Yeah sounds like a bad ignition but I will paste something I said you should do back in early june, because it sounds like you have gremlins that can all be traced to bad under dash wiring, Here it goes.

"1. Have you pulled the felt under the steering wheel and kick panel on the drivers side and pulled off the fuse block to look for corrosion or wires with the jackets rubbed through? I would disconnect the battery, grab yourself a beer, grab a flashlight and just start to finger through all those wires under there looking for bad splices or damage. In fact look at as much of your wiring as possible. Even back by the fuel pumps and by the tank. Everywhere. Grab the wires, roll them in your fingers. Just be meticulous. "

 

adub, I actually did follow your advice and check my wiring back then. Under hood wiring had minimal rot and no shorts (but a missing oil pressure switch wire). Under dash wiring was good except for this splice, which was put on my "to address" list. The only truly bad wiring I found was for my courtesy lights, which are shorted out to the point of blowing the fuse when the door opens. The splice has since gone bad it seems, probably due to my fooling with the wiring.

Bubba:
I will check for voltage on the red/black wire as soon as I have the chance.

 

heres the image of the splice

 

So it looks like the yellow/red is jumpered to red/black ... if so the fuel pump relay has been by-passed and everything is running off the ignition switch (non-fused). So with the jumper removed its going to take a volt meter and the LH2 diagram posted to find and fix the problem masked by the jumper ... the ignition switch, relay, ECU, or short/open wire.

 

If bypassed, the car should be able to run without the relay shouldn't it? It does not. Tracing this is proving difficult, the wiring is undamaged and the ignition switch appears to function correctly. I hope this isn't an ECU problem, that will be expensive and I'm nearly broke as it is.

<edit>
Observation:
People say the pump is supposed to run for about 3 seconds when the ignition is turned to 'on'. Mine runs continuously, it stays on until I turn it off, unless the relay sticks, then it keeps running until I whack it.

 

The case contains two relays, one for the "system" and the other for "fuel". The fuel one is being by-passed, not the system. So half the relay is still being used, hence why the relay is still required to run.

The problem is that black/red wire and the ignition switch can't handle that amount of current ... notice the difference in wire gauge. And it is not fused.

And yes your pump will run continuously because it is hot wired to the ignition switch.

 

Ok, I thought it was one relay for each pump. When I hold the relay on the right closed with a pen, and turn the ignition to "start" the car runs fine.

front row
The red/black (85) wire gets 12v with the key in the on or start positions
The thick wire (87/2) gets 12v through the jumper (should be through the armature and thus (30)
(86/1) not measured
back row
(30) 12v constant
(86/2) not measured
(87/1) nto measured

 

Not that it is a smoking gun but moisture and bad or weak coil is bad mix. Take a spray bottle of water that has a fine mist and give it a quick spray. If there is an arcing point or weak connection effected by moisture that might tell you.

 

Do you ever see voltage on 87/1 (any key position)? Does one of the relays close going from key position off to on?

I would replace your relay if you haven't done so already.

 

Not near the car right now, but both relays close going from off to on. They both function as I believe they should with the exception of the right relay opening when the ignition is turned to start. If I force the right relay closed to start it, the relay will open on its own when the car is running and kill the car.

I finally measured all of the voltages, number coded in lieu of colors, roman numerals indicate ignition switch position, positions omitted indicate no voltage. Voltage without numerals indicates present in all switch positions.

85 - 0v
87/2 - III: 0.4v
86/1 - II: 12v, III: 10.5v

30 - 0v
86/2 - II: 0.085v, III: 0.12v
87/1 - 12v

I have spotted a problem, 30 should be 12v. The inline fuse is intact, when I bought the car the fuse had been hacked out and connected with spades, wrapped in duct tape. I re-soldered the connection in a proper fuse holder. The car will not run with the fuse removed, indicating that there is a deeper problem in the power getting from battery to unless I reversed the order in which I measured the voltage... argh. I'll double check when I get the chance.

 

All right, after a week of absence, I've got back on it. The measurments were indeed mixed up.

85 - II: 12v, III: 10.5v
87/2 - III: 0.4v
86/1 - 0v

30 - 12v
86/2 - II: 0.085v, III: 0.12v
87/1 - 0v

Seems to be indicating the IECU or Hall Effect Sensor. Expensive repairs but since it's running now with a new jumper and I only work a mile away I don't need the car to get to work. Waiting on funds is the name of the game now.

 

Not if you have spark. Have you tried a different relay?

 

I seem to be having the same problem you've been describing!...what a pain! It's an '87 240 with the 2.2 Jetronic fuel system.

The voltage on the relay is 12v on 30 consistently, and 0v at 85 with the ignition off and 12v with it in the on position. I have four relays I've put in there any they all act the same.

The car will start if I leave in a relay, take out the 4th and 6th fuses and jump the left sides. That makes me believe the coil, injectors, pumps, timing belt, etc are all fine.

I'm starting to think it's the ECU based on my troubleshooting and reading up on your descriptions. I'll let you know if I have any breakthroughs, hopefully it could help you out as well!

 

The ECU grounds the blue-green wire (86/2) when is sees spark. So if you manually ground that wire and everything works without the jumper ... you can be fairly confident that the ECU is bad (for that circuit).

 

I have tried a different relay, it doesn't help. Will try grounding 86/2 out and report back.

 

Massive update:
The sticking relay, the jumper, the accessories staying on. I've solved it. After months and months of my car just not being drivable my hall sensor eventually died so I had to replace it. But that didn't fix it, my car still wouldn't keep running. I did some research and found that the ECU was to blame. Bubba240, you were right, It is apparently a very common problem to have the ignition pulse detector circuit go bad in the ECU and it is a common fix to jumper the relay. I ordered a new ECU on ebay for $50, pulled the jumper from the relay and bingo! The car is running fine! No more pumps staying on, no more stalling (almost, I need a new AMM connector, the car dies when I wiggle it).

 

Congrats. Sounds like you were hosed by the PO.