shortly. This confuses some people into thinking that the pump primes when you turn the ignition on but that's by accident and not by design. Not all CAS's glitch like this at power up. Note then the ECU doesn't have to work for the first input to the fuel pump to function, it's strictly driven by the starter circuit and you can crank the car until the battery dies without an ECU even in the car.

The engine seems to be able to run for a few seconds on the fuel left in the system from cranking. That's why I usually suspect the ECU when people say they started the car and it dies after a second or two.

Please let us know if the CEL and boost gauge are behaving as described. This is a quick check and will save a lot of guessing.

 

[blaze12]

Ok today i picked up an eprom ecu and MFI relay and injector tranzistor for 150 bucks and put on my car and it started and stayed running but only if i would give it gas and it would jump around like crazy with rpms , like i was giving a steady amount of gas trying to hold it aroung 2000 rpms but it would jump back and forth from 2000 to 2300 back forth it sounded like hitting the rev limiter . I havnt started the car since cause im scared that i might ruin this ecu because someone told a bad isc motor can ruin an ecu and i just put on a different throttle body on my car with a used isc motor on it . When you put on a new ecu on your car should it just work perfectly or does it have to learn and make adjustments , did i give it long enough to learn .

 

[steve]

Which ECU exactly did you put into you car?
In general you should only change one thing at a time. Otherwise you have no idea which what.

 

[blaze12]

Its a eprom ecu for a turbo manual car and i did put one at a time.

1 MFI didn't help
2 Transistor didn't help
3 ecu worked but not much

 

[steve]

Its a eprom ecu for a turbo manual car and i did put one at a time.

1 MFI didn't help
2 Transistor didn't help
3 ecu worked but not much

Did you put the old parts back in when the replacement didn't make a difference?

Telling me that it's a "eprom ecu for a turbo manual car" isn't exact enough. I can't give you advice without knowing:

What are the numbers on the case?
What is the number on the white edge connector? (assuming you can open the case)
Where did it come from?

If you had a bad ISC with a shorted coil (there are other types of bad ISC) it damaged the ECU within microseconds of turning on the ignition.

It clear that the ECU was the cause of it dieing after a few seconds. Now the question is if there is still an ECU problem or if you created additional problems trying to solve this.

It's not clear how much of the following was done before or after you started having problems or is still left to be done.

Changed the plugs and wires. Are you sure they are gapped correctly and that the wires are on the correct coil?

Changed the throttle body. New gaskets? Reinstalled the throttle body ground strap? Correctly adjusted the BISS? Checked for boost leaks?

Fixed the ECT sensor (engine coolant temp)?

Moved the CAS while testing?

You are the eyes and ears, the more specific you can be the more likely you'll get useful feedback. Otherwise you're likely to get guesses.

 

[blaze12]

well now the car wont even turn over i have no power but i have 14 volts at the batt so confused .

I tried jumping the car and nothing then let it sit for 10 minutes came out and the car lights where working but as soon as i cranked it would die it wouldn't even turn over i know its something to do with the power . Does anybody live in Missouri or better yet st. Charles that could come over give me a hand . Every time i fix something on this car , something else goes wrong . I heard dsms were unreliable but damm.

 

[steve]

Get the factory service manual and start diagnosing.

Remember what I said about guessing, so far your just describing symptoms that could have many causes. It's good that you checked the battery voltage but what happens when you turn on the ignition switch before even trying to crank? Do any lights turn on, can you turn on the radio?
What happens when you try to crank? Any clicking or any sounds from the starter? Do the lights go off?

I see you added some information. Knowing that the light die when cranking is good information. Do they stay off? What's the voltage during cranking and after?

 

[blaze12]

The car doesn't even really crank as soon as i turn it to the on position the car dies and lights go off.

 

[steve]

Charge the battery and check the battery terminal and grounds.

 

[blaze12]

I checked the battery voltage before i turn the key to the on position then i check after and it is zero but i will 1 minute or so and check voltage and the batt is back to 12 volts so confused is it possible that the power is jumping somewhere and not going to the ignition .

Does the ecu control weather the ignition gets power or does the batt just send it straight to the started?

Could this be because of the ecu might be ruined ?

 

[STLskater92]

Whatever you did last caused it to stop cranking over. Back track through everything putting the old parts on untill you can start the car again.