no spark, replaced coil & ignition module, what next?

Hey guys, I'm about at the end of my troubleshooting abilities here. I was driving my '92 240 and it instantly shut off - no sputtering, struggling, etc. It'll crank and pump gas fine, but I'm not getting spark to the distributor. Swapping out coils didn't fix it, so I researched.

Testing per the "volvo no start" flow chart on volvowiringdiagrams.com gave me the following:
-Negative terminal on the coil (1 terminal) is grounded - I'm correct that it should be 12v?
-inputs to the ignition control module seem to be correct except that terminal 5 should be ~2v and I'm getting 1.2v. Is this a problem?

I replaced the ignition control module last night and still had no spark. What else can I check?

Thanks in advance.

*CODES* (per diagnostic socket #2 and # 6)??

LH2.4 FAULT TRACING *COMPLETE* "
http://www.volvowiringdiagrams.com/volvo/LH 2.4/LH2.4 Manual Complete.pdf

focus on * 7 and 9 * series cars...info DOES XFer:
http://www.volvowiringdiagrams.com/volvo/LH 2.4/LH2.4 EZ 116K.pdf

download and refer to BOTH of these:
http://www.volvowiringdiagrams.com/?dir=volvo/Ignition Systems

your symptomology implies the *usual* suspects:
1) MAIN or FUEL PUMP RELAY
2) CPS (Crank Position Sensor)
3) 25 Amp "protection fuse" fo MAINS (on the inner wing LH side by the battery *OR*
up on top of the FUSE BLOCK inside the cabin @ the left footwell panel...)

*ALWAYS CHECK FOR CODES BEFORE YOU FIRE THE PARTS CANNON....

TrickMick said:

*CODES* (per diagnostic socket #2 and # 6)??

LH2.4 FAULT TRACING *COMPLETE* "
http://www.volvowiringdiagrams.com/volvo/LH 2.4/LH2.4 Manual Complete.pdf

focus on * 7 and 9 * series cars...info DOES XFer:
http://www.volvowiringdiagrams.com/volvo/LH 2.4/LH2.4 EZ 116K.pdf

download and refer to BOTH of these:
http://www.volvowiringdiagrams.com/?dir=volvo/Ignition Systems

your symptomology implies the *usual* suspects:
1) MAIN or FUEL PUMP RELAY
2) CPS (Crank Position Sensor)
3) 25 Amp "protection fuse" fo MAINS (on the inner wing LH side by the battery *OR*
up on top of the FUSE BLOCK inside the cabin @ the left footwell panel...)

*ALWAYS CHECK FOR CODES BEFORE YOU FIRE THE PARTS CANNON....

Click to expand...

This. The parts you already replaced are the least likely cause of your no-spark condition.

Thanks for the info, guys. I'll check for codes tomorrow and read through those links.

I checked codes last night, but couldn't get any response from the diagnostic unit. Not a single flash. Does this point to anything? Pin 12 on the LH2.4 connector was grounded and should have been 12v according to the fault tracing.

When checking the RPM sensor on pin 1 by turning the key to start, the voltage only got up to ~4v. Is this normal? It said it should be 12v, but my battery was just starting to get low so the engine was cranking slower than normal.

dunnp2 said:

I checked codes last night, but couldn't get any response from the diagnostic unit. Not a single flash. Does this point to anything? Pin 12 on the LH2.4 connector was grounded and should have been 12v according to the fault tracing.

When checking the RPM sensor on pin 1 by turning the key to start, the voltage only got up to ~4v. Is this normal? It said it should be 12v, but my battery was just starting to get low so the engine was cranking slower than normal.

Click to expand...

1) the LH2.4 manual has TESTING AND REPAIR of the DIAGNOSTIC SOCKET
delineated within...
2) FULLY CHARGED BATTERY is a MUST when doing "electrical / computere
diagnostics
3) go over ALL GROUNDS and CONNECTIONS (pay attention to the PINS
INSIDE CONNECTORS and make sure THEY are *making contact")

herewith the VOLVO MANTRA:
repeat the VOLVO LEKTRIKAL MANTRA with me *ONE MORE TIME* !
1) clean / tight /correctly sized CONNECTIONS *EVERYWHERE*
2) look for "creeping blue/green CRUD *up under* insulation" on BATTERY CABLES
3) fuses scrubbed and cleaned "contacts bent SNUG (if porcelain type use the COPPER
coloured ones *NOT* the "tin ones")

here is an EXCELLENT SCREED on VOLTAGE DROP TESTING:
http://aimpartsonline.com/reduce warranties
4) alternator terminals clean snug and GROUNDED to the BLOCK side of the motor mount and safe to the alternator
5) repair / replace harness bits that are crumbly-insulated on the "notorious DEATH PERIOD for harnesses"
6) when in doubt VOLTAGE DROP TEST / check RESISTANCE ACROSS a CONNECTION
7) dielectric grease is an insulator..and that's as far as I'm gonna speak on the subject..I *DON'T* use it
on ANY electrical connection...I DO *seal* the back sides of connections to stop gas intrusion with it....EOS

once you've got the "wahrs sorted" you may proceed to testing VOLTAGE /
RESISTANCE / CAPACITANCE / INDUCTANCE / ETC....

Ok, here's where I'm at. I had the car towed to my house, did tests, checked connections, everything seemed fine. I gave up and tried starting the car again, it fired right up. So that's the worst scenario because I don't know what the problem was or when it'll come back.

I drove it around a few times, maybe 75 miles total, then it died again today in the same way. Last week I noticed missing outer insulation on the wires running to the CPS. I just replaced that a few minutes ago thinking even if it wasn't the problem, the missing insulation would be eventually. Still no start.

The main relay (white box under the glove box) clicks when I turn the key, so that's working.

It wouldn't be a blown fuse because I had the problem, then didn't have it, then had it again.

What else is there in the system? The diagnostic tests I did didn't tell me anything was wrong, other than my diagnostic port never working. What should I do next?

Also while driving my tachometer was sitting at 0 rpm. I've been having problems with it sitting still at random numbers (700-1200 rpm) for a few months. I actually just bought a new tach but haven't installed it, thinking the tach was the problem. Could this be caused by something else?

Stupid question, but did you check/clean 25a blade fuse in engine compartment? Always the first step.

Actually, I could never find it. Could it be anywhere besides near the battery/coil area?

I didn't worry much about it because the pumps still run. It's just the negative terminal on the coil is grounded.

I just tested the pumps separately, only the main pump is running. The in-tank pump doesn't run when I jumper the right side of the fuse connection without the fuse installed.

Ok, I can't figure this out. I'll recap where I'm at:

Engine cranks but has no spark. The negative terminal on the coil is grounded when it should be 12v.

-tests say everything's fine. I guess I'll redo the tests later tonight to see if anything's changed.
-coil is replaced
-ignition control module is replaced
-I took the main relay apart, both sides work
-crank position sensor is new
-I don't have a 25A fuse in the engine bay
-gas tank is 100% full, the fuel actually spilled out this morning because the pump was broken. I drove ~25 miles after filling up.
-main fuel pump runs when it should, but tank pump is not running. I'll have to make a tool to get that out for testing. The car has run without an in-tank pump before, and that wouldn't explain not power at the coil and no spark.

Does anyone have any more ideas? I've never been much of an electrical troubleshooter, but I think I've done everything I can do to test/replace...

There's one symptom that needs to be focused upon. The 0v reading you're getting at the coil. I assume you're getting 12v to the other terminal right?

If so then remove one side of the coil terminals and do an ohm check across the terminals. If you don't have any reading, then your new coil is dead.
Otherwise your coil should be getting warm during these tests with a ground on the other terminal.

If your coil has continutity - then the ignition module is shorting the coil terminal to ground continuously, which should never happen (it probably be dead). Yeah I know it's new. I've seen this happen before, (real bosch from j/y always works best).

Next the EZK module tells the ignition module WHEN to ground the coil, (and when to release it which generates the actual spark), via pin 5. If you turn the car over, pin 5 going to the ignition module should pulse constantly. Difficult to tell with a digital meter unless you've got a bar graph on it, an analog meter should be able to show something as well.

If you get no pulses from pin 5, then either your CPS is not working, or the EZK module is dead. CPS Feeds the EZK module. EZK feeds the ECU which tells the fuel pumps to run. Then again, if fuel pumps running, then CPS is ok, and EZK output stage to the ignition module is probably dead for sure.

To be certain, I'm cutting the wire for pin 5 going to the ignition module to see if that stops the ignition module from grounding the coil terminal. (You should be able to see 12v on both terminals). If so, then the EZK is the culprit. If not, then the ignition module is shorted.

PS: Your tach gets the pulses for it's reading from the switched side of the coil. Doesn't mean much since your engine would be doing about the same thing as the tach if the tach source was the problem with the tach reading.

dunnp2 said:

Ok, here's where I'm at. I had the car towed to my house, did tests, checked connections, everything seemed fine. I gave up and tried starting the car again, it fired right up. So that's the worst scenario because I don't know what the problem was or when it'll come back.

I drove it around a few times, maybe 75 miles total, then it died again today in the same way. Last week I noticed missing outer insulation on the wires running to the CPS. I just replaced that a few minutes ago thinking even if it wasn't the problem, the missing insulation would be eventually. Still no start.

The main relay (white box under the glove box) clicks when I turn the key, so that's working.

It wouldn't be a blown fuse because I had the problem, then didn't have it, then had it again.

What else is there in the system? The diagnostic tests I did didn't tell me anything was wrong, other than my diagnostic port never working. What should I do next?

Click to expand...

*HOW* do you *KNOW* the relay is WORKING...you *KNOW* that is is CLICKING that
doesn't mean it is WORKING!

a FLAKY FUSE CONNECTION will come and go...go back...scrub the FUSE PANEL
CONTACTS and replace dodgy fuses

the *SECONDARY LOCATION for the *25 Amp FUSE* is the TOP OF THE FUSE
PANEL in the left footwell....

FIX THE DAMNED DIAGNOSTIC SOCKET and then pull the codes...all of the DIAGNOSTICS
included in the LH2.4 Manual COMPLETE *INCLUDE* both REPAIR OF THE DIAGNOSTIC
SOCKET *AND* "alternative means / methods" of gaining the info you need to do a
proper diagnosis of the fuel control system....I have previously forwarded the URL's for
ALL of the IGNITION SYSTEMS DIAGNOSIS MATERIAL you'll EVER NEED...if you have
NO SPARK you have to start there WITH THE BASICS (which include such things as
measuring the resistance of ALL *secondary spark conductors* / measuring the resistance of
the coil / checking the cap and rotor CAREFULLY for "carbon tracks" - Indicating an ALTERNATIVE
PATH TO GROUND for the spark energy / etc....)

DIAGNOSTICS are one of TWO AREAS in the automotive field that cause untold aggro
and the waste of inordinate amounts of shop time due to lack of procedural FOCUS
and the failure to DOCUMENT test results along the way...ASSumptions are INVALID
in diagnostics - test RESULTS TO SPEC are required to dis-allow ANY "part / conductor /
sensor / input-output signal / and so forth from being "the cause of the problem"....
(the OTHER area is ELECTRIC / ELECTRONICS with very similar "failure modes"... )

I am *NOT trying to "beat you up here"*....intermittent problems are SUPREMELY
EXASPERATING in their manner of presentation...you just have to "knuckle down"
and work smarter than a collection of 20 year old wires and circuits....you CAN DO THIS
*don't quit* (too many wonderful old cars get trashed due to some stupid quirk that went
un-detected by an erstwhile acolyte who misses the primum movens due to a momentary
lack of focus)....hang in there man...we are ALL pullin for ya to solve this....

I swear I only clicked it once. Double post.

Do what Mick says and you will find the problem.

Clicking relay =/= working relay.

*HOW* do you *KNOW* the relay is WORKING...you *KNOW* that is is CLICKING that
doesn't mean it is WORKING!

a FLAKY FUSE CONNECTION will come and go...go back...scrub the FUSE PANEL
CONTACTS and replace dodgy fuses

the *SECONDARY LOCATION for the *25 Amp FUSE* is the TOP OF THE FUSE
PANEL in the left footwell....

Click to expand...

First off, he has power to the ECU and to the ignition module. The fuel pump would not operate without it, and neither would the ignition module ground out the coil, unless it has a direct short in the output stage.

Second, if you look at the schematics for this year, the 25 amp fuse on the left fender (which supplies the fuel pump relay) does not exist in 1992. That duty has been transferred to fuse #6 in the fuse block (your secondary location). Since he has at least one pump running... that fuse is good.

FIX THE DAMNED DIAGNOSTIC SOCKET and then pull the codes

Click to expand...

What could possibly be wrong with the diag socket? It's never used... It's just wires connected to sockets... I mean - like wear and tear? It's possible he may not have done the activation procedure correctly.

THEN AGAIN - the ecu would never know about a failing power stage like this as there's no feedback other than the CPS (monitoring RPM), and what else? Not much left there. So diagnostic codes might indicate a misfire. like no kiddin. We already know that, it has no fire at all. (Look at the schematics, ecu has no way to know this).

measuring the resistance of ALL *secondary spark conductors* / measuring the resistance of
the coil / checking the cap and rotor CAREFULLY for "carbon tracks" - Indicating an ALTERNATIVE
PATH TO GROUND for the spark energy / etc....)

Click to expand...

He can't even get a single spark because the terminal on one side of the coil is shorted to ground. That ground has to be released in order to generate a secondary 'spark'. All this secondary stuff - is secondary to that, the primary coil.

Give the dude a break, he's learning and he's onto something. He measured the culprit several posts ago. Just didn't realize he found the problem already.

the effort here is TWOFOLD:

1) to get the car running RELIABLY
2) to inculcate DIAGNOSTIC practices....

the OP is *GETTING THERE* ...were he following a FACTORY GREENBOOK
he would have had the *coil test result* NAILED THE FIRST TIME OUT...he
missed it by not TRYING TO FIND THE *SYSTEMIC RELEASE OF THE
COIL GROUND* ( as YOU have pointed out.... )
I'm NOT into spoon feeding anymore...those who choose to put forth the effort
will out in the end....the "fix it for me" crew will dodder on some to success and
some to a "crushing event"....I'd rather guys like the OP *get it* when they do an
ORDERLY PROCESS and DOCUMENT their progress and EVENTUAL SUCCESS
*that* is the intended function of the "flow charts" and "following the scripts"....

hand a man a fish and you feed him for a day....TEACH a man to fish -
and he'll spend the rest of his life floating around the lake...drinkin beer and drowning
worms.....

BTW...fixing the "diagnostic socket" is a HUGE HELP in fuel system diagnosis (not only
for the CODES it presents but also the FUNCTIONAL TESTING you can run using one of
the OTHER sockets.....just sayin)....as the pro's know ; "*NEVER* too much info when dealing
with an intemittent..." (learning the skill of separating the wheat from the chaff is the *ARTISAN*
part of technical work n machinery....)

and I am a FARTIST!

I just noticed this post you made:

Pin 12 on the LH2.4 connector was grounded and should have been 12v according to the fault tracing.

When checking the RPM sensor on pin 1 by turning the key to start, the voltage only got up to ~4v. Is this normal? It said it should be 12v, but my battery was just starting to get low so the engine was cranking slower than normal.

Click to expand...

You mean you measured nothing on pin 12, ie 0v. On the schematic this goes to the diagnostic connector pin 2. How did you actually measure pin 12? VOM probe punch thru to the wire itself?

I assume you did the same thing to check the voltage source for the RPM Sensor. This is voltage failure everywhere.

While I'm not fully aquainted with the interoperability between the ecu and ezk, I've never known a volvo to date that would hold one side of the coil to ground intentionally just sitting there. You could have a partially failed ecu, and a fully failed ezk or ignition module.... or maybe all 3... extremely unlikely but anything's possible.

No voltage from pin 12 would definitely cause your diagnostic code reading attempt to fail.

Just a quick thought. The ground you see on the coil negative: it should not be there, of course, except when the coil is being discharged. Simply remove the plug on the ignition amplifier. Is the ground still there? I bet it is, since you replaced that amplifier already, and you probably had a good look at its connector and the white/red wire. Now, think about the tach wiring. That also connects to the coil negative. Try pulling the wires going to the coil and find out which one is grounded. Maybe it is the wire going back to your dash and the tach, pinched somewhere?

Of course, I have no idea how you determined a ground exists. Believe me, car mechanics have all sorts of different ways to approach electrical trouble shooting.