So i rebuilt my b23f in my 83 245, while reconnecting the wiring i found many bad wires. I replaced all the bad wires but the car wouldn't start. I bought a new harness reconnected and same problem.
I found there to be no voltage at the Fuel Pump Relay. The relay is a known good part. I jumped fuse 5 and 7 and the pump turns.
I have checked every sensor and they are all good.
I have spark.
I have fuel
It won't even start with the fuel pump jumper and the pump turning.
I am starting to believe the ECU is bad but the Haynes manual does not have a test procedure for the ECU.
Has anyone seen this condition before ?

 

is that car CIS/K-Jet, or is it LH-II ? I believe 83 had both.

sadly, I don't have the greenbooks for any 83's. I have the wiring diagrams for a 1984 240 which was LH-II

on the 84, there's two separate relays, one for powering the ECU, adn one for powering the fuel pump relay. pin 30 on either relay socket should be always hot. these relays are probably behind/under the glovebox, with the pump relay on the left, and the LH ECU relay on the right.

these are wired through the 25A fuse that's near the battery, inline on one of the medium gauge red wires, so if that fuse is bad, no power to the relays.

 

It has the lh II and the 25a fuse is brand new.
the system relay clicks but the fuel pump relay does not.when i switch the relays the same happens.
there is 12v at pin 87 on the system relay but not on the fuel pump relay.

 

well, pin 87 is the 'output' of the relays.

is there 12V at pin 30 of both relays? also pin 86 of the FI relay 'E' (the one on the right side) should be directly connected to battery power such that its +12 even if the car is switched off. also when the ignition is on there should be power on fuel pump relay "F" (on the left side) pin 86. (pin 86 is the + side of the relay coil)

when the ignition is switched on, the FI relay "E" should be turned on, and there should be +12V at pin 87, this provides the main power to the ECU, also the AMM/MAF.

when the FI computer (ECU) sees pulses from the hall sensor in the distributor via pin 1 of the ignition coil (which comes from the ignition computer or ICU), then it should switch on the fuel pump relay by grounding pin 85 of relay "F"

if you unplug the ECU (its under the glovebox, on the right fender wall just forwad of the passenger door hinge), relay "E" coil pin 85 goes to ECU pin 21. if you ground this, you shoudl see power on pin 9. relay "F" coil pin 85 goes to ECU pin 17, if you ground THIS with the ignition switch on, you should turn on the fuel pump.

the fuel pump relay "F" also powers your injectors and idle air control valve. the ECU grounds its pin 13 to fire the injectors. it grounds either pins 10 or 23 to jiggle the idle air valve.

ignition coil pin 1 goes to ECU pin 1 and provides the ECU with the engine timing

 

crap, I wrote a whole message about how to test the LH-II fuel system from the ECU connector (disconnecting the ECU), and I lost it by hitting the wrong button

ok, relay "E" is the fuel injection computer relay, and is the one on the left side, while relay "F" is the fuel PUMP relay, on the right side.

BOTH relays, pin 30 should always be hot (+12V battery voltage relative to chassis ground). also, pin 86 of relay "E" is always hot, while pin 86 of relay "F" is only hot if the ignition is on.

if you remove the inside panel to the right of the passenger footwell, the ECU is there. unplug the ECU connector.

take a jumper wire... pin 25 is ground. connect ECU plug pin 21 to ground, and the FI relay should turn on and there should be power at ECU pin 9

connect ECU connector pin 17 to ground when the ignition is switched on, and the fuel pump should come on.

if all that works, there's nothing wrong with your fuel pump or injection relays.

the ignition coil pin 1 is connected to ECU pin 1 and provides pulses (originating at the hall sensor, and processed by the ignition control unit) to tell the ECU the engine is turning over and what the timing is. if it doesn't see these pulses, it won't work. with the ignition on, pin 1 is probably +12V or close to it, the ICU grounds coil pin 1 to fire the coil and signal the ECU.

 

Hey thanks guys this is really helpful. I will test it after work and report back.

 

Ok Peirce the pump and the relays work based on the tests.
Does this mean my ecu is bad?

 

possibly, or there's another wiring issue.

you might unplug the ECU, and connect a test light between pin 1 and a handy ground, and verify that when you crank, that light is blinking. that is the timing signal the ECU uses to decide what to do. turn the ignition off before reconnecting the ECU.

unplug an injector, turn the ignition on, one of the pins of the plug that goes to the injector should be at 12V relative to engine ground. (use a test light or volt meter to test for juice). the other pin is likely floating so won't be meaningful. ignition off and replace the injector plug.

key off, and unplug the MAF, key on, and try to start. without the MAF, the engine should start, but will run rather poorly (idle OK but not much more). key off and reconnect MAF (NEVER plug/unplug stuff with power turned on!!). if that 'works', then its possible you have a bad MAF.

 

If the jumper wire turns the pump relay on but the ecu doesn't wouldn't that mean the ecu is bad?

 

if the ECU isn't seeing timing pulses on pin 1 the pump won't come on.

 

The test light flashes
I unplugged the maf and there is no difference. Car starts and dies immediately.
I can get it to run with the accelerator to the floor but it runs very poorly and dies immediately after my foot comes off the gas.
It acts as if timing were incorrect, but timing is verified and correct.
All timing marks line up, and distributor lives up to cyl. 1.
Firing order 1342
I have spark.
The only thing that isn't working is the pump relay with the ECU plugged in.

 

ok, thats starting to sound like a dead ECU.

Engine ECU suggests you have a -503 ECU, shared only by 83/84 cars, gonna be great fun to find one.

 

Yea it seams the only one on the world was in California i just bought it. do you know if it will have to be flashed?

 

afaik, there's no flashing of LH ECUs at all. they self-learn your engines characteristics within a few minutes of driving.

 

Good to know thanks for the help Pierce

 

so my Volvo Still won't start. i did all the tests again and everything checks out.

But it has come to my attention that when my friend scrapped my junk block, there was a sensor still in the block.
He said it was a one wire sensor pointed to the flywheel.
The wire went up to a junction block on the valve cover.
Is this a position sensor?
I can't seem to find anything in the Haynes manual.
It is a m46 Trans and there doesnt seem to be any notches on the flywheel for a hall sensor?

 

the crank position sensor on the flywheel is only used by LH 2.4 systems, on 1989+ 240's.

earlier LH II and 2.2 systems used a hall sensor in the distributor

 

I took off a cyl head off of an 84 wagon LH 2 and saw a burnt wire behind the cyl head that had a grey box that you could hook up an obd1 reader looking thing....I don't know if it was an obd1 plug but just to give you an idea. right at the place where the cyl meats the block/transmission......automatic.

 

OBD1 didn't have a plug, on Volvo's, its a little diagnostic block just forward of the left suspension tower, with a button, LED, jumper wire, and 8 numbered holes, of which only 2 and 6 are of interest to Volvo LH2.4 systems. OBD1 only existed on LH 2.4 and newer Volvos from 1989 to 1995 (turbos from 1990-95)

OBD2 came out and was mandated in 1996, and the plug HAS to be within reach of the drivers seat, most often in the center console (on my 850, its under the change tray that's between the shifter and ashtray).

 

My car has the LH II.
I am out of ideas i have no idea what is wrong.
The fuel pump relay won't click, the relay is good, fuses are good, ecu is good, fuel pump is good.
I did all the tests and it all checks out but the relay doesn't click.
I am spent.