2000 Volvos S80 misfire

draser · Post by **draser** » 21 Apr 2015, 13:51

You mean the air duct going to intake manifold? Is there an obstruction in there?

jaru · Post by **jaru** » 21 Apr 2015, 14:43

Hello, I might be using the wrong terms. It is the metal manifold that on one side connects to the ETM and on the other side it connects to the engine. thanks

jaru · Post by **jaru** » 21 Apr 2015, 14:47

I is what supplies the air from the etm to the engine. I just removed the top cover

draser · Post by **draser** » 23 Apr 2015, 11:49

Can you please post a picture of what is removed?

jaru · Post by **jaru** » 23 Apr 2015, 21:50

Last week I was only able to start the engine when the air intake cover was removed.
I could clearly see the throttle flap moving when the engine tried to stay alive.

: Air Intake cover removed; Intake cover removed.jpg (163.93 KiB) Viewed 1215 times

Today I installed the air intake cover again and to my surprise I was able to start the car with all 6 plugs and the air intake installed. It was running idle at 500 rpm, but when I tried to give it gas it would slowly (delayed) ramp up to 700 rpm and the die. However, I was always successful in restarting it.

: inside the car; Inside.jpg (74.59 KiB) Viewed 1215 times

I tired to post videos, but evidently the .mov extension is not accepted.
Thanks very much for your help draser!

jaru · Post by **jaru** » 23 Apr 2015, 21:54

I forgot one thing, the hazard light and the ABS light never went off, but I did not get any trouble codes. Could a bad ABS module cause such a behavior?

draser · Post by **draser** » 24 Apr 2015, 13:29

With part of intake removed was MAF out of air circuit? Was engine running in your picture, where I see MAF off?

jaru · Post by **jaru** » 24 Apr 2015, 19:24

Yes, the engine was running in the picture. After re-installing intake and connecting to MAF the engine was running the same way. I didn't notice any difference. I also put a new MAF sensor in and still didn't see any difference.

MyS40T4 · Post by **MyS40T4** » 25 Apr 2015, 18:45

Hello,

A fascinating problem!

But what a PIA!

Just to clarify, if you leave all spark plugs in and have one coil removed/disconnected, will it start?

A long shot, but there are some ground leads in the coil wiring that will lead to a bad misfire if not connected. They're near Coils 2 & 5 and held with separate M6 bolts to the head.

It almost sounds like there's something being grounded that shouldn't when all coils are connected...

Are all the coil wires in good condition? No possibility of a short? I'd disconnect all the coil wiring, pull it away from the head and check it for damage/breaks in the wiring.

My other line of thought - does anyone know if an S80 will run with the ABS module or sensors disconnected?

I'm tempted to think the original ABS error might be related. Is it possible that the car systems shutdown to the point it won't start (ABS error and can in limp home mode)

Finally, what was the last work done on the car before all this started? I've been caught by doing something seemingly unrelated that's caused an issue...

Good Luck!

jaru · Post by **jaru** » 25 Apr 2015, 19:43

Thanks for your thoughts! The original problem evidently started with ABS lights coming on and then engine not going above 1500 rpm or so. Later on it simply died and could not be restarted.

I found a bad ignition coil, which I replaced. I also checked the grounding points and the voltage to the coils, which were 14VDC on every coil. I also had spark on all 6 plugs, but car would still not start except when I physically removed one plug.
I did a compression test, which was ok, did a fuel pressure test, also ok. I removed all fuel injectors and activated each one and sprayed fluid through them and they seemed to work good as well. I checked the fuel pump by removing the fuel filter and run the pump. It seems to me that the pump is ok as well. I replaced the fuel filter, since I already had removed old one for the pump test.
The last time I worked on it I started to install all the plugs and it fired up. Then installed the air intake and it started, too. Finally I connected the MAF as well and it kept running.
Now everything is back the way it should be and I was still able to start it. However, it idles at approx. 500 rpm and when I give it gas it has a delayed reaction and once it reaches 700 rpm it dies. I'm not aware of changing anything that it all of sudden started up with everything installed. I do not get any trouble codes, but the hazard light and the ABS light stays on.

2000 Volvos S80 misfire

Re: 2000 Volvos S80 misfire