My 98 s70 runs and drives fine, but when I turn it off it doesn't want to start or starts but hesitates and then dies out. Ive recently replaced the head gasket and all other gaskets/o-rings that come with the kit.

While I was replacing this, I had took the metal cover off the exhaust manifold, and the foil tube that leads to the air filter box. Replaced the hole in the box with a sock (I know, but it works) and now my car leaks oil on top of my cam cover under the plastic valve cover. It leaks onto the exhaust manifold (now exposed) and burns making it smoke under the hood every now and then. I also noticed oil in one of my piston chambers from all the resting oil on top I suppose (don't think it would get past threads, I may be wrong).

Here recently it's been running fine after I replaced the head gasket. Minus some steering problems not related to engine issues. I have recently made an 9 hour trip and my car handled it fine. But few weeks go by and my car acts funky. It will start in the mornings, cold or warm. But after I drive it somewhere and turn it off, when I go to try and start it, it'll drive about 20-30 feet and then die. It's hard to start after that. Sometimes it will start and then die quickly. I'll also rev it sometimes and it'll go to about 3000 and then lose power and die. But this all happens and when it actually starts and runs, it'll go all day as long as I don't turn it off. New air filter, fuel filter, fairly new spark plugs and wires, distributor and rotor. I've had a bad MAF Sensor, I think for awhile now. When it's having problems, if the maf sensor is plugged in, it'll just die. When it's not plugged in, the car will lose power and try to die but didn't. Now it's hard to start at all. It'll run for a second and die.

What do y'all think? I've read alot of different forums and I'm trying to track it down.

 

How's the fuel pressure?

 

Check to see if the cam seals is letting moisture under the distributor cap. Sounds silly but I have seen it. And it's an easy fix. I worked on a 98 s70 about a week ago that ran fine until it got hot, we had just been there to do his pcv. After some looking I took off the distributor cap and the bad cam seal had let oil moisture past. If it has fuel pressure I'd guess that or coil problems.

 

Check to see if the cam seals is letting moisture under the distributor cap. Sounds silly but I have seen it. And it's an easy fix. I worked on a 98 s70 about a week ago that ran fine until it got hot, we had just been there to do his pcv. After some looking I took off the distributor cap and the bad cam seal had let oil moisture past. If it has fuel pressure I'd guess that or coil problems.

 

So update, it started this morning, very cold. Died a little after I started it. But a couple trys and it ran fine. But, when I tried to leave work, it didn't start. Tried to then just died, and wouldn't turn over afterwards. I checked the pressure on the fuel rail, but nothing. I'm thinking it's the fuel pump since the filter is new.

 

try jumpering the fuel pump relay as well if you get stuck. If that gets you going great - but typically the relays fail when the pump starts drawing too much current so its just an early warning to replace the pump. If you indeed do need to replace the pump, its a good idea to also replace the relay.

 

Thanks everyone, I appreciate the help and info. So today I was messing with it, and it still didn't want to start. So I unplugged the fuel controller relay and plugged it in and it fired right up, and stayed running. But when I killed it, it started having the same problems. Check the fuel rail valve and a stream of gas came out while the key was turned and kept coming out. But then i turned it off and on again and no fuel. Unplugged the relay multiple times and same problem. Starts but then stalls out. I'm thinking maybe just replace both of them. I can't tell wether it's the relay or the pump. Relay clicks every time, but fuel pump doesn't work everytime. Kinda some fishy business goin on here.

 

Ok, first thing is first. I would do a stage 1 tune up (new plugs, wires, Distributor cap and rotor, air filter, fuel filter, oil and filter change) Sounds like you have done some of that already so you are at least halfway there. Next, fix the known MAF issue. What type of plugs do you have in it? Volvos are known to be finicky about the plugs they like, I have found Volvo OEM or NGK to be the ones that work the best. Do you have a check engine light on, and if so do you have a way to read the code, as that it a good starting point. Also, oil under the plastic cover and on the head, and in the spark plug holes is caused by a bad oil cap gasket. Clean up the oil, get a new gasket and make sure your cap seals tight and that should easily solve that problem

Now this may seem funny, but the problem could be caused by the coolant temperature sensor. What does the temperature gauge say when you first try to start it cold? If it reads anything other than stone cold a bad coolant temperature sensor could be the issue. The sensor is located right below the thermostat in the thermostat housing, and it sends a temperature signal to the cars computer to tell it how much fuel to add based on coolant temperature. When the engine is warm, only a little fuel is required, but when cold, more is needed to keep the engine running. If the senor is bad, and thinks the engine is warm all the time, it will call for only a small amount of fuel to be delivered to the engine when more is needed if the engine is cold. This would cause a hard/no start, yet finally let the engine run when it gets a little warm.

Try all this and report back. Other possible causes are weak/bad coil, fuel pump, fuel pump relay.

Lastly, one easy way to see if the problem is fuel or spark related is this. If/when the car will not start, get a can of spray starting fluid. Spray a 2 second burst into the throttle body (into the air tube will work also) and try to start the car. If it starts, and then dies, you have a fuel delivery issue. IF it doesn't start, the problem is spark related.

Good luck, we will get this sorted out for you.

 

relays are fairly simple devices - they have an energizer circuit (usually the small spades) that actuates a solenoid which closes a contact switch to connect the two large spades. Relays can fail because the solenoid dies (no clicky ) or the contact switch gets pitted/corroded. If you can pop the cover off you may be able to rescue the relay by using some emory cloth to clean up the switch contact points. That said, its easier to simply replace then move on to diagnosing the pump.

 

Thank you everyone who helped. I found the issue. Fuel pump, go figure. Acts fine now. Does however start and drop rpm's to about 750-850 then back to normal 950. And when make stops it also drops to 850 then quickly comes back to 950. Check engine light is still on. I replaced maf sensor and also air and fuel filter. I also can't get the service light to go off with holding the button on the instrument cluster.

 

You need a tool to clear the service light on these models. Look on E-bay and you can find them for about $40. Read the code for the check engine light with a scan tool, it should tell you what is causing the issue.