It just won’t start

[Bstow1]

I am in need of help, which is why I came here. I am working on my 1978 124 convertible 1800, which has been in my garage since March. I was out on a short springtime drive, and a 1/4 mile from the house, she just quit. Would turn over strong, but would not restart. Pushed it back to the garage and it’s been sitting ever since. Finally had time to dive into it recently. Still cranks strong, no start. I have replaced spark plugs and fuel filter. I have verified timing setup to the best of my knowledge…marks on cam pulleys line up with pointers, mark on crank pulley set to long dash on front cover, all while cylinder #1 (farthest forward) is at TDC. Verified spark on plug from #1. Fuel is pumping. What am I missing? I’m not sure where to go next…carburetor? Ignition? I have a slope from my garage into a pond, and I’ve almost given her a good shove a couple of times. Any help would be appreciated.

[Bstow1]

Some pics…
https://share.icloud.com/photos/0c39Y8l ... zmD_LclGjg

I’ve taken plugs, wires off and replaced…did I screw up the firing order? 1, 3, 4, 2 with #1 being the farthest forward?
Has my electronic ignition gone bad?
I turned the distributor, is it supposed to face #1 or #4?

I’m a head case, I’m doubting everything that I’ve done.
Maybe I need professional help with my head (mine not the Spider’s).

[bobplyler]

Sounds like ignition. To check, take an old spark plug, put a spark plug wire on it, lay it on the top of the engine, and crank the engine. If no spark, then that's where to start.

[Bstow1]

Thanks, Bob. I’ve already done that, I have strong consistent spark

[bobplyler]

When the timing marks on the cams are lined up, the distributor rotor should be pointed to the 4 spark plug wire.

After cranking, you should be able to see some gas going through the carb when stepping on the gas. This is from the accelerator pump.

You can put the ignition timing light on either 1 or 4, because the cams go half the speed of the crankshaft.

Do you have a timing light? I just bought this one, because you don't have to find a +12V source under the hood
https://www.amazon.com/Performance-Tool ... 002KS72GA/

[Nut124]

When all the timing marks line up, #4 cylinder is firing. Need a timing light to set ignition timing.

I do not understand what stopped it and how the firing order could have gotten mixed up.

Set it to fire at #4 and pump the gas. If you have spark it should try to start.

[18Fiatsandcounting]

I have to ask a stupid question, but are you just out of gas?

Here's what I would do:

1) Peer into the barrels of the carb with a flashlight as you work the throttle. You should see a squirt of fuel from the accelerator pump jet. If you see nothing, it's a fuel issue like a bad fuel pump (mechanical) or you lost power to an electric fuel pump. Or a blockage in the line.

2) Squirt some starting fluid down the barrels of the carb and then see if it tries to start. If it does, that confirms that it's a fuel problem. If still nothing, then recheck the ignition.

And yes, with the two cam pointers lined up and the engine at TDC on #1, the rotor in the distributor should be pointing towards the #4 spark plug.

A remote possibility is an issue with the dual point ignition system that the '78 spider came with, but that wouldn't square with what appears to be an aftermarket electronic ignition system.

-Bryan

[Bstow1]

**UPDATE**
Finally had time to work on the 124. After several hours of messing around and prayer, God spoke to me and told me to swap the plug wires. I’ve literally checked everything with no success in getting this thing started, so why not. I started moving the plug wires down the line one position at a time, and WHAALAA! It started!! I need help, my firing order is not 1,3,4,2. … but 2,1,3,4. Which is the same order, but…rotor is facing complete opposite of #4 at TDC. ???? So, I timed it up with a light, still showing timing on wire 1. About 8 degrees at idle, 35 or so at 3800. Sounds great. Problem is under load, while actually driving, stutters and jumps over about 3000. Do I have a vacuum leak? Carb issues? I’m so happy to have it running again, but now I want more. I have learned a lot and thank everyone for their support. I want to learn more and fix this, any help would be appreciated.

[18Fiatsandcounting]

I need help, my firing order is not 1,3,4,2. … but 2,1,3,4. Which is the same order, but…rotor is facing complete opposite of #4 at TDC. ????

It's easy to get it a bit tangled up. The firing order is 1-3-4-2 but the only requirement is that 1 follows 2, 3 follows 1, 4 follows 3, and 2 follows 4. So, the firing order is 1-3-4-2 or 3-4-2-1 or 2-1-3-4 or 4-2-1-3-4-2-1-3-4-2 etc. The engine doesn't care.

When the engine has the #1 cylinder at TDC, the engine has two possibilities for which spark plug should fire. If the holes in the cam pulleys are lined up with the pointers, the engine is set to fire on spark plug #4. If the holes in the cam pulleys are 180 degrees away from the pointer, it's set to fire on spark plug #1.

It sounds like you got the timing pretty close, otherwise the engine wouldn't run. As for the sputtering at higher rpms, the two most likely causes are: 1) the distributor timing is not advancing as it should, or 2) your electronic ignition has issues.

A question: When you say the engine "jumps" over 3000 rpm, do you mean the tach needle jumps? Jumpy tach needles are often a sign of an ignition system that isn't set up right. Bad points, or if you have electronic ignition, the magnetic pickup inside the distributor is out of adjustment or is failing. Or the Ignition Control Module (ICM) is going bad. Possibly a weak coil as well.

-Bryan

[Bstow1]

Thanks, Bryan.

By jumping, I mean the vehicle. It’s sputtering enough to make the car jerk back and forth while driving.

Sounds like I need to investigate my distributor advance and the electronic ignition.

[18Fiatsandcounting]

"Jerking" of the engine under load or at higher revs can also be caused by an intermittent fuel supply. A few possibilities:

1) Weak fuel pump, or more likely, a small leak in the hose from either the input to the pump or the hose going into the connection at the tank. If air leaks in, the fuel pump will draw in the air, and the engine can sputter due to lack of fuel.

2) Another possibility is that your float bowl is not vented to the air, so when the engine tries to draw in a lot of gas, the vacuum causes the fuel supply to the jets to be shut down.

3) A sticking float valve is also possible although not very common.

-Bryan