Hi, I have an 89 240 DL that started this morning and had been running fine. After the brief start this morning (just to move the car so my son could get his car out), went back 30 min later and it would not start. Turn the ignition to crank it over and just cranks over and over.

Here is a list of what I have checked;

25A Fuse next to coil - cleaned terminals/checked continuity

Bypassed fuel relay - jumper from left side fuse 4 to left side fuse 6 - can hear fuel pump running

Checked for spark - removed plug and checked for spark - No Spark

Looking for suggestions to methodically dignose problem and not just start replacing parts.

Any help would be much appreciated.

Thanks!

did ya check to see if tbelt broke?

Yes, already checked. Thanks for the suggestion.

Fuel pump relay is on firewall behind/under glove box.Which you should remove and check/resolder joints on the circuit board. Fuel pump relay causing no spark? unlikely

Located fuel pump relay. Part of the relay actuates when ignition moved to position II. I can't check the rest as I have the Crank Sensor removed.

Thanks for the comments.

Right. You'll have spark with the fuel injection (not only pump) relay in your pocket. But it does require the 25A fuse under the hood (its wiring) to be in good shape. Sometimes invisible corrosion will not be found by unloaded meter checks and never by continuity checks.

A good method I use to check that 25A fuse circuit does it under load, and for that the FI relay, above the passenger's feet, must be present. With the key in KP-II, check for battery on the orange wire at the AMM, like this:





To check the CPS electrically, while not completely ruling it out, it helps if you see the resistance of its coil at the plug -- around 200 ohms -- by measuring where it plugs into the harness behind the cylinder head on the firewall.

If you do this methodically, you can isolate the CPS/power stage connections with methods like this:





Plug at some of these and follow up with any questions.
--
Art Benstein near Baltimore

TORTA CUBANA - HAM, STEAK, SPICY PORK, HOT DOG, EGG, JALAPENO, AVOCADO, ONIONS, QUESO FRESCO, LETTUCE AND MAYONNAISE. SERVED ON FRESH GRILLED MEXICAN BREAD...7.99

re Art B's comment below: I had an intermittent no-start (with no spark) on 1990 that's been in the barn ~ 1 year waiting for me to get around to it. Previous owner had increasingly-frequent no-starts - waiting and/or jiggling wires and it would usually start.

I replaced the CPS (insulation broken) and power stage with used ones; and I cleaned up the 25-Amp fuse unit. It started consistently all Spring & Summer to be moved around.

This AM, with the coil wire adjacent to the intake manifold, no spark when cranking but sometimes a single spark when the key was turned on. After reading through this thread, I bypassed the 25-Amp fuse. Started right up.

On closer inspection, the wire feeding the 25-Amp fuse was corroded and broken inside the insulation where it connects to the battery clamp. Cut it back ~2" and replaced the connector.

-------------------------------------------
Art "Right. You'll have spark with the fuel injection (not only pump) relay in your pocket. But it does require the 25A fuse under the hood (its wiring) to be in good shape. Sometimes invisible corrosion will not be found by unloaded meter checks and never by continuity checks."


--
240 drivers / parts cars - JH, Ohio

Hi Art, your suggestions (and pictures) really helped. Found the problem when checking the 25A fuse as you suggested under load. Fuse not getting good connection even though I had cleaned the fuse terminals and fuse holder previuosly.

Also replaced the crank position sensor due to cracked insulation and the fact it was the original and the 89 240 has 330K miles.

Thanks again to you and everyone else for their suggestions. Once again this forum saved me!

Miser that I am, I also would have replaced the crank sensor given the cracked cable sheath. Water runs into it through that broken sheath (no drip loop) and eventually the magnetized core of the sensor rusts. The sensor swells, and folks break the bracket sometimes trying to separate it from the sensor. Then you are looking at unbolting the transmission... Good call and not a waste at all.
--
Art Benstein near Baltimore

Expert: An "ex" is a has-been and a "spurt" is a little drip under pressure.

Start-Run Sequence LH 2.2 Version

1) During starter cranking, the distributor Hall sensor sends timing pulses to Ignition Control Unit (ICU)

2-a) The ICU uses these Hall Sensor pulses to trigger the Ignition Coil (– terminal) to initiate timed sparks from the coil.

2-b) At the same time, The ICU also propagates the pulses to the FI ECU, to allow FI operation (no ICU pulses means no Fuel pumping).

3-a) The Fuel Injection (System) relay (previously energized at Key On) powers the AMM and ECU. The System relay lives with the Fuel (pump) relay in the same white plastic case. The LH 2.2 "pump" relay also powers the Injectors, IAC motor/valve, and the O2 sensor heater.

3-b) When ICU pulses are received by the FI ECU, a Blue-Green wire from ECU 17 "energizes" the Fuel (pump) relay by grounding the relay coil at terminal 86-2 to run the pumps.

When all these things work, the engine runs until the Ignition is switched off, which in turn shuts down the FI system.

Determining whether or not there is spark at the plugs (2a) — and whether or not the plugs are getting gas (3b) — are good no-start "starting" points.

--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Hi Lucid, thanks for your suggestions. I have a couple of followup questions.

1) The "hall sensor" you reference above, is this the crank position sensor? If so, I have removed this and found cracked/flaky insulation. I have a new one on order. If not, where is the "hall sensor"? And since I don't have spark it makes sense this could be part of my problem.

2)I'm not certain exactly where the fuel pump relay is located, so, when I locate it could I measure the voltage at a pin (?) on the relay to verify if the FI ECU is good?

Thanks again for your help.

Do you have fuel in the cylinders. remove a plug and see?

If the plug is wet the power stage may have failed.

How old is the Cap and rotor?

Check the insulation on the crank position / RPM sensor, if cracked or missing insulation replace.

Did the relay click 2 times while turning the key, if not re-solder the circuit board on the relay or replace.

The 25 amp fuse connection to the battery may be bad due to corrosion.

Dan

Checked plugs - does not appear to have any fuel on plug(s)

Cap and rotor - replaced 1 year ago

Fuel pump - replaced 2 yrs ago. I will check relay, but, doesn't jumpering the fuses 4 & 6 bypass the relay?

Will try to locate the crank postion/rpm sensor. Any way electrically to check these, or, just check for cracked/missing insulation?

Thanks!

The only way I know to check the Crank Position Sensor is inspection. If the insulation is cracked or flaking off, it probably needs replacement. The sensor itself is located on top of the bell housing where the engine and trans meet. It has a thick black coax cable that runs to a connector on the firewall.

Thanks Jstraw. I did remove the crank position sensor and noticed it did have cracked insulation and flaking off. I'll replace that once the new part arrives later today.

Still not sure if a bad fuel relay would cause my symptoms (no spark). I would lat least like to check the fuel pump relay while waiting on my other part to arrive. Trouble is, not sure where this relay is located. Is it behind the glove box or behind the kick panel (on left or right side)?

Thanks again. I'll keep looking.