98 S70 GLT Perfectly fine, now won't start/idle

Duake · Post by **Duake** » 20 May 2010, 08:54

Guys, I'm totally stumped on this one.

My car has been perfectly fine the past 18 months I've owned it, with only one major problem that was fixed in September last year and that was some seals that broke. Been running fine ever since.

Well, yesterday, I drove it around 12 p.m. to grab some lunch and came back home. 2 hours later I was going to go pick up my kids from school. Car started and then abruptly died. Tried it again and managed to get it running a little longer, but it was erratic and white smoke came from the exhaust. It eventually stayed on and seemed fine, so I started driving out of the complex. I get about 50 ft. from my parking spot and the car just dies while I'm driving it. Needless to say, I pushed it back and drove our Jeep to get them instead.

When I got back, I got in the car to check it out. Car started fine, like normal, and I was able to drive it with no problem around the complex. After I parked, I turned it off, waited a minute and started it again to see if it would. It had no issues, so I figured it was just a fluke or something.

This morning I had the same crap happen. Car would idle erratically and then just die. I just now messed with it again and it won't even start completely. Nothing is dripping. Fluid levels are perfectly fine. There is nothing I can think of that would cause such a dramatic change considering it was fine yesterday when I went to get food. I changed the spark plugs 2 months ago, but I think I would have experienced something bad from that before now.

Any ideas on what it could be and that I can possibly look into myself instead of going to a shop? Any help is definitely appreciated.

Oh, car only has 116, 8xx miles on it.

David

Post by **jblackburn** » 20 May 2010, 09:02

2 things come to mind to me:

1) MAF sensor has died. Unplug the electrical connector just after the airbox and try to start it.
2) Fuel pump relay is fluking out. This usually only happens when the car is already warm, though, but it can happen either way.

Duake · Post by **Duake** » 20 May 2010, 09:19

Unhooked the MAF, but same situation. Plugged it back in and tried for the hell of it. Nothing. Without the MAF though, the engine starts fine up to the point of going into idle and then dies. Plugged in, I can crank it and nothing will "catch" to start the engine. Holding the gas pedal down and starting it works, but won't stay on after I lift off the pedal. I had a similar random situation happen with an 89 Grand Prix where I had to hold the gas pedal down to start it and then keep revving it to stop it from stalling. The fuel filter was apparently the culprit there as told to me by the mechanic.

I'm starting to wonder if it could be the fuel filter on the S70 also. Any thoughts? And if it could be the fuel pump relay, what could I do to check that out?

Thanks!

Post by **jblackburn** » 20 May 2010, 11:02

It sounds like it could have gotten clogged up.

What I would do at this point is test the fuel pressure. There is a blue cap on the right (drivers) side of the fuel rail that you can take off and access the valve for testing. You'll want to see ~43 psi before the car starts, 38 with it running.

Duake · Post by **Duake** » 22 May 2010, 06:59

I don't have a pressure gauge to check the PSI. I was looking into the Fuel pump relay fix and thought that may be the issue. Could that be it possibly?

Post by **Pauloil** » 22 May 2010, 09:42

yes. read on this site how to jumper the 2 pins and bypass the relay.
figure out how to replace fuel filter, esp if it hasn't been done yet. the interval is 100K, but many replace fuel filter every 50K. the actual presssure number isn't essential, but when you turn key to pos II, should have a good pressure with gas coming out if you push on the schrader valve.

raint5 · Post by **raint5** » 22 May 2010, 12:50

had similar issues with an 850, you'll find your fuel pump relay under an access panel where your fuses are under your hood, remove that panel and pull relay #103 place a jumper wire between pin 15 and 87, sounds confusing, will become apparent when you pull the relay, you can use a wire or paper clip, just something that will conduct electricity, try starting the car, if nothing changes you may need a new fuel pump, thats what i had to do with mine,
good luck

raint5

Duake · Post by **Duake** » 31 May 2010, 07:52

Okay, I finally did the paperclip thing yesterday. I jammed it in the 15 and 87 slots and the same thing happened. After I stopped trying to start it and went to the engine, I could hear something running. Sounded like fuel flowing via air from the back of the engine. I pulled the paperclip, which was hot!, and the sound stopped. I put the relay back in and the sound came back but only for a second and then stopped.

The next thing I guess is to check the fuel pump. I'm already getting the parts to change the caps in the relay, so it won't hurt for me just to do that anyway. It only cost me $0.25 for the caps, so its no biggie.

Besides the fuel pump, could the fuel filter cause this also?

Duake · Post by **Duake** » 01 Jun 2010, 17:30

Okay, I just changed the caps in the relay, but it's like I didn't even do anything. Is it possible that bad gas could cause this? Like diesel? Nothing ever happened like this until the day after I got some gas. Since I can't run the engine for any length of time, what else could I look at to see if I can diagnose the problem?

Duake · Post by **Duake** » 15 Jun 2010, 09:50

Ordered a fuel filter a couple days ago. Should be here today sometime. I'm going to replace the filter and hope that will fix this stupid issue I'm having. I read the thread on replacing it, but since I can't run the engine at all, would the pressure be relieved already? Should I start the engine with the gas pedal down until it just dies out or would it be okay for me to just pull the filter the way it is?