Greetings,

2004 V70 n/a with 142k up to date with all routine maintenance. This is now the fourth time that this problem has occurred in the last year. No obvious environmental/driving behavior connections, and each time, the problem magically fixes itself with no explanation.

Symptoms: Upon turning the key, the engine starts, the RPMs reach 1500 ~ 2000 (the normal start-up 'vroom') and then dies. If I turn the key again, the starter cranks, but the engine won't fire. If I wait for a few minutes and then try again, the symptoms will repeat.

The car was running normally the last time I drove it. There has been no CEL or codes to shed any light on the cause. Some time in the indeterminate future, I will turn the key and the car will start as if nothing had ever been wrong. The last time this happened, I took it straight to the Volvo dealership when it started again. They played with it for a week but it always started, so they couldn't tell me anything.

I don't think it's a sticking throttle plate; when I give it a little extra gas pedal during the brief moment that it is running, I can make the RPM's spike higher (throttle plate opening) but the engine still dies in the same amount of time. Clearly there's spark, because it will start, albeit briefly. I feel this has to be a fuel issue.

From what I understand of how the fuel system in this vehicle works, there's really only three things that could cause these symptoms. Either I have a faulty fuel pump module, a faulty fuel pressure sensor, or something faulty in the throttle body/air meter system that is feeding incorrect data to the first two parts.

Has anyone experienced similar problems? Any thoughts on which part to focus on the most, and especially how to go about diagnosing which so I don't have to replace everything (pricey). Any help is greatly appreciated.

 

As I predicted, the car has magically started working again.

 

I had the same problem with my '04 V-70. Two weeks ago, It wouldn't stay started, the motor would catch and run for about one second then die. Over and over. After about seven attempts, I got it to run and I drove it around. Once I shut it down, it wouldn't restart. The next day, it started fine. I dropped it at a Volvo/Saab mechanic near where I work. He said he couldn't get it to not start, and there were no codes stored that would indicate a problem. He said that it may be the antenna that surrounds the ignition switch that reads the RFID on the key. I had him replace that ($150) and I drove around happy for about a week, then two days ago it started to do the same thing all over -- start and then die after about one second.
I've been combing the internet looking for some kind of answer that made sense. One thread suggested it may be the 'immobiliser' which you can reset by locking and unlocking the door 5 times with the key remote. -- tried that to no avail.
Another suggestion was the fuel pump relay. I had a heck of a time locating the dang thing, but I finally found it and it is certainly the cause of my problem.
The relay is nested behind the dash, tucked up behind where you would never expect, sort of in front of your left knee when you're seated at the wheel. It is NOT behind the fuse/relay access panel that's visible when you open the drivers door. It is NOT in the cluster of fuses and relays under the hood near the positive battery connection, nor is it in the cargo area next to the tailgate. To get to this little bugger, you have to crawl down under the pedals and undo the two Torx screws in the panel where the footwell light is. Then you have to pry that panel down (it's nested in there really good and held with a couple of clips that you have to pop out). The relay panel is light grey and faces the rear of the vehicle, but there is some room to get your hand between the panel and the dash. Luckily, this relay is in the bottom row on the panel. Mine only had two relays in the four sockets in that bottom row, so I picked the one that looked like it was in the right place (based on this diagram: http://ww2.justanswer.com/uploads/Sp...174657_fpr.gif )
The relay is black and about the size of two sugar-cubes. I removed the relay and stuck a paper-clip into the #3 and #5 sockets, closing that circuit. The car started! I removed the paper clip, and the same problem happened (engine started then dies after one second). Problem solved! (for me anyhow). The old relay now functions again, probably from being bumped around a bit but I'm going to hunt down a new one ASAP. I hope this helps. If you want to use the paper-clip trick, there is a misleading diagram on the side of the relay that shows a coil and the normally open, normally closed poles and the common. It's a typical DPDT relay, and what you want to do is short the common (#3) pole with the normally closed (#5) pole. Problem with the diagram is that it doesn't match the configuration of the spade connections on the bottom of the relay. It's the two fat ones that are all by themselves. They are numbered in the plastic on the bottom of the relay.
Good luck! This was such a frustrating mystery for me until I found that stinking relay. It is really deep in the weeds!

 

Thanks for the reply. My repair manual had made no mention of that relay, and they sure don't make it easy to get at. I'll get my mitts on one to be ready for the next time it cuts out. Hopefully this will be the end of the problem....

 

Can you confirm if you pulled the second relay from the left in that group of four? The numbers in the chart are a little tough to read. Also, if you have bought a new one, do you happen to have the part number? Thanks for all the help.

 

Just call the dealer or some other parts source and purchase a replacement. Volvo's have had issues with old fuel pump relays for 30 years.

After a while, usually 10 years, some of the solider joints crack and cause the electrical connection to break. Thus causing the fuel pump not to operate. I have a theory that this relay syndrome causes fuel pumps to fail from it's intermittent electrical impulses. Cutting it on and off to many times causing it to fail.

Anyway, on some of the older cars, the 850, some of the guys pull the relay, open it up, heat the joints, and put it back together. I doubt they ever have the problem again. Not many will have the car another 15 years for the process to repeat.

If you pull and push on the relay you will likely cause the joints to make a connection and work for a little while.

On a side note, it has been discovered by some that HP had failing solder joints on a few of it's laptop mother boards. Someone learned that the board could be removed from the computer, stripped of all of it's parts & tapes that can melt, put in the oven at 350 for 3 minutes to heat the solder enough to melt and then rapidly cool it so nothing got damaged from the heat. Fixed the computer for me. Maybe you can bake the relay and get the same result.

 

Bertelsen--
The diagram I sent seemed to be the one that matched my car, however, I don't have relays in every socket. There is a group of sockets to the right at the bottom. I don't have front fog lights, so there is nothing in #11 and whatever suspension option is controlled by #13, I don't have, so I pulled #12. The trick is to short it out with a paper clip or a jump wire, which does the work of the closed relay. Five conductors come out of the bottom of the relay. There's a group of three and a larger pair oriented 90 deg from them. You want to place your jumper wire across the sockets previously occupied by the larger pair at the bottom. This will close the relay. Start the car. Does it run? Good. Pull the jumper out. Start the car. Does it immediately die? If so, then it's the relay.
I went to Advance Auto and found a girl behind the counter who was clever enough to look at the relay and find a generic one that was pretty much the same as the Volvo one I handed her (regular relay from some other part of the car like the headlights or turn signal). It fit the socket, and functions just like it is supposed to.