Hello again Lads,

I went out to run a quick errand today and when I started home, the engine stalled right after I put it in drive. After repeated long cranks, it finally stubbornly started. The engine ran/revved normally until I put it in gear, then it stalled again after moving a few feet.

It was almost starting, but sputtered and quit. The engine seemed to almost catch and start just as I turned the key off. Weird.

Anyhow, again, after numerous lengthy "almost starts," I got her going. I revved the engine for a minute or so (to get a little juice back in the battery), put it in drive at around 1500 rpm and drove home. Every thing was normal since the non-start event. Idled perfectly in my driveway for 20 minutes.

I have noticed an occasional rough idle recently, and I've had to rock the gear shift a few times because the PNP switch is getting balky I guess.

I opened the hood and just stared. Don't know what to investigate or look at.

I know there have been many discussions regarding rough starts, but I guess I never bothered to read them.

Anybody suggest a course of action? (I'm thinking fuel filter...)

Thanks!

- thumbs

A real quick visit again to lawnmower syndrome - It was posted several times years ago

Our experience with it was within a few weeks of getting our first 855. I had it towed to a dealer and fixed. I had moved the car a few feet to stay in the shade during its first wax job.

Three 850s and over 250K miles with four drivers and it never happened again.

BECAUSE - our family rule was - Never start an 850 without bringing it uo to operating temperature.

I always had a spare set of plugs in each car.

FYI:

I used to have exactly the same symptoms on my '96 last summer.

Finally, I replaced the cam position sensor and the ignition coil, both at the same time. It's one or the other most of the time. I preferred to replace both at the same time since you'll have to remove the air filter box anyway to have access to the parts. The car has been perfect ever since.

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Norm

I cannot help you on the first stall, but after that, your problem was what is called - lawn mower syndrome - trouble starting the 850 engine after it ran for a short time.

Named for moving your car to get the mower out, then the car won't start again.

If you have the car towed to a dealer, they will start the car, change the oil and filter and put new spark plugs in. This is because there is an extra fuel condition when the car is hard to start, and this can foul the plugs and thin the oil.

If you observe carefully, the motor will actually turn over a little bit faster during this condition and try to start.

There are several theories as to the cause of lawn mower syndrome - most relate on how the valves stick open, causing a lack of compression.

My take on the situation is that the first thing to get warm when the engine starts are the valves. This causes them to stick in their guides, causing the lack of compression.

Thanks for relaying your info regarding the "lawn mower syndrome." It sounds like a valid theory, but the 850 has been running perfectly for the past week. There have been dozens of engine starts in the meantime with no hard start events at all.

And I have probably only have around 10,000 miles on a new set of plugs. I cleaned the MAF sensor a couple months ago. (Wasn't dirty...)

I'm due for an oil change pretty soon, so the oil change and filter issue will be taken care of.

My hard start event was after normal city driving for maybe 30 minutes or so. Then the hard start occurred after maybe 15 minutes with the engine off.

- thumbs

My 93 had the same issue as you have described. Had a code stored for Cam position sensor signal missing and one for coolant temperature sensor signal intermittent. No check engine light came on. Changed both and now no problems for the last year. The new CPS part is upgraded from original according to parts guy. He said most original cps parts fail on the 93 before they turn twenty years old.

Thanks for your reply and advice.

I gotta read up on the Cam Position Sensor. Would the bad CPS cause intermittent engine start problems? Or does it go bad and "stay bad?"

Thanks for the responses gentlemen. I going to pull the codes to see what's going on.

The 850 has been running flawlessly since that hard start event, by the way.

- thumbs

All the usuall suspects, but always check your codes or have them checked first. Most of the time your car will tell you what's wrong. Sounds like CPS or MAF or just a tune up is needed. My last hard start ordeal was caused by a bad coil.

If you have never replace the fuel pressure regulator check this first.

The regulator is located in the fuel rail in line with fuel injectors.

How about normal items like plugs, cap, rotor, clean throttle body, have done this items lately??

I haven't done a complete tune up because the 850 has been running so well. It's been a while since I cleaned the throttle body, and the wires and distributor are getting on in years.

Is there any way to test the fuel pressure regulator? Can it fail intermittently? Or does it go bad and stay bad?

Thanks for your concern.

- thumbs

The fuel pressure regulator is hiding on the passenger side of the fuel injector rail. It has a vacuum line that is routed to the tree at the throttle body, check that vacuum line for gasoline - it should be dry.

There is also the possibility that there are other vacuum leaks, which will make the engine run rich and foul the spark plugs.
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Keeping it running is better than buying new