Howdy, I hope yall can help me out with this 1997 850R I cant seem to get started. I bought it not running with a broken fuel line but that has since been repaired and it still wont start. It does turns over just doesnt start. The previous owner told me that the car was running fine but just wouldnt start one day. He told me he was able to get it to start with starting fluid and he broke the fuel line when trying to pull the fuel pump. The fuel pump was shooting out fuel when the key was turned to the II position.

At the moment:

-There is pressure in the fuel rail (I have tested by the schrader valve)
-There does not seem to be any spark (I pulled out a plug and had someone crank the engine)
-There does not seem to be any fuel on the spark plugs and cranking the engine.


My guess is its either the camshaft sensor or a bad ecu as there is no spark and no fuel in the cylinders. The guy I bought it from thought it was the fuel injection relay but I tested it with a multimeter and there was voltage coming from the wires when the engine was on. (I think thats how you test it).

Any help is greatly appreciated.

 

Listen for the fuel pump to "hummmmm" for a few seconds when you turn the key to "on" but not cranking the starter. If you hear it humm for a couple of seconds then shut off, your fuel pump relay should be ok. I would still consider either replacing it or having one on hand as a spare. Try that first. If still no start, then it could be a crank or Cam position sensor. Is the check engine light on? If so, read the code set and that should help point the way to the issue.

Good luck

 

My guess would be a bad cam sensor. It's under the upper torque mount on the back of the exhaust cam. It can be replaced in less than 10 minutes if the screws don't strip out on you.

Usually a car that has sat an extended period of time would have had a dead battery killing your chances to pull codes.

 

Check fuses too. My fuse #2, "central locking/anti theft" fuse was blown when mine wouldn't start. If this fuse is blown, it cuts spark and power to the injectors.

The reason my fuse blew was because I had swapped ECUs without going through the proper procedure before starting. When you swap, or sometimes remove and re install and ECU, it will flag the security system. When this security system is "flagged" it will blow this fuse when you try and start the car. To avoid blowing the fuse, after an ECU swap, you have to lock the driver door twice (with key), then unlock door twice (with key).

In the case that your fuse is blown. Replace the fuse. make sure everything is shut and nothing is on.. Lock the car twice, unlock twice, and try starting. One can only hope it's that easy.

Otherwise I'd try a cam sensor next.

 

my R had a starting problem for over 2 years, every time it took more than 3 minutes to crank, but eventiually it started every single time. ive replaced the camshaft sensor, it got better but still was there, crankshaft sensor, nothing changed. eventiually it stopped completely, and then we found out the ground wire to the ecu was oxidized. after we fixed it it started again only with the same problem of taking so damn long to actiually start. it also seemed as if it had a very high compression and the starter engine had to work very hard. after the starter engine broke completely and i replaced it. it worked perfectly again, the starter engine couldnt deliver enough power, so it took more amps and didnt leave any amps for the spark plugs. so it cranked very heavily and wouldnt start.

 

If you ever need to replace the battery consider getting the bigger battery that fits the holder. The standard one is a "Group Size 47". The higher capacity battery is a "Group Size 48" with more reserve and cold cranking amps. It's cheap insurance and a must in colder climates, added stereo equipment or just reliability. It bolts right in. In fact at Autozone the bigger better battery is actually 5 bucks cheaper and 110 CCA more power with the same warranty. On a sub-zero morning you can hear the difference in the cranking speed.

Search: 48dl | Battery | AutoZone.com

List: Battery - Automotive - 1995 Volvo 850 | O'Reilly Auto Parts

Doesn't matter if it's fleetfarm, sears or ..... it's still a 48.

This is a picture of the "48" in my car. You can't really tell the difference unless you put a 47 side by side.

 

Thanks for the responses everyone.

All the fuses look good and the contacts for the ECU are pretty clean. I gave them a quick cleaning anyways with sandpaper and alcohol.

I went ahead and ordered a new camshaft sensor which should be in wednesday. I pulled the old one and tried to clean the contacts. I will have to try to jump it again in the morning and see if that was the issue.

There was a stored code of P0120 for TPS but I'm not sure that would stop the car from starting or would it?

How do you check the ECU ground wire for corrosion? Where is that located?

 

it was a while back so i dont remember exactly. but how i found out was getting a pinout diagram of the ecu, and simply checking every wire that could be it if it still connects using my multimeter. the only wire that didnt make contact anymore was the ground for the ecu, so i repaired it and it worked again

 

So I went ahead and replaced the cam position sensor with a new unit and cleaned the ecu contacts. Then I did the lock twice unlock twice and tried to start it when jumped and it still wont start. There are no blown fuses either.

Now the fuel pump does not appear to be priming so I tried jumping the the pins 15 and 87 to see if I had a bad fuel pump relay and still nothing.

I cant seem to figure this out. The only thing I can think of is that the fuel injection relay may be miswired. Does any one have the wiring diagram for the fuel injection relay? or any other ideas?

 

No fuel pressure, no sound of the fuel pump running when you turn the key, no fuel pump sound when you jumper the relay. Try running 12v directly from the battery to the fuel pump. If still nothing then it sounds like the fuel pump is gone.......

 

I'll have to test the pump however it was literally just working. There was pressure in the fuel rail. I think this has to be something electrical as their is no spark or fuel but it will crank all day. There is a flashing arrow on the dash, I read somewhere that could immobilize the car, is that possible?

 

When a fuel pump goes, it usually just stops working......no long slow death, just works one minute, and not the next. If the pump does work when you wire 12V directly to it, it could be the relay, or a blocked line somewhere

 

Sorry; can't agree with that. As the pump wears toward its ultimate demise, the motor bearings, brushes, etc. are getting sloppier and closer to death. Under these conditions the motor can (and often does) stall when called upon to work. It's at these critical times that rapping on top of the pump housing often will resurrect the pump for brief time, until it stalls again. If it does start working again after being jostled, that's a tell-tale sign that the pump needs to be renewed asap.

Experienced this first hand and seen it on too many other posts too.

 

Maybe you got a bad cam sensor. Try one from a wrecked car in the junk yard. Could be a crank sensor as well. Not to many things that cut spark and fuel at the same time. I really doubt that anyone would rewire a fuel pump relay.

 

I am a sucker for diagnosis. For your no-spark, try this:
http://www.volvoclub.org.uk/tech/ser...sicTesting.pdf

It worked for me. I know it's too late to avoid random part swapping, but clear thinking is still free anytime.

You can worry about the fuel pressure later. That is a much simpler system to diagnose.

 

Sorry as well that I cannot agree with you. I have had two (yes two) fuel pumps work just fine when the car was shut off. A few hours later when I went to start them, they were dead, either due to an internal power problem, or a mechanical......so it can and does happen.

 

Ok, lets get back to basics for a second. I know of one sure fire way to determine if your problem is fuel related or not. First, take off the air intake hose from the air cleaner box. Next, get some starting fluid and spray a couple of shots into the hose (toward the throttle body one the engine. Try to start it. If it tries to start, or runs for a couple of seconds then dies, that will determine that you have spark, but most likely poor/no fuel delivery

 

What he (Psaboic) said. +1


I like the basics because some times when you don't have something it's because YOU forgot something. In this case it was no spark

 

Okay so I finally got this thing to start up and was able to drive it around a bit and even got it on the freeway. It was running okay for a bit but would hit about 4000rpm and just cut. It was like the revs wouldnt go past 4000rpm no matter what. I parked it then took it back out 15 minutes later and the car was just running very very rough. So I luckily saw it failing and pulled out and it just quit. I had to get it towed back to kamy house but I think the problem is the MAF wire. We tried jiggling it when cranking it and it was like the engine wanted to start a few times but wouldnt catch completely. It looks like the previous owner had a zip tie on it so the wires are probably bad. I thought that if you disconnect the MAF it should still work. Anyone know if the car should fire up with a disconnected MAF?

 

yes it should fire up even with the MAF disconnected