That depends. If it failed in such a way that it is allowing exhaust gasses to pass into the intake all the time, then yes... a bad EGR will prevent you from starting or running the engine. So will a rotted out EGR tube because it will allow too much unmetered air into the intake as well.
Is the ECM running? Indications it is running is that right after you turn the key to on but don't crank it the ECM activates the fuel pump relay for two seconds, and that cause the fuel pump to run for two seconds. Second indication is that the check engine light is on, key on engine off. Both should happen.
Now if that is happening next thing to check is to just bump the starter. Do not crank it. Does the fuel pump come on for two seconds and then turn off? It should. That indicates the ECM is getting the ignition signal from the ICM. - NOTE - Cranking the engine will ALSO cause the oil pressure switch to close and THAT will turn on the fuel pump. So don't get confused by cranking the engine. Only bump it.
So now if the above two tests pass but you still are not starting - Then I would look at the injectors being stuck shut. This does happen on engines that have sat for years. The solution if you are in this situation is to pull the upper intake manifold, the fuel rail and then the injectors. Soak the injector tips in fuel injector cleaner overnight. Do NOT jump to this however unless the engine passes the two above tests.
Is the ECM running? Indications it is running is that right after you turn the key to on but don't crank it the ECM activates the fuel pump relay for two seconds, and that cause the fuel pump to run for two seconds. Second indication is that the check engine light is on, key on engine off. Both should happen.
Now if that is happening next thing to check is to just bump the starter. Do not crank it. Does the fuel pump come on for two seconds and then turn off? It should. That indicates the ECM is getting the ignition signal from the ICM. - NOTE - Cranking the engine will ALSO cause the oil pressure switch to close and THAT will turn on the fuel pump. So don't get confused by cranking the engine. Only bump it.
So now if the above two tests pass but you still are not starting - Then I would look at the injectors being stuck shut. This does happen on engines that have sat for years. The solution if you are in this situation is to pull the upper intake manifold, the fuel rail and then the injectors. Soak the injector tips in fuel injector cleaner overnight. Do NOT jump to this however unless the engine passes the two above tests.
Thank You! the car acts like it has no fuel AGAIN!!! I was thinking the Fuel regulator was bad but now I have to look at the injectors as Im sure the ECM is fully working.
Ill have to check everything again in the AM plus re tap an EGR thread. New EGR & OIL switch is on the way. Is the upper intake manifold gasket reusable or do I need to get a new one? I guess Ill need Injector o-rings too??
Have you tried NOID lights on it to see if the injectors are getting a firing pulse? I suspect the pick-up coil in the bottom of your distributor is shot. The ECM needs a signal from it to keep the fuel pump running.
[This message has been edited by carnut122 (edited 09-23-2014).]
Have you tried NOID lights on it to see if the injectors are getting a firing pulse? I suspect the pick-up coil in the bottom of your distributor is shot. The ECM needs a signal from it to keep the fuel pump running.
The ignition system wouldn't work if the pick-up coil was bad.
Originally posted by phonedawgz: The ignition system wouldn't work if the pick-up coil was bad.
The ignition system worked fine on my 94 Transport (3.1L). The ecm looked for a signal from the coil to tell the engine to continue running. I could dump gas into the throttle body and keep it running, but it wouldn't fire the injectors. Once I changed out the coil in the bottom of the distributor all was good again. I assume it's pretty much the same in a Fiero (or maybe not)???
The ignition system worked fine on my 94 Transport (3.1L). The ecm looked for a signal from the coil to tell the engine to continue running. I could dump gas into the throttle body and keep it running, but it wouldn't fire the injectors. Once I changed out the coil in the bottom of the distributor all was good again.
This makes no sense. If the "ignition system worked fine", why would you have "changed out the coil in the bottom of the distributor"?
This makes no sense. If the "ignition system worked fine", why would you have "changed out the coil in the bottom of the distributor"?
It sends a signal to the ecm that the engine is still spinning and thus still needs fuel past the initial 2 second prime when the key is first turned to on. If the engine is not spinning, the fuel needs to be shut off to the motor. Kind of like a cam sensor or crank sensor lets the ecm know the engine is still spinning.
1) I'll be removing the top of the intake in the AM. Do I need to check for voltage or a signal on the injector or can I just see if it clicks?
2) What do i need for the injectors? just 2 o-rings each?
Noid lights are cheap at Harbor Freight and they plug into the harness instead of the injector. Maybe Auto Zone has them as part of their loaner tools? I suppose there are other ways to see if electrical impulses are reaching the injectors such as a voltage meter or muti-meter, but I'm unsure if it will cause damage to the meter.
It sends a signal to the ecm that the engine is still spinning and thus still needs fuel past the initial 2 second prime when the key is first turned to on. If the engine is not spinning, the fuel needs to be shut off to the motor. Kind of like a cam sensor or crank sensor lets the ecm know the engine is still spinning.
The pick up coil does not connect to the ECM. It only connects to the ICM, which you said produced spark since it would run on starting fluid. That indicates the pick up coil was indeed sending a signal. There would be no reason to replace the pick up coil if it was sending the signal to produce spark to the ICM. The ECM uses the ICM's ignition pulses as a basis on firing the injectors.
[This message has been edited by phonedawgz (edited 09-24-2014).]
Here is a little background information (and I stress ‘little’) explained in plain english, to help you diagnose this NO START/NO SPARK Condition of the distributor. In a nutshell, when you crank up the engine (and the system is working properly):
The distributor shaft starts to rotate, inducing the pick up coil to start generating its magnetic signal. This pick up coil signal is sent directly to the ignition control module. The ignition module, upon receiving this pick up coil signal (for all intended purposes it's a Crankshaft Position Sensor signal) converts it to a digital signal that is now sent to the Fuel Injection Computer. This digital signal is called the: Distributor Reference Hi Signal in the majority of the Service Literature. Also, after receiving the pick up coil signal, the ignition control module starts to switch the Primary Current (of the ignition coil) On and Off. As you might already know, it's this ‘Switching Signal’ that makes the ignition coil start sparking away. OK, once the Fuel Injection Computer receives the Reference Hi Signal, it starts activating the fuel injectors and above 400 RPM's, starts to send a 5 V Bypass Signal to the ignition control module. It's with the Bypass Signal that the Computer starts to retard and advance ignition timing with the IC Signal. So, then above 400 RPM's (any RPM above this and the ECM considers the engine as having started) the Fuel Injection Computer starts to control the ignition timing.
The tests that you're gonna' learn in this article only deal with steps 1 thru' 4, among several tests. But whether your car or truck DOES NOT START or STARTS but runs with a MISFIRE, this is the article for you!"
[This message has been edited by carnut122 (edited 09-25-2014).]
The distributor shaft starts to rotate, inducing the pick up coil to start generating its magnetic signal. This pick up coil signal is sent directly to the ignition control module. The ignition module, upon receiving this pick up coil signal (for all intended purposes it's a Crankshaft Position Sensor signal) converts it to a digital signal that is now sent to the Fuel Injection Computer. This digital signal is called the: Distributor Reference Hi Signal in the majority of the Service Literature. Also, after receiving the pick up coil signal, the ignition control module starts to switch the Primary Current (of the ignition coil) On and Off. As you might already know, it's this ‘Switching Signal’ that makes the ignition coil start sparking away.
Are you trying to suggest that it's possible for a pick-up coil to send a good signal to the ICM (creating spark), but at the same time not to the "Fuel Injection Computer"... thus requiring the pick-up coil to be replaced?
I'm certainly no Fiero electronics expert, but I find that difficult to accept.
[This message has been edited by Patrick (edited 09-26-2014).]
I've seen several instances where the engine would run on starting fluid, even with a new ignition module. The fuel pump would cycle properly at ignition on. What was found was that one of the female pins in the 4-pin harness to the ECM had been pushed back into the harness end, not making contact with the corresponding male pin. It was the wire that sends spark signal to the ECM. Pull the connector from the ECM and look to be sure all 4 pins are almost flush with the end of the harness.
I've seen several instances where the engine would run on starting fluid, even with a new ignition module. The fuel pump would cycle properly at ignition on. What was found was that one of the female pins in the 4-pin harness to the ECM had been pushed back into the harness end, not making contact with the corresponding male pin. It was the wire that sends spark signal to the ECM. Pull the connector from the ECM and look to be sure all 4 pins are almost flush with the end of the harness.
thanks! My EGR was wide open so I blocked it off while waiting for a new one. The next no start problem was stuck fuel injectors. So now Im cleaning injectors. this after the car sat for 21yrs with 13k miles on it, 99% original parts. Only the battery & alternator was serviced back then.
Here's hoping that this is an 88 CJB T-top with 5-speed, Lumbar Support and all the goodies and it was sitting inside, wrapped up and protected from the slightest hint of sunlight. I've saved a couple of Fieros, but it's always great to see someone put the effort into bringing one back that's been out of service for such a long period. Pics and description please, please.
[This message has been edited by fierofool (edited 09-26-2014).]
Are you trying to suggest that it's possible for a pick-up coil to send a good signal to the ICM (creating spark), but at the same time not to the "Fuel Injection Computer"... thus requiring the pick-up coil to be replaced?
I'm certainly no Fiero electronics expert, but I find that difficult to accept.
I'm trying to tell you that I rebuilt my throttle body on my Transport before realizing that the pick-up coil needed to be replaced. And, after I replaced the pick-up coil, the van ran just fine. The van had spark, so I quickly and logically deduced it was a fuel related problem. However, initially, I assumed it was a fluid delivery problem and not an electrical issue. It would run as long as I dumped gas down the throttle body. I've also presented documentation that there are two separate signals that are sent from the ICM and that for the engine to run over 400 rpm it must receive a signal from the pick-up coil to do so. I struggle with the concept that the ICM would send a spark signal and not a signal to the pcm to fire the injectors. I'll let you draw your own conclusions, but I can guarantee that I had no signal to the tbi to fire the injectors before replacing the pick-up coil (yes I had spark), but after replacing the pick-up coil, the van ran great. Although I can not totally guarantee that there was not a lose wire involved that got reconnected when replacing the pick-up coil, I highly doubt that was the situation.
I'm trying to tell you that I rebuilt my throttle body on my Transport before realizing that the pick-up coil needed to be replaced. And, after I replaced the pick-up coil, the van ran just fine. The van had spark, so I quickly and logically deduced it was a fuel related problem. However, initially, I assumed it was a fluid delivery problem and not an electrical issue. It would run as long as I dumped gas down the throttle body. I've also presented documentation that there are two separate signals that are sent from the ICM and that for the engine to run over 400 rpm it must receive a signal from the pick-up coil to do so. I struggle with the concept that the ICM would send a spark signal and not a signal to the pcm to fire the injectors. I'll let you draw your own conclusions, but I can guarantee that I had no signal to the tbi to fire the injectors before replacing the pick-up coil (yes I had spark), but after replacing the pick-up coil, the van ran great. Although I can not totally guarantee that there was not a lose wire involved that got reconnected when replacing the pick-up coil, I highly doubt that was the situation.
when I was testing my fuel injectors with the plenum off I disconnected the pigtails at the distributor to avoid ignition in the open plenum-in my face. to my surprise there was no signal to the injectors until i put the coil wires back together.
The ICM gets it's power from the Pink wire of the Pink/White harness that runs from the coil to the ICM. So no power to the ICM, then no power to amplify the pick up coil spark and send it to the ECM.
It does defy logic for a pick up coil to be bad in any fashion that it would allow spark but prevent injection since there is only one signal from the pick up coil.
I'm trying to tell you that I rebuilt my throttle body on my Transport before realizing that the pick-up coil needed to be replaced. And, after I replaced the pick-up coil, the van ran just fine. The van had spark, so I quickly and logically deduced it was a fuel related problem. However, initially, I assumed it was a fluid delivery problem and not an electrical issue. It would run as long as I dumped gas down the throttle body. I've also presented documentation that there are two separate signals that are sent from the ICM and that for the engine to run over 400 rpm it must receive a signal from the pick-up coil to do so. I struggle with the concept that the ICM would send a spark signal and not a signal to the pcm to fire the injectors. I'll let you draw your own conclusions, but I can guarantee that I had no signal to the tbi to fire the injectors before replacing the pick-up coil (yes I had spark), but after replacing the pick-up coil, the van ran great. Although I can not totally guarantee that there was not a lose wire involved that got reconnected when replacing the pick-up coil, I highly doubt that was the situation.
Only one pick up coil. Only one signal from the pick up coil to the ICM. Only one wire in which the signal is sent from the ICM to the ECM to tell it to fire the injectors. Nope no two separate signals that are sent from the ICM. Sorry.
For the engine to run over 400 RPM or under 400 RPM or at ANY RPM the ICM must receive a signal from the pick up coil. Only one pick up coil. Only one signal from the pick up coil to the ICM. No signal from the pick up coil = no spark and no injection.
