Hi there,

I'm new to the forum so I'm sorry of something similar has been asked before but I have been searching for hours.

I have a 97 850 non turbo that I purchased a few months ago. Every now and then between 5 to 10 mins into a trip the car will start to splutter and stall. It normally happens when pulling away from a set of lights, presumably because this is the when the load on the engine is at its highest.

Now the first time this happened the car had not been used for a week and it was in torrential rain, it happened again recently and was after a night of bad rain and again the car had been still for a 5 days or so.

When it first happened the car stalled and was a right pain to get started. It seemed to backfire every few attempts and would fire twice and cut out on others. I can feel its going to happen now so I drop the clutch and let it idle its way out of it now.

I have already replaced the spark plugs for new oem bosh plugs. When doing the plugs I found one of them was loose compared to the others. Now all 5 are done up to the correct torque. I am concourse this could have made some of the injectors dirty

The exhaust pipe is very sooty suggesting to me it's running rich or has been running rich.

I am planning to do the following maintenance to it but I was wondering if anyone has any suggestions of other things to do or the best order to try and hit this issue on the head. I don't want to spend loads on new parts if its a scrap job:

Oil change
Oil filter
Air filter
Fuel filter
New HT leads
New distro cap
New coil pack

I was going to pull the codes to check if the following need changing
MAF sensor
O2 sensor
Temp sensor

One last thing that's worth adding was I used the car every day for 10 days when we had lots of snow and ice, air temp never got above 0c, and it ran just fine. It didn't have a single one of these "moods" I described above.

There are also no fault lights on at all. I occasionally get an ABS light, I'm talking once a month, so I'm guessing a sensor is on its way out with that one.

I know it's a long story but its got me and my friends split on the best order to replace things in in order to fix it.

Thanks in advance.

Alex

 

check for fuel pressure first and get back to us. it looks like you are having fuel delivery problem. do you have any idea on when the fuel filter was changed?l clogged fuel filter could cause this kind of problem too. here is a link on how to check for fuel pressure. pressure should be 39-42 on a warm engine. if you check for pressure and its good, then you can check if your MAF is good. is the check engine light on?

 

Running rich means not enough air... When was the last time your PCV system was replaced?

How old are your wires? They have a date stamp on them.

Chances are, you have a fuel pump relay going bad, or your pump is going bad. Could have a few issues. Start with vacuum, PCV. Then move to checking compression. All of the items you listed above are maintenance items, not moods. An oil change? Not sure why you listed that, oil should be changed all the time and should never cause drivability issues unless your out of oil.

 

Thanks for the quick reply's.

I will check the maintenance history tonight and try to find out when some of these items where done.

I listed the service items for completions sake.

I think my the phrase "moods" was confusing. the point I was trying to make was that the car ran fine when i used it every day in the cold weather. it didn't loose power or stutter once. I call the stuttering a mood because after 5 - 10 min after it started spluttering the car runs absolutely fine.

 

do whats RSPI listed and get back to us

 

I always want new plug wires in that situation (misfire under load, worse in the rain).

 

Did it act like a misfire or like the car was running out of gas? Or like it was flooding?

Where's your coolant temp gauge? Should be right abut 3 o'clock position and get there w/in a few minutes. If not, you need a thermostat. If it was sitting below 3 PM, that will make it run rich, which may be fine when it's friggin cold out but run crappy otherwise. Were the old plugs black?

BTW: most of that other stuff you mentioned is regular maintenance so do it anyway..

 

I thought I would provide a quick update for those who are interested.

I took the advice on here and had a look at the pcv system...... Completely clogged up. I have now stripped out the inlet manifold so I can replace it... Waiting for the parts now.

I also replaced the ht leads. The date stamps where 0311 and 0312. I took this to mean 2003 so replaced them.

I did the fule filter as I said I would. Looked like the original one judging by the Ammount of rust around it.

I'm now facing a new problem. The oil drain plug is well and truly stuck. I'm going to wait until I can get the engine running again and try when it's been warm. I know you should do an oil change after doing the pcv system. How many miles do you think I'm safe with?

 

what do you mean by how many miles you think you are safe with?

 

Once you do the PCV and make sure you dig out or push in the crap in the drain holes the PCV unit uses I'd run the engine up to temp, maybe take a short drive and then change oil and filter.

You might want to order or pickup a replacement drain plug and gasket before you start on yours in case you end up under there with a vice grip and hammer. Remember the pan is aluminum so be careful how you muscle it out.

 

Update:

I have now replaced the HT leads, the Fuel filter, air filter PCV system inc vacuum hoses and done the recommended oil change.

fired the car up on Thursday and after idling erratically for about 5 mins it ran like a dream. I figured that was the ECU re-training or air getting out the fuel lines, and this caused the erratic idling.

I drove the car fine on Saturday after the oil change and again it ran really well. No more nasty smell coming from the engine bay and the fuel economy seems better.

After some reading up on the temp sensor I timed how long it took to for the temperature gauge to get to 3'o clock. It takes about 20 mins and I think thats too long. I recon i probably have a thermostat stuck open or something like that?

I decided today I would use the car to get to work as the loss of power seemed to happen more when I was driving in heavy traffic and at the weekend I was on clear roads, albeit wet cold ones.

Today It was a real pain to get it started. cranked fine and after a few attempts started to fire every now and then and finally started. While driving to work I had a few moments when the car sounded like it was going to stall and I really had to rev the engine to get it moving.

I'm leaning towards and intermittent fault on the fuel pump relay at the moment... any more thoughts?

 

as stated get a new relay and see if that helps.

 

If you have a OBD-II meter, check the temp before you start it, after it warms up and a few other times. If you have a bad temp sensor it will make the car hard to start, run rich and other idle problems. So, you may want to check your temp readings and if they are bad, replace the sensor with the thermostat.