car runs but only on numbers cylinder

[92TlnTsi]

Need a little help with running issue . It all started with car running fine started missing now only runs on the number 4 cylinder with no codes although it will run on starting fluid. I have replaced coils, plugs, wires, transistor, cas, ecm with no change. I checked injector pulses 2&3 have no pluses 4 is good 1 is very weak. Any help/advice would be greatly appreciated.

 

[92AWDHX40]

Could be a wiring issue, or injector, several things.

 

[92TlnTsi]

Since my last post I have ohm ed the injector wires from ecm to injectors all .2 ohms or less anyone got any thoughts of what could be the issue here . I really dont know of any other things to check.

 

[gar187er]

when you replaced the coilpack, did you replace with a new one?

you also said you have no spark on 2 and 3, so then why did you change the plugs?

 

[jared_gibbs]

You only need 3 things to make your motor run: air, fuel spark.

If it runs with starting fluid my attention is drawn to a fuel issue. Starting fluid won't ignite without spark.

I think your problem is with the injectors (point 5 below) however let's rule a few things out first...

1. Why did you replace the ecm (ecu? same thing?). Verify that it is EXACTLY the correct one or you may have issues. It should be same year, exact same trim, hell even the CA models had different ecu's. If your old one didn't have leaking capacitors and you're sure it was what came with the car from the factory I suggest you throw it back in there.

2. Plugs correctly gapped?

3. Coil pack connectors plugged in? There's an upper one and one below that, make sure they're both in.

4. Slowly pull out the spark plug wires from the plugs end just enough to hear the "popping" sound. If you hear it, you've got spark. Don't pull them all the way out or you'll zap yourself or start a fire!

5. Fuel. Let's start with the injectors. No CEL's means wire harness is likely fine. Use a stethoscope and listen to hear the injectors firing. I think you will because if they weren't firing at all it would be due to an electrical issue and it would trigger a CEL. I think they're clogged. Pull them and clean with carb cleaner. A double A battery provides the necessary 1.5 volts to open the injector so you can give them a good douching. Your injectors may have been plugged due to a rusted fuel tank. If cleaning the injectors cures the issue I recommend you pull the tank and a have a radiator shop reline it. Probably need a new fuel pump at this point if you've still got the factory one in there.

That 92 is an excellent year! Please don't get frustrated and F*ck it up!

 

[russell3123]

Might have the wrong year ecu? Are you sure the cas or ecu you swapped in are good? If the ecu you swapped in was a 90 you have to switch the firing order. Or you have to switch pin 6 and 14on the ecu i believe.

 

[gieri002]

You only need 3 things to make your motor run: air, fuel spark.

If it runs with starting fluid my attention is drawn to a fuel issue. Starting fluid won't ignite without spark.

I think your problem is with the injectors (point 5 below) however let's rule a few things out first...

1. Why did you replace the ecm (ecu? same thing?). Verify that it is EXACTLY the correct one or you may have issues. It should be same year, exact same trim, hell even the CA models had different ecu's. If your old one didn't have leaking capacitors and you're sure it was what came with the car from the factory I suggest you throw it back in there.

2. Plugs correctly gapped?

3. Coil pack connectors plugged in? There's an upper one and one below that, make sure they're both in.

4. Slowly pull out the spark plug wires from the plugs end just enough to hear the "popping" sound. If you hear it, you've got spark. Don't pull them all the way out or you'll zap yourself or start a fire!

5. Fuel. Let's start with the injectors. No CEL's means wire harness is likely fine. Use a stethoscope and listen to hear the injectors firing. I think you will because if they weren't firing at all it would be due to an electrical issue and it would trigger a CEL. I think they're clogged. Pull them and clean with carb cleaner. A double A battery provides the necessary 1.5 volts to open the injector so you can give them a good douching. Your injectors may have been plugged due to a rusted fuel tank. If cleaning the injectors cures the issue I recommend you pull the tank and a have a radiator shop reline it. Probably need a new fuel pump at this point if you've still got the factory one in there.

That 92 is an excellent year! Please don't get frustrated and F*ck it up!

You need 4 things for an engine to run. You forgot compression...

 

[Hillala]

I agree with gibbs, It sounds like a crapped up injector issue. Back wash them so they have a clean flow and change out your fuel filter while you're at it.

 

[boost97gst]

Hold on hold on. He claims he checked the injector pulses and got nothing on 2 of them. Cleaning injectors wont fix that. How did you check the pulse? Did you hook up an O scope and probe both sides while cranking or running? Did you just use noid light? I can tell you the noid lights oreilly loans out are no good for my dsm. None of them lit up at all and i DID verify good pulse with a very nice o scope. I think the bulb needed to be a diode to react quicker. Just a guess.
Anyway, elaborate on how you came to the conclusion there are no pulses on 2 injectors please

Edit: FYI, i cleaned an injector with carb cleaner, a small hose, 2 alligator clips and a 9v battery on my Lincoln about 6 months ago. Runs like a champ now. Just dont hold the clips on too long or you run the risk of opening the coil in the inj. Just tap tap taparoooo

 

[Hillala]

My bad, I was reading that wrong. Yeah, if you're not getting a pulse for two of your injector plugs, cleaning it wont really help but then again what would explain the strong fuel smell in the oil if they aren't firing at all.

 

[boost97gst]

Yea, he may not have REALLY checked the pulse widths. Thats my suspicion. Tell ya a quick story, a horror story: I noticed that one day while troubleshooting a slight misfire and going through the usual suspects, injectors, wires, plugs all that jazz I came to one terrible conclusion and confirmed it. Cyl 2 wouldnt change the idle when i pulled its inj or plug wire, well come to find out i have 90!!!!psi compression in that cyl and no it wasnt as easy as a bad valve. Its the rings. No fuel in oil, no smoke at idle, even under boost. But leakdown confirmed rings. sucks

I recommend doing comp tests at times. I could have seen this coming probably. Not much i couldve done but atleast i would have seen it. In the OPs case its not the problem, or i dont think so from what he has said. But crazy crazy expensive shit can and does happen no matter how conservative your tune it all boils down to how well your machinist did his job. Im blabbering and whining about my own situation.

OP fill us in, more details brother!

Edit: your 1g, pop your cas off and spin it while the ign is on. Should hear the injectors clicking. Thats a good way to check for pulses. Just a thought...

 

[92TlnTsi]

I have checked the compression 150 to 170 across all cylinders, as for checking inj impulses I used noid lights from autozone with the light bright on 4, dim on 1 and no light on 2 & 3. The ECM and CAS are remanufactured items from oriellys auto but the car will run with either ECM but just on cylinder 4. I have the new CAS in it but can plug in the old one and turn it and hear the idle control working ( at least thats what I think is working). I read a post and it says that if the ECM is seeing lower spark it can shut off signal to injectors is this true I have never heard this. I think I have changed every part thats could cause an problem but have no luck so far.

 

[boost97gst]

Ok so you have checked continuity between injector(s) and ecu and continuity from the other inj wire to the resistor pack? And you have measured the resistor pack? Should be around 6ohms for each injector. Search "test resistor pack 1g dsm" or look in the manual.
Got a strong 12v constant on the injectors? See, you may know this, but there is 12v on both injector wires. When it pulses, the wire that goes to the ecu will pull that to ground giving you a potential difference of....12v across the injector for a short time. You need to verify wiring and 12v and resistor pack.

 

[92TlnTsi]

I have 12 volt on all injectors on both sides of the connectors and also checked the injectors with a AA battery and they click as they should . I have been troubleshooting this thing off and on for a month and was driving the car for the prior 6 months, I appreciate all advise keep ideas comming but I have tested everything I can possibly think of. Thanks

 

[russell3123]

Is the cas 180deg off?

 

[boost97gst]

Ehh even if it was it should still fire the injectors, just not in the right order possibly. Its worth a look for sure.

Damn, i want to say ecu but you tried 2 different ones and STILL no injector pulse on the same injectors right? Dude, you have one hell of a problem on your hands. You sound like you know what youre doing quite well and educated well on dsms. Im not sure if i have any more suggestions.

You said something about spinning the cas and hearing "idle control"? Im not a 1g guy but i think you should be able to hear injectors clicking as you spin the cas. That still would leave ya in the same place if you only hear 2 injectors working.

CAS wiring? hmmmmmm this is a good one.

 

[92TlnTsi]

I have tried the cas both ways it can go with no change, trying a mpi relay tonight just for giggles who nows maybe its that its the only this I havent changed.

 

[962ndgen]

I have tried the cas both ways it can go with no change, trying a mpi relay tonight just for giggles who nows maybe its that its the only this I havent changed.

Well from what I read above sounds like you've tested just about everything I would've tested. I guess I'd either check for good secondary coil voltage or the power and ground on your CAS.. Nothing really left.

 

[92TlnTsi]

Does anyone know if the ecm can cut injector impulses if the fuel pressure drops , it seems to have pulses for about one revolution of engine then drops just thinking outside the box a little

 

[russell3123]

I dont think so . The ecm does not have a way of monitoring fuel pressure.

Does youre chech engine light come on when you turn the ignition on ? It should come on for few seconds then shut off. Can you her the mpi relay click at all?

 

[boost97gst]

Its time to break out the pin outs and start ringing every damn wire in that car. At this point it has got to be a wiring issue somewhere. I have no idea what to check next.

 

[92TlnTsi]

UPDATE!!! Finally figured out what the problem was. I Was feed up with it took it to a mechanic put it on a scope and it had ALL injector pulses and good fire as well, so he pulled the injectors and 3 were stopped up with very fine rust particles looked like dust. Cleaned tank and injectors now it runs. Lesson learned dont trust NOID LIGHTS, I would think if there was pulse on one injector the rest should too. But who knows with electrical systems on older cars, anyways THANKS for everyones input.