So I get back from x-mas trip and the next morning my wife tries to go to work in her 94 850 (non-turbo)with 170,000 miles on it. It does start and she take my commuter car instead (so I am driving my full size 79 chevy pickup which gets 8 to the gallon).
This is where I am at right now:
I have spark to all plugs and a good coil.
Fuel/air filters replaced.
I have fuel pressure (after turning the engine over, I press the schrader valve and gas spays out)
No trouble codes are thrown


What's the procedure for testing fuel pressure on this engine?
What else should I look for?

Jeff

 

Testing fuel pressure on this car is as easy as screwing the guage on the valve. It should be around 30 to 35.
Check for injector pulse. Remove one of the plugs and try to borrow a Noid light and plug it in. Then crank it over and see if the light flashes. If not then look at the Cam sensor and the Crank sensor.

 

So do I test the e-fuel pump like a mechanical one and crank the engine or is there an easy way to jumper it? (or I should just try turning the ignition to the on position?)


Would a faulty crank or cam sensor or a injector control module throw codes ?
thanks
jeff

 

Just turn the key on to see if you have fuel pressure.

The cam or crank sensor won't always throw codes. But sometimes will.

 

So I have bout 43 psi of fuel pressure and got the noid light to flash on a couple of the wires. The battery is getting weak so I got it on the charger right now. With another battery, it turns over fine and I turns over, but this time I hear a thud. IT could just be normal sounds of a engines compressing or it could be the engine barely firing (I am used to loud engines like my 79 v8 and am half deaf, so I am just not sure).

I am running short on ideas here [sm=headbang.gif]
So, what is left?
Clogged exhaust? I'll check that tomorrow.
Oil pressure switch? (how do I check that?)
Can timing belts slip, though it prolly would have had some sort signs that it was slipping.
This car ran fine before my wife didn't drive it for a week.

If I don't get this running by the end of the week, she is going to have it towed to the dealership. (not only will that cost an assload of money but my manhood will shrink! [sm=boohoo.gif])

Jeff

 

See if you can get a good flash from the noid light. It you do then it should run.

Here is something else to try. Get in and push the gas pedal all the way to the floor and hold it. Then insert key and crank like there is no tomorrow and see if it catches.

Some times the lifters will bleed down Making it hard to start. By the time they fill up the car is flooded.

When you hold the gas down and then turn the key on it shuts off the gas.

Only try with a full battery and after the car has sat for a little while.

 

I have a 94 850 with about 266,000 miles. If I make the mistake when starting the car by letting go of the the key too soon just as it starts, then I am in for it. Sometimes, when I do not use the car for a few days, I may have the not starting routine immediately.
It even happens when car is garaged

The engine cranks, but does not even try to catch. Solution- DO NOT TOUCH GAS PEDAL. Keep cranking for a straight 1 and a half minutes. Engine will try to catch-once every 2 seconds then closer and closer-don't help by giving gas or you lose-DO NOT TOUCH GAS. When it REALLY catches, gently give gas so revs 2000 + DON"T STOP. If you let off gas-it could drop the tach to zero.

My mechanic believes last resort beyond this is keep gas pedal down and keeping continuously cranking.

If this doesn't work-you may be flooded and need to tow. Then it is a lot of work to clean everything.

I have a s70 98 which did this once.198,000 miles

My 2002 s60 94,000 miles- seems no problem like this.

Thoughts?

 

I got a chance to work on the volvo again before work today. So I tried to start it as describe, with no affect. I pulled the wire to the coil and tried to start it. That "thud" was no longer present. So it is firing, but with not enough power behind it do anything.

I cleaned the battery cables again and put in a brand new battery... the old one would still crank the engine but couldn't hold a charge for very long.

The noid light flashes brightly one or two times at first, then dims as I continue to crank it on all 5 of em.

I pulled all the spark plugs and am going to let the cylinders "dry out" over night. The plugs were soaked in gas and have a lot of build up. The plugs were replaced last summer along with the rotor and cap. The plugs wires are newer. For all those who are wondering I very little improvemnt in performance with the bosch +4's... waste of $$. It did run smoother but that more likely because of the cap/rotor and a cleaned up MAF sensor.

Attached or some pics of one of the plugs. They all have similar build up and it flaking off. Is that normal?


Jeff


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It is running to rich. They should be a little lighter in color.

 

so if is running rich, then it is a seonsor problem.
Which MAF wires do what?
which O2 wires do what?
Does the coolent temp sensor contol the gauge as well as imput into the ECU?
What other sensors should I look at ?

jeff

 

I could also be a vaccum leak.
Coolant temp sensor controls the guage and sends signals to the ecm. Also a broken thermostat could make it run rich.
A bad O2 can make it run rich.

 

I just had to replace the battery and the Starter on my 94 850 turbo ... is there any chance at all that this could be a starter problem ? we didnt think it was either at first .

 

Thanks for all the input.. Got it to start and it ended up through a cam pos sensor code
Replaced it and it runs far better


jeff