1995, 850, No Start

Rbaratt · Post by **Rbaratt** » 15 Apr 2014, 22:29

I'm wondering if anyone has experience a similar situation. The problem has been intermittent over the last couple of years and it has been almost a year since the last event. So what happens is when I go to start my 1995 850 it will stumble on the initial start, stall and then just turns over without starting. I always thought it was a fuel problem (check valve) and have always managed to get it started. After the initial stall, I can try to crank it over and it sounds like it is turning over without any spark plugs and makes no attempt to fire. To get it to start, I have to get a boost from another vehicle and crank over the 850 while I holding the throttle to the floor. While I try to kill my starter, the motor eventually will start to sputter, catch, run rough while holding the pedal to the floor. The rough running eventually clears and I am able to let up on the throttle. Then it's back to normal running until the next event, which can be a while before it happens again.

This morning it happened and I was late for work and didn't have time to hook up booster cables. I did press the Schrader valve on the fuel rail and was quite surprised to see fuel spurt out. I tried to crank and just as it seemed like it might catch my battery was draining. So I took the S70 and will have to check this out later in the week.

I am fairly confident that I can get it start using my usual method but I would like find the root cause for this problem. I know there are some basic things to check but was just curious if anyone has had a similar experience.

Post by **misha** » 16 Apr 2014, 13:53

Rbaratt wrote:...To get it to start, I have to get a boost from another vehicle and crank over the 850 while I holding the throttle to the floor. While I try to kill my starter, the motor eventually will start to sputter, catch, run rough while holding the pedal to the floor. The rough running eventually clears and I am able to let up on the throttle. Then it's back to normal running until the next event, which can be a while before it happens again...

Could be everything from injection to ignition failure.That said...from leaky injector(s),bad FPR,bad Maf to bad cap & rotor,spark plugs,cables.

Try to start the car with Maf disconnected.If it starts & run,then it's bad.

When you manage to get it run...does it run normally or unstable,like rpm going up & down?

Remove cap & rotor and inspect them for wear and tear.

Is the check engine light on?

Rbaratt · Post by **Rbaratt** » 17 Apr 2014, 04:07

Misha, Thanks for the quick reply. I just watched one of Robert's videos on "lawnmower" syndrome and it seems to describe the issue that I am experiencing. Robert suggests adding oil to each cylinder to get back the lost compression. The first thing that I noticed was the change in sound when cranking, like it has no compression. I also found this explanation which describes how I have always been able to get the vehicle running.

"The true test of LMS is to do cylinder leakdown and see the air escapes into exhaust.
When the engine has LMS the cure is to crank engine over long enough that the exhaust valves get worked and freed and the tappets then relax when the valves now keep pressure on them as lobes lower valves back to seats. Fresh plugs will makes engine start more readily but if there is low compression then it will still take long cranking. This goes against normal practice but you must keep your foot on the floor while cranking and crank over for a minute to 90 seconds before giving starter a rest. If the engine has LMS then it has little compression and the starter load is very low and it will not overheat easily in that case. cranking a normal compression engine over that long would be bad for starter. "

I won't be able to work on this until this week-end, and I will report back with more information then. Thanks again.

ANTS · Post by **ANTS** » 17 Apr 2014, 05:04

hi im not sure if I am on the correct site - I have a volvo 850 glt 1996 - when cranked it does not start - but if a cap of fuel is poured down the intake ,it starts up but dies straight away -the fuel pump can be heard running . I even tried unplugging the maf sensor and it runs with or with out the sensor plugged in once fuel is fed manually through the intake - can some-one assist in guiding me in the correct direction

Rbaratt · Post by **Rbaratt** » 19 Apr 2014, 10:48

Definitely fits the description for lawn mower syndrome. I did my usual long cranking with the gas to the floor, and it started up. I read the explanations that attribute the loss of compression to fuel washing the down the cylinder walls, and I guess I just have to accept it and move on to the next issue.

-Rick

gdog · Post by **gdog** » 20 Apr 2014, 00:52

@ANTS: sounds you have a fuel pressure issue; ck the fuel rail with a gauge and go from there.

@ Rbaratt: LMS is a myth. Unfortunately it's being perpetuated on certain volvo sites. You have engine tune and/or mechanical issues. Have you ckd engine compression?

Post by **Ozark Lee** » 20 Apr 2014, 13:37

gdog wrote:LMS is a myth.

Thank God you showed up to let us know that.

...Lee

Post by **dosbricks** » 20 Apr 2014, 14:17

Even if there is nothing wrong with it, it's still is an electrical problem.

(sporadic nature).

Rbaratt · Post by **Rbaratt** » 23 Apr 2014, 04:39

Myth or not, the symptoms and solution to get the vehicle running are what is described under the LMS "myth". I have the vehicle back in the daily rotation and at the next service I will check the compression. I am not trying to perpetuate the myth of LMS but I found this theory for the cause of LMS on another site...

"The 4 valve/cylinder engines use small valves and the accompanying lighter valve springs. The exhaust valves will on any engine get some accumulation of deposits, primarily from fuel combustion with some portion from oil that seeps through guides for valve stem lubrication, that in some situations can cause the valve to slightly bind in guide. On a cold engine the guide-valve clearances are reduced due to temperature and the fact the metals of guide and cyl head shrink more than the metal of valve stem. You attempt to start engine and the oil system can and does build oil pressure on these engines in one crank revolution. This leads to the hydraulic valve lash adjusters ("lifters") filling and extending ("pumping up") while the sticky valve is closing sluggishly and not following the cam profile"

I have never had one of these cylinder heads apart, but I wonder how likely it is that the valve springs could be that much weaker to keep the valve from following the cam profile?

optowalt · Post by **optowalt** » 23 Apr 2014, 06:41

I had a similar prob with my s70. When I turned the key, the temp guage registered like it was warmed up already. I replaced the temp sensor and the prob was solved. It seems the ecu reads that the engine temp is up so it sends less gas to fire the engine up. Just a thought.