Full Version: Diagnostic Question
Happy Labor Day everyone! Hope you're having a great holiday weekend, or at least plan to. Next weekend my wife is giving me the entire weekend to work on my 914 so I"m definitely taking advantage of this free time. I'm planning to finish replacing all the fuel lines and bleeding the brakes. I'd love to drive the car; however, the last time a battery was hooked up NOTHING worked. The fuel pump came on, but that was it. Any ideas as to where I should start troubleshooting this? Is there one relay or fuse that I should check? Thank you for any assistance you can provide!
Check:
All fuses
Relay board circuitry (continuity) and round relays (swap them with headlight motor relays to check)
All chassis grounds, including the FI harness at back of engine case.
Report back.
All fuses
Relay board circuitry (continuity) and round relays (swap them with headlight motor relays to check)
All chassis grounds, including the FI harness at back of engine case.
Report back.
I'd forego the fuel lines and brakes since you only have one long weekend and the most urgent thing is getting it to fire.
With a freshly charged battery, does it turn over when you hit the starter? That's the first thing to deal with. If it cranks but doesn't fire, that's very different than if it doesn't crank at all.
With a freshly charged battery, does it turn over when you hit the starter? That's the first thing to deal with. If it cranks but doesn't fire, that's very different than if it doesn't crank at all.
Sorry for the late reply, I realized that she's going away this coming weekend, not Labor Day weekend.
I want to finish the fuel lines because the old ones were leaking BADLY. They are pretty much complete, just have to re-install the tank and connect two lines.
I will try what you said with the relays, ground, etc and report back. the last time I did crank it over it cranked fine but did not fire. At that time the fuel lines were leaking, the gas wasn't fresh and I'm pretty sure the spark plug lines were not connected in the correct spots.
I will fire it up this weekend and see what happens.
Thanks again!!
I want to finish the fuel lines because the old ones were leaking BADLY. They are pretty much complete, just have to re-install the tank and connect two lines.
I will try what you said with the relays, ground, etc and report back. the last time I did crank it over it cranked fine but did not fire. At that time the fuel lines were leaking, the gas wasn't fresh and I'm pretty sure the spark plug lines were not connected in the correct spots.
I will fire it up this weekend and see what happens.
Thanks again!!
QUOTE(Rand @ Aug 31 2018, 02:59 PM) 
I'd forego the fuel lines and brakes since you only have one long weekend and the most urgent thing is getting it to fire.
With a freshly charged battery, does it turn over when you hit the starter? That's the first thing to deal with. If it cranks but doesn't fire, that's very different than if it doesn't crank at all.
The car cranks but does not fire. How do I know if it’s getting fuel and spark? Before it was easy to tell cause it was leaking from all the fuel lines.
QUOTE(sjhenry1075 @ Sep 8 2018, 04:00 PM)
QUOTE(Rand @ Aug 31 2018, 02:59 PM)
I'd forego the fuel lines and brakes since you only have one long weekend and the most urgent thing is getting it to fire.
With a freshly charged battery, does it turn over when you hit the starter? That's the first thing to deal with. If it cranks but doesn't fire, that's very different than if it doesn't crank at all.
The car cranks but does not fire. How do I know if it’s getting fuel and spark? Before it was easy to tell cause it was leaking from all the fuel lines.
Take a can of carb cleaner and spray it in the intake. Then try to start it with your foot flat on the floor. If the ignition system is working, the car will either try to fire or fire up and die.
If it doesn't fire, start looking at the ignition system. Pull the coil wire and hold it close to a ground. Then crank it and look for a spark. If you see one, replace the cap and rotor. The rotors can sometimes burn a hole through them and dead short the ignition to ground.
If it has no spark at the coil wire, check the points/condenser/electronic ignition system. I just recently found a bad condenser that caused a no start condition on a car my father owns.
If you get spark to the plug wires, try a new set of plugs and repeat the carb cleaner test.
If the ignition system is OK, then we can start on the FI.
QUOTE(ClayPerrine @ Sep 8 2018, 10:14 PM)
QUOTE(sjhenry1075 @ Sep 8 2018, 04:00 PM)
QUOTE(Rand @ Aug 31 2018, 02:59 PM)
I'd forego the fuel lines and brakes since you only have one long weekend and the most urgent thing is getting it to fire.
With a freshly charged battery, does it turn over when you hit the starter? That's the first thing to deal with. If it cranks but doesn't fire, that's very different than if it doesn't crank at all.
The car cranks but does not fire. How do I know if it’s getting fuel and spark? Before it was easy to tell cause it was leaking from all the fuel lines.
Take a can of carb cleaner and spray it in the intake. Then try to start it with your foot flat on the floor. If the ignition system is working, the car will either try to fire or fire up and die.
If it doesn't fire, start looking at the ignition system. Pull the coil wire and hold it close to a ground. Then crank it and look for a spark. If you see one, replace the cap and rotor. The rotors can sometimes burn a hole through them and dead short the ignition to ground.
If it has no spark at the coil wire, check the points/condenser/electronic ignition system. I just recently found a bad condenser that caused a no start condition on a car my father owns.
If you get spark to the plug wires, try a new set of plugs and repeat the carb cleaner test.
If the ignition system is OK, then we can start on the FI.
Thank you for the help! I’ll do those and get back to you
QUOTE
How do I know if it’s getting fuel and spark? Before it was easy to tell cause it was leaking from all the fuel lines.
I hope that was meant as humor.
Get someone who knows something to help you in person. You are way over your head and that's not the place you want to be when gas is leaking.
Fuel:
Pull the injectors and put them into jars (while still connected so you can crank the engine) and see how much fuel is getting through them.
Spark:
Pull a plug wire off, stick a new plug into it, ground it against the case, and look for spark when cranking.
If you are uncomfortable with any of that, get help.
QUOTE(Rand @ Sep 9 2018, 04:27 PM)
QUOTE
How do I know if it’s getting fuel and spark? Before it was easy to tell cause it was leaking from all the fuel lines.
I hope that was meant as humor.
Get someone who knows something to help you in person. You are way over your head and that's not the place you want to be when gas is leaking.
Fuel:
Pull the injectors and put them into jars (while still connected so you can crank the engine) and see how much fuel is getting through them.
Spark:
Pull a plug wire off, stick a new plug into it, ground it against the case, and look for spark when cranking.
If you are uncomfortable with any of that, get help.
My comment about the fuel leak was in regards to my experience when I first received the car, turned it over and found the fuel lines were leaking at the injectors, which have since been replaced. The injectors have been rebuilt by that guy in the mid-west referred to me by people on this forum. I’ve replaced all fluids, plugs, wires, rotor and cap, so I’m thinking it’s one of two things: the distributor, or more specifically the points (spark at coil wire), or I accidentally reversed one of the fuel lines.
I appreciate the follow-up. When I hear fuel lines I tend to default go to the ones that run through the tunnel (a thing with 914s). Sounds like you are on the right track to troubleshoot.
Is this D or L jet?
Wondering what evidence steered you towards specific components. The fundamentals of fuel and spark are very important. You need to know whether the spark plugs are sparking when you crank the motor. You also need to know whether fuel is coming out of the injectors when you are cranking. From your posts I can tell that you are getting familiar with the motor, and can replace components. I cannot tell if you know how to determine whether sparks are happening and fuel is spraying. These are measured pretty directly. A few more posts will help quite a bit.
QUOTE(worn @ Sep 11 2018, 09:40 PM)
Wondering what evidence steered you towards specific components. The fundamentals of fuel and spark are very important. You need to know whether the spark plugs are sparking when you crank the motor. You also need to know whether fuel is coming out of the injectors when you are cranking. From your posts I can tell that you are getting familiar with the motor, and can replace components. I cannot tell if you know how to determine whether sparks are happening and fuel is spraying. These are measured pretty directly. A few more posts will help quite a bit.
It's a D jet. I was always told to start with the cheapest parts. I have spark at the coil, and continuity for the coil wire but nothing past that. The car hasn't been touched in about 15 years or so, so I'm assuming the distributor, points and condenser are old. I'm sure they need to be adjusted anyway, and they are very cheap, so I'm going to replace the points and condenser. (I already replaced the cap and rotor).
As far as fuel is concerned, I did just replace all the fuel lines so I'm thinking I could have flipped the return and supply.
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