My daughter drove to mall, got call it wouldn't start. Towed it home. Spark not issue, but no pressure at fuel rail. Took out fuel pump relay and jumpered 30 to 87-2 according to book, didn't hear anything but will recheck. I assume ignition has to on? I've pulled down what I could find in past forums and will reviewing it for a plan of attack. I'm thinking fuel pump as possibility. Any thoughts?

Definitely Fuel pump. If it aint getting there then thats it. Heres what to do. OK have someone turn the car to the 2nd slot before starting the car. Like if one would start it but not go all the way. You should be underneath it near the back near the pump. Listen carefully for it to turn on. If not than its NG. Also try tapping it...my old Benz had a fuel pump problem and tapping it would do it.

At least yo dont have to drop the tank!

Just got back in from trying the tips from FAQ, the relay did click when turned on. I jumpered 30 and 87/2 and nothing happened, but then I believe I jiggled the ignition switch key and both pumps came on (ignition is a little flakey). It started. Might be a coincidence (flakey ignition), but definitely an intermittant issue.

Dear johns1,

Good a.m. and may this find you well. Another possibility is that the crank/RPM sensor has failed. This sensor's signal - it is located atop the transmission bell housing, just behind the engine, at the 10 o'clock position (as you face the engine) - keeps the fuel pumps running, after their initial, 1-2 second "spin up".

Heat and time eventually cause the RPM sensor's wiring harness to crack, allowing moisture to get in. When the sensor shorts, the signal is lost, and the fuel pump stops. Intermittent failures are common.

If your car has the original sensor, it is time to change it.

Your mention of a "flakey" ignition switch may exonerate the RPM sensor. Even so, a 13-year-old RPM sensor is on borrowed time.

Hope this helps.

Yours faithfully,

spook

Here, Here! (In case you didn't get it - old english for I agree)

I have 220,000 on my 940 and have replaced rpm sensor at least twice. As Spook say, it's cheap insurance ($35.00) to keep you from being stranded (as I have been). Held by 1 bolt and unplugs at firewall. About a 5 - 10 minute job. It looks difficult to get to, but is easy standing on driver's side and reaching across back of engine and down and slightly toward passenger side of bell housing with a 10mm (I think that's right) flat racheting wrench. You can basically feel for it easily, without even seeing it. Just don't over-tighten or the cast aluminum threads will strip.

If you have not changed fuel pump relay or radio suppression relay, then the same would apply ($25.00 each).

Johns1 says "spark is no issue". How often will a bad RPM sensor provide a good spark? Also, "no fuel pressure at rail" and no pump noise when turning the key. How about the fuses? Even if the relay clicks, I'm not so sure that a blown fuse wouldn't interupt the high-current side of the relay, even thow the low current side is producing a click. A quick and sure-fire (no pun intended) way to verify the ENTIRE fuel pump electrical system in one fell swoop is to break into the power wire where it connects to the pump and measure for the 1 or 2 second 12v pulse when you turn the key on. If it's a non turbo 940 in the U.S., then it's probably a single pump Regina. There should be a wire disconnect near the L/H trunk hinge. The heavy pink wire is the pump power wire. If it's a two pump system with the high pressure pump located under the driver, then you need to check the power to both pumps. If you have electrical power to the pump(s) but no pump noise and no fuel pressure, then I guess you've found the problem. I just went through this with the wife's 740 Regina (single pump). I picked up a pump at Advance Auto for around $60 plus a $6 pick-up screen. It was a perfect fit although in my application I had to solder the wires.

Good luck.

pump wire right were Chris said, tapped in to in and signal was there but no pumping...getting new fuel pump.
thanks
js

Good job.

I went through a pump R&R about a month ago. We ran the car seriously low on fuel one day and then about a week later the pump failed - not sure if there was a connection there or not, but I guess it is certainly possible. I'll never runit that low on fuel again.

Thanks for the suggestions. It's a non turbo and has 160,000 miles on it. I think I will take out the insurance on the RPM sensor and pump relay. To be more clear there is spark, but I didn't quantify if sufficient.

It is a 2 pump system I believe from the noise (haven't crawled under yet) and I will check each directly as that will allow me to differentiate between what the intermittant problem might be. If the signal is there and it goes on, then ok. I'm going on line for parts so won't have all answers til weekend. Local dealer wanted $60 for the relay, so I'll wait few days. I'll check the pumps tonight.

js

From FP Groton or Swedish Engineering, that relay is about $25.00 and an RPM sensor is about $35.00.

Gary