Backfire Now No Start
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I still think I could be installing the distributor wrong and it's off timing. Everything is good, but it's hard to do the finger over the number 1 hole trick because it's not a lot of air coming out. When the car is trying to be started it's a lot easier to feel the air but it also makes it a little more difficult to see exactly where I'm going to line it up on the distributor since it happens so quickly.
mikestang63
SN Certified Technician
DId you follow JR's checklist? Doesn't sound like it or you don't have the expertise to do it.
Start with the basics
Take the coil wire off the cap and put a screwdriver in the end and lay the other end on top of the intake. . Tap the key and see if you have spark. If you do, then you have spark going to the distributor.
Put the coil wire back on the cap, remove the spark plug wire off the spark plug- put the screwdriver in the end of the spark plug wire and lay it on the intake. Again, tap the key but do not start it. See if you have spark. If yes, then probably you have the distributor or wires installed wrong . If not, then either the TFI, PIP is bad.
I was following his post I was just curious if it was supposed to have spark in that orientation. Thanks for the clarification
Going to get a noid light today. I really think the injectors are ok because when I pulled the plugs they all had a strong fuel smell. As far as fuel pressure it's at 40psi even while the engine is attempted to crank.
The funny thing is when I got the car the firing order was extremely weird. The car ran like that and that's the way he got it from the place that built and tuned it. I know that couldn't be right but this was the order. 4 8 1 3 7 2 6 5
Something else I want to throw out there. When I got the car there were a couple spark plug wires that were fryed from sitting on the headers. Could the spark arching may have messed up the ECM or something else?
Something else I want to throw out there. When I got the car there were a couple spark plug wires that were fryed from sitting on the headers. Could the spark arching may have messed up the ECM or something else?
The distributor is installed incorrectly and that affects the fuel injection timing.. Go back and carefully read "Putting the distributor back in and setting the timing." that I posted on the first page of this thread.
It's no longer installed like that. I just wanted to bring that up because it was the way the car came to my house. I was hoping it may help lead to finding a solution. The previous owner said he never touched the distributor so that was how the shop installed it and the car was running like that apparently.
On an 87 5.0 Mustang the EEC relay is on top of the computer. It is difficult to get to unless you have small hands and an eyeball on a stalk like a snail.
Troubleshooting no computer power.
Unless otherwise stated all voltage measurements are made with one meter lead grounded to clean, bare shiny metal for a good ground. If you do not have a good ground, you will have inaccurate results with your voltage measurements.
Step 1.) The computer is located under the driver's side kick panel. The EEC relay is mounted on top of it. The EEC relay is somewhat difficult to get at. Removing the passenger side dash speaker may help. Remove the 2 screws in the computer mount and pull the computer down. The EEC relay is mounted on a plastic push in upholstery fastener, and may be difficult to get loose. Pull it down to where you have good access to the wires. You will see 2 black/orange wires which are continuous power feed to the EEC relay. Look for 12 volts on them; they do not depend on the ignition switch being in the Run position to have 12 volt power. No 12 volts and the fuse link is bad.
Step 2.) Turn the ignition switch to the run position and look for 12 volts on the red/green wire on the EEC relay. No 12 volts then the ignition switch is bad or the ignition fuse link in the red/green wire is bad.
To check the ignition switch, remove the plastic cover from the bottom of the driver’s side dash. Then remove the plastic cover from the steering wheel. Put the ignition switch in the Run position and look for good 12 volts. No 12 volts and the ignition switch is bad. Good 12 volts and the red/green fuse link is bad.
Step 3.) Good 12 volts on the black orange wires, good 12 volts on the red/green wire with the ignition switch in the run position, no 12 volts on the red wires, check the resistance of the black green wire (EEC relay ground). Ground one meter lead and set your meter to low ohms. Measure the resistance between ground and the black/green wire: you should see less than 1 ohm.
If you see less than 1 ohm, the EEC relay is bad, or the relay socket may be corroded or damaged.
Troubleshooting no computer power.
Unless otherwise stated all voltage measurements are made with one meter lead grounded to clean, bare shiny metal for a good ground. If you do not have a good ground, you will have inaccurate results with your voltage measurements.
Step 1.) The computer is located under the driver's side kick panel. The EEC relay is mounted on top of it. The EEC relay is somewhat difficult to get at. Removing the passenger side dash speaker may help. Remove the 2 screws in the computer mount and pull the computer down. The EEC relay is mounted on a plastic push in upholstery fastener, and may be difficult to get loose. Pull it down to where you have good access to the wires. You will see 2 black/orange wires which are continuous power feed to the EEC relay. Look for 12 volts on them; they do not depend on the ignition switch being in the Run position to have 12 volt power. No 12 volts and the fuse link is bad.
Step 2.) Turn the ignition switch to the run position and look for 12 volts on the red/green wire on the EEC relay. No 12 volts then the ignition switch is bad or the ignition fuse link in the red/green wire is bad.
To check the ignition switch, remove the plastic cover from the bottom of the driver’s side dash. Then remove the plastic cover from the steering wheel. Put the ignition switch in the Run position and look for good 12 volts. No 12 volts and the ignition switch is bad. Good 12 volts and the red/green fuse link is bad.
Step 3.) Good 12 volts on the black orange wires, good 12 volts on the red/green wire with the ignition switch in the run position, no 12 volts on the red wires, check the resistance of the black green wire (EEC relay ground). Ground one meter lead and set your meter to low ohms. Measure the resistance between ground and the black/green wire: you should see less than 1 ohm.
If you see less than 1 ohm, the EEC relay is bad, or the relay socket may be corroded or damaged.
Ok. I will do that and report back. If it does turn out to be the eec relay. Where can I buy one?
The point of pulling the cap and seeing if the rotor spins exercise was to see if there was a reason you felt no air coming out on the compression stroke. You should not have had sparks flying around like Tesla owned it. I would have warned you of that if it was even a possibility.
Another question you posted needs an answer. A super charger (or turbo charger) will not change the basic function of a 4 stroke engine. It is like a fancy fan or air pump that pushes more air into the cylinders than a motor normally can suck in. With more air, you can put inject more fuel and make a bigger explosion in the cylinders during the power strokes. A super charger (when at a high enough rpm) creates a pressurized zone in the intake tract where there is usually a vacuum. But it should not interfere with figuring out Top Dead Center.
Before you replace the EEC relay or anything else, did you get any codes to download? J's list shows how to do it with a paper clip, but you might be safer with a plug in code reader. And code readers for EECIV computers (OBD 1) are pretty cheap.
Another question you posted needs an answer. A super charger (or turbo charger) will not change the basic function of a 4 stroke engine. It is like a fancy fan or air pump that pushes more air into the cylinders than a motor normally can suck in. With more air, you can put inject more fuel and make a bigger explosion in the cylinders during the power strokes. A super charger (when at a high enough rpm) creates a pressurized zone in the intake tract where there is usually a vacuum. But it should not interfere with figuring out Top Dead Center.
Before you replace the EEC relay or anything else, did you get any codes to download? J's list shows how to do it with a paper clip, but you might be safer with a plug in code reader. And code readers for EECIV computers (OBD 1) are pretty cheap.
Thanks for the clarification. This is my first fi car I've ever owned. I'm going to do the jumper test tomorrow the weather was pretty bad today.
Just so I'm on the right page I can either use a paper clip or a wire to jump the relay? Also in the picture the red line represents the two pinouts I have to jump?
Does that relay control anything else else besides just the pump? The reason I ask is because the car has an a1000 on it and I can clearly hear it every time id turn the key.Using the red dashed line in the drawing will jumper the fuel pump control ciricut to make the fuel pump run - if there are no problems in the fuel pump circuit.
Also I wanted to ask when I am setting tdc I also was using a screwdriver to know where the number one piston is. I have it at 0 now but I was just trying to test to see how long the piston stays up and it stays there a little past 0. Am I supposed to set it for right before the piston drops?
Just a thought in case my balancer is off.
The in tank fuel pump is controlled by the fuel pump relay. The external pump is probably wired directly into the ignition circuit, which is incorrect because it bypasses the computer and inertia switch control.
Computer control of the fuel pump: the stock in tank fuel pump circuit is switched on & off by the computer by providing a ground for the fuel pump relay coil. The pump turns on for 2-4 seconds when the Ignition switch is turned to Run. It does not turn back on until the engine RPM gets up past a certain point. This prevents the engine from flooding and washing all the oil off the cylinder walls.
Inertial switch in the fuel pump control circuit: the inertia switch is located behind the driver's side taillight. Its' purpose is to shut off electrical power to the fuel pump in the event of a collision. This reduces the danger of fire in a collision and protects car and driver.
If you are putting the distributor back in, or adjusting the timing, you need a timing light. That eliminates the guesswork of timing the engine. Unless you have a timing light, you will never get the timing correct. Auto parts stores may have timing lights for loan or rent.
Thanks for the explanation that makes a lot better sense of it. I'll try to jump the eec once I get home today. So in other words the external pump could be coming on either way since it might not be wired to come on with the eec relay. Is that relay a dealer part only?
The only reason I haven't got a timing light just yet was because I haven't got it to start. Isn't a timing light only useful with a running engine?
The fuel pump relay is a common auto parts store part.
fuel pump relay for external booster pump on supercharged engines
A timing light can be used with an engine that cranks OK and has good spark. It does not need to be actually running. It is easier to do with a running engine since the flash repeats more often. This makes it easier to see the pointer and where it lines up with the timing marks]
Attachments
The fuel pump relay is a common auto parts store part.
fuel pump relay for external booster pump on supercharged engines
A timing light can be used with an engine that cranks OK and has good spark. It does not need to be actually running. It is easier to do with a running engine since the flash repeats more often. This makes it easier to see the pointer and where it lines up with the timing marks]
Thank you for all the information. Would it be worth a shot of taking the tuning chip out the ecu to see if that works?
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