So I found out that my fuel like was rusted, so I upgraded it with 3/8" hose and line all the way to rail and rewired the pump at the same time. I go to start my car and think I have no spark. No big deal, I had already ordered a COP. So now that the COP is verified working and sparking I have no fuel in the cylinder but getting fuel to the rail. I am thinking something I did stopped the injectors from working. I don't understand this as I only did the fuel pump and rewire didn't do anything else under the hood. The MPI fuse is fine as are all the others. What controls the injectors? Is it the CAS or ECU? I don't think I would get fuel while cranking (I am) if the CAS wasn't working right? The car was running fine before I did the lines and repair.
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HHIVR4
Well-known member
Have you checked the ecu for cap leak damage?If not check there first.
1941Galant
Well-known member
To test the CAS you can put the key in the on positon, pull the CAS off, and spin the sensor (the part that goes into the intake cam), if you can hear/feel the injectors firing, then the CAS should be good. The only downside is that you will have to reset the base timing.
BoostedAWD91
Well-known member
if u can get your hands on a Noid light, that will tell you if your injectors are firing
Excuse my noobness, but what is a Noid light? I used a test light and am getting constant positive on one of the wires going to the injectors. Using the light across the plug doesn't do anything, but I don't know if that would prove anything or not.
The fuel pump works off the CAS signal when the engine is cranking correct? I am getting a good amount of fuel coming out of the line when the engine is cranking. There is no fuel when the key is in the on position though. I will check the ecu, I really hope its not that....
The fuel pump works off the CAS signal when the engine is cranking correct? I am getting a good amount of fuel coming out of the line when the engine is cranking. There is no fuel when the key is in the on position though. I will check the ecu, I really hope its not that....
Wizardawd
Well-known member
Im going with CAS, like he said. Turn it by hand and check. If you're getting fuel, the ECU is more than likely not the culprit.
Wiz
Wiz
Ok, but doesn't the CAS run the fuel pump when cranking? I want to know because that would rule it out as a problem as I am getting gas flow with cranking, but not with the key in on position. The other reason I don't think its the CAS is I didn't touch it when I was doing the fuel line and rewire. I will try the turning the CAS method though. I'm wondering also about MPI relay being stuck, or just died. Where is that located? Thanks,
grocery_getter
Well-known member
You said you have spark? If you are sure you have spark then your CAS is ok. You won't have spark if your CAS is dead.
You should have 12v on one of the injector legs. The injector is getting 12v powered thru the white resistor block on the firewall. The other leg on the injector is ground, that is activated by the ECU. The ECU provides ground signals to the injector to close the circuit and fire the injectors.
So you have a good CAS, and no firing signal from the ECU. Trace it back to the ECU pinouts for injector 1-4 firing signal and see if you can get a ground firing signal there. Use a multitester with the positive probe on the battery 12v and the neg probe on the injector 1-4 ECU pinouts.
The MPI relay is a big gold looking relay under the glove box, right next to the ECU. If your MPI relay is bad you won't have fuel pump and you won't have spark.
You should have 12v on one of the injector legs. The injector is getting 12v powered thru the white resistor block on the firewall. The other leg on the injector is ground, that is activated by the ECU. The ECU provides ground signals to the injector to close the circuit and fire the injectors.
So you have a good CAS, and no firing signal from the ECU. Trace it back to the ECU pinouts for injector 1-4 firing signal and see if you can get a ground firing signal there. Use a multitester with the positive probe on the battery 12v and the neg probe on the injector 1-4 ECU pinouts.
The MPI relay is a big gold looking relay under the glove box, right next to the ECU. If your MPI relay is bad you won't have fuel pump and you won't have spark.
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Thats the other reason I thought I had a good CAS. I forgot to mention that the car will run fine if I pour gas in the cylinders for a few seconds, so everything else working. I'll try the testing of wires at the injector plug and ECU. Thanks.
Gimpin
Well-known member
pull the fuel rail off pull the injectors out of the head ... put the injectors in the rail sticking up with them still plugged in and have someone crank the car ... you should be able to see the injectors spray in the following order 1-4-3-2 make sure they are all getting a good mist type spray and not a stream or drible ... this will help you narrow down if your injectors are fireing and that they are not clogged
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^^^ I will try that once I get the ECU back in the car. I tested one of the injector plugs and I am getting a constant 12V on one wire. When I either put a test light on both sides of the plug or put the test light between positive battery and one side of the plug there is no blinking when I crank the engine. I know this isn't the best way to test, but thats all I have right now.
I am beginning to lean towards blown MPI relay, but its just a gut feeling. This is what the caps look like. I think they were replaced, but I don't know if that is replaced caps or acid burn. The guy I got it from had replacing caps info from VFAQ in the paperwork he gave me. What do you guys think?
I am beginning to lean towards blown MPI relay, but its just a gut feeling. This is what the caps look like. I think they were replaced, but I don't know if that is replaced caps or acid burn. The guy I got it from had replacing caps info from VFAQ in the paperwork he gave me. What do you guys think?
Ok, I can hear my injectors working, but not spraying. Hmmmm... So I do some checking and the stock FPR is dead. So I drill it out just to see if the injectors with work, and they do. The car runs terrible, and the plugs are black, but I proved that the everything works. Here's the annoying thing - I'm 2hrs way from Street Tuned /ubbthreads/images/graemlins/banghead.gif so I can't just get the whole AFPR kit. I'm stuck with getting a new stock one just to make a 2 hr drive /ubbthreads/images/graemlins/banghead.gif /ubbthreads/images/graemlins/banghead.gif It seems people here have never heard of the name Aeromotive....
