1988 240 Wagon - Crank No Start

cascadia · Post by **cascadia** » 21 Jul 2013, 10:02

First some background. I've owned the car three years and has been a reliable daily driver and I have performed most of the repairs and regular maintenance. I have done a complete tune up over the last two months and the car has been running/starting great. Starts on first try, smooth idle, good fuel economy, no drivability issues. Until yesterday. It cranks over but will not start. In the last few months I have replaced the spark plugs/wires, fuel pump relay, distributor cap, rotor, battery, oxygen sensor, fuel filter, air filter (K&N), several old vacuum hoses and alternator is one year old.

Here is what I know, I've got spark, battery is good, 2/3 tank of fresh gas. I can hear the fuel pumps when I jump them at the fuse panel-however I cannot when I attempt to start the car.

I've got the bentley manual and am comfortable with tools, just not sure when to go with the trouble shooting and hoping to avoid throwing money at parts that are not necessary.

Post by **jimmy57** » 21 Jul 2013, 10:19

That is a year model where the control module harness terminals are not backed up by a second piece of metal acting as a tension spring. The problem could be at the Chrysler ignition control module next to front of engine on RH side. The fuel injection control module needs ignition pulses in order to cycle injectors and to operate fuel pump relay and thus the pump. The initial pump cycle when key is on is a start up routine not relying on ignition signal.

First, push gently on the ignition module connector while someone cranks the car. If it starts then you need to remove the ignition module and use a pencil eraser to make contact with each pin in the connector area. Touch them and gently apply an orbital pressure and see if you can feel any looseness. The pins can break their solder joint to the circuit board. That can be repaired by taking cover off, clearing the protective gel off that corner of PCB, and then soldering the pins one at a time.
If no pins are loose then the terminals are suspect. The terminal could be the one at ignition CM or the other end of the RPM signal are at the FI CM. If all is good at ignition CM then plug the harness back in and see if it starts. If so then the ignition harness end needs its pins tension increased. You can use a pick and bend the fingers in that sleeve connector towards the inside.
If no luck with all this then the fuel injection CM end of the rpm signal from ignition is suspect.
I am going from memory but I am pretty sure that pin 20 is the incoming rpm signal on LH 2.2.
If you just unplug the connector, spray with WD-40 or similar and plug it back and it starts then you have the answer.

I'm assuming fuel pump noise means fuel pressure and that is usually true unless the pump is growling instead of humming. Unfortunately that car has no test port for pressure measurements. The return line hose can be removed and if fuel runs out of it when you turn the ignition during that 2 second pump run that is a somewhat reliable indication. If it pours forcefully out then the fuel pressure regulator could be ruptured.

cascadia · Post by **cascadia** » 21 Jul 2013, 10:48

Thanks so much! I will investigate and report back.

cascadia · Post by **cascadia** » 22 Jul 2013, 00:12

The ignition module connector feels solid and the car did not start while pushing it in. It behaved the same as before. I checked the vacuum hose off the fuel pressure regulator and could smell gas. I did not have time to pull the return line and check that. Would that indicate a bad regulator? Would that cause a sudden no start situation?

cascadia · Post by **cascadia** » 23 Jul 2013, 15:56

Turned out to be a faulty ignition control module. Local pick a part had one for $30 so just swapped it out instead of trying to solder/repair the old one. Ended up replacing the coil as well, the high voltage resistance was higher than spec. Started right up!

cascadia · Post by **cascadia** » 12 Dec 2019, 18:57

Six and a half years later-running into similar issue.

Crank no start. This time around I have no spark. Been running fine lately, then today would not start.

New battery, new plugs, newish rotor and cap. I can hear the fuel pump when I jump it at the fuse panel and the relay. Coil resistance is within spec. I've got voltage at the coil, starter, icm and dizzy. I tried starting fluid with no luck.

I jumped the dizzy plug (left terminal to middle terminal) with the key on and got no spark. Yet I have voltage there and at the ignition control module. Bentley manual suggests a bad ignition control module?

Another thing that I noticed, the tach does not move when cranking the engine. Is this tied into the icm?

Post by **RickHaleParker** » 12 Dec 2019, 19:24

cascadia wrote: 12 Dec 2019, 18:57 Crank no start. This time around I have no spark. Been running fine lately, then today would not start.

Are you getting a firing pulse on ECM pin# 1 (Gray wire)?
Engine wiring-1988 240 DL/GL sedan and wagon (2.3L)

cascadia · Post by **cascadia** » 12 Dec 2019, 20:02

RickHaleParker wrote: 12 Dec 2019, 19:24
cascadia wrote: 12 Dec 2019, 18:57 Crank no start. This time around I have no spark. Been running fine lately, then today would not start.
Are you getting a firing pulse on ECM pin# 1 (Gray wire)?
Engine wiring-1988 240 DL/GL sedan and wagon (2.3L)

What do you mean by firing pulse? I just went out and checked. I have 12.2volts on pin#1 with the key in the on position.

Post by **RickHaleParker** » 13 Dec 2019, 01:32

cascadia wrote: 12 Dec 2019, 20:02 What do you mean by firing pulse? I just went out and checked. I have 12.2volts on pin#1 with the key in the on position.

Pin #1 of the ECM should be 100% grounded with engine not running or cranking.
Pin #1 Opens/Floats/ goes high to fire the coil when the engine is cranking or running.

When cranking you should see a pulse train on pin#1.
Use a Oscilloscope or a computer safe logic probe.

:

One charges a Auto coil by passing current in the primary.
One fires the secondary (High Voltage Side) by interrupting the current in the primary.

cascadia · Post by **cascadia** » 13 Dec 2019, 10:14

RickHaleParker wrote: 13 Dec 2019, 01:32
cascadia wrote: 12 Dec 2019, 20:02 What do you mean by firing pulse? I just went out and checked. I have 12.2volts on pin#1 with the key in the on position.
Pin #1 of the ECM should be 100% grounded with engine not running or cranking.
Pin #1 Opens/Floats/ goes high to fire the coil when the engine is cranking or running.

When cranking you should see a pulse train on pin#1.
Use a Oscilloscope or a computer safe logic probe.

One charges a Auto coil by passing current in the primary.
One fires the secondary (High Voltage Side) by interrupting the current in the primary.

Hmm, I have neither of those tools. Nor have I used an oscilloscope since high school physics!

I presume we are trying to test the function of the ECM output to the coil?