I have a 1991 Volvo 240 wagon that does not want to start. It would normally start and run really rough and eventually die. Now it wont start at all. I replaced the air mass meter and the rpm sensor but with no luck. I have been testing the ignition coil and the powerstage and this is what I have found.

Testing in situ gives the following recommended readings. (a) Terminal 4
to ground and/or ignition coil terminal 15 should read 12Volts.
(b) Terminal 5 to ground with starter motor operating should show a pulsating
reading between 0 and 2 Volts. (c) Terminal 1 to coil terminal 15 should read 0.6
to 1.2 Ohms resistance. (d) Terminal 1 to king lead connector on coil (HT
terminal) should read 6.5 - 9.0 Ohms resistance. (e) Terminal 2 to ground
should read 0 Ohms resistance. (f) Ensure that screen (shield) of screened
cable is connected to Terminal 3. If (c) reading is too low replace coil. If
(c) is too high, check wire between Terminal 1 and coil terminal 15, replace
or repair if necessary. If (d) is too low or too high replace coil. If (b)
is OK but unit is not working try replacement unit. The above information
comes from the EZ 116 K Ignition system Green Book.

My Tests:

A) 12V
B) 0V (No Pulse)
C) 1.1 Ohms
D) 0 Ohms
E) 0 Ohms
F) UNSURE

Luckily I had access to another Volvo 240 Sedan that I was able to compare a couple of issues on. Test (B) on the Sedan came back normal = 0 to 1.8V. However I was not getting any Pulse on the stalled wagon. As far as test (D) goes I was unable to get any reading from it. I thought this was strange and tested the good sedan and got the same no reading, however the sedan runs fine so I might be doing something wrong. What I did was connected the positive lead of the tester to terminal 1 and the negative to the top of the coil (King Lead?). I also swapped the tester lead to see if there was any difference but it showed none. I thought the problem would be regarding test (B) as that was the only real difference I could find between the cars. I tried swapping out the ignition coil of the good sedan to the stalled wagon but same results. In the test procedure it says if (B) is OK but unit is not working then replace. However it does not state what to do if test (B) fails. As far as test (F) goes I am not sure what it is asking for. If it is saying make sure that terminal 3 is plugged into the wire harness then I have done that. Any suggestions would be greatly appreciate, as I am wondering what to try next. I want to get my wagon up an running as soon as possible.

Thanks,
GARRETT

 

Has the crank position sensor been replaced? That is what generates the pulses for the power stage.

 

Pretty sure he's calling it an rpm sensor and has replaced it. Have you attempted to pull codes? Not sure if 91 had that stupid fuse by the battery or what it controls besides fuel injection but I know it's thrown me a time or two. And...sure, a bad power stage will cause some funky readings.

 

I missed that

 

Still, it would be good to know if it was used or new...sure sounds like a crank sensor! Glad to see folks pulling out their DVM and taking readings. Still, what I have found often is 2 or 3 sensors all working within the approved parameters (usually on the low side) and yet have poor performance. It's as if the combined low performance multiplies the issue.

 

Thanks for the reply's guys, (Hey that rhymed)

The problem I believe why it wont start is because there is no spark to the coil. So I have been troubleshooting because I have replace every component with a know working one from the coil back. Correct me if I am wrong but I believe that the ignition sends current to the ICU then onto the crank position sensor, to the powerstage, then to the coil. With this in mind I have replace the ICU, powerstage, and the ignition coil with working parts. I have also replaced the crank position sensor with a new one however there is a possibility that it I received a non working part.

Is there some way to test the CPS to ensure it is working properly?

Terminal 5 on the powerstage wire harness was tested but I am not sure what that component it is relating to. However I was able to do the same test on a working 240 and my meter showed it at 0V and when cranking went to about 1.8V. This is why I suspected my problem might have to due with this particular reading.

Also I have replace the Fuel pump relay and the pumps engage when I turn on the ignition, this is why I suspect it is some type of an electrical issue.

As far as the codes go yes I did get some after about a four hour long trip. I checked the codes and I was getting two (can't remember the numbers). One was oxygen sensor faulty. Which is understandable because there isn't one. The guy I bought it from must of cut out the catalytic converter along with the O2 sensor. DUMB!! I know and I will replace it soon but I don't think this would cause a no start.

The second code was erratic rpm signal or something like that. I was unsure of the cause on this one. However once I parked it for a day or two it did not want to start up again. Since then I have replaced the air mass meter, fuel pump relay, ignition coil, powerstage, ICU, and the air box thermostat, which by the way froze in the open position allowing exhaust to flow through the air box and destroy the air mass meter in the first place. Mind you this is before I got the car. Any suggestion would be greatly appreciated

Thanks for you help!

 

Alright sorry I haven't gotten back to you sooner, but on the contrary she is running! I cleans the ground contacts really well, then I checked to make sure the Crank Sensor was getting power and had ground. Since that checked out I make sure I was getting battery voltage at the powerstage as well as ground. From there I went to the ignition coil and was getting power off of that as well.

I went ahead and tried to start her and she wanted to but would not catch. I heard a clicking noise when I tried to start it and traced it back to the ignition coil. It was arching between terminal 2 and the top terminal. So I switch it out the the working sedan volvo and tried the arching ignition coil on the working sedan and it ran fine with no arching. So I took the other ignition coil that was from the working sedan and put it on the wagon and she started with no arching on the coil (weird).

However the problem is not yet solved, She run but whenever I give it gas it just revs up and then dies. I am thinking it might have to do with the Mass Airflow Sensor. Since this was not working before I replaced it but there is a possibility that it is also DOA (like the Crank Sensor). Is there any test that can be performed on it to insure it works. I checked the voltage and ground at the wire harness and that checks out. I thought I read somewhere that you can do an ohms test on terminal 2 and 4 and should get a reading at about 4 ohms. I tried but was only getting around 1.8. However on the old Airflow Sensor I got 0 ohms. I would greatly appreciate any help you could offer.

Thanks,
Garrett

 

The AMM terminal 2,4 ohms test will only check if the heated wire inside is broken. See if the car will stay running (although rough) with the AMM unplugged.

 

With the Air Mass Meter unplugged I start the car then it dies and then I try to start it again and it will idle. When I rev it up it dies. With the Air Mass Meter plugged in it starts first try and fluctuates rpms until it finds a smooth idle. However the same effect when I rev it or give it some gas the rpm's go up then come down and it dies. It does sound like it runs better with the air mass meter plugged in, I just wish there was a way to check it to make sure. Do you think the stalling could be due to a clogged fuel filter? Would a bad O2 sensor cause this? I would appreciate any input.

Thanks,
Garrett

 

I would re-install the o2 sensor next.