What happened? -- S70 T5 140K

gswede · Post by **gswede** » 17 Apr 2016, 07:06

I always keep a paper clip along with a few fuses and a torx bit kit in glovebox

mar601 · Post by **mar601** » 17 Apr 2016, 07:09

by the way has anyone heard of someone replacing this relayand still having problems (stalling etc) -- it runs fine being jumped without an issue but that is just a wire. Like I say, i saw some odd circuitry in the relay (weird) that may be a part of something back and forth with the fuel pump? wonder if those contacts are 12v on/off to the coil or something else. -- ordered the new relay so guess I'll find out.

gswede · Post by **gswede** » 17 Apr 2016, 07:17

There are many things that can make these cars stall. Most commonly vac leaks and also the dizzyhead being full of water/corrosion.
Faulty plugs and or spark wires arching. Coil wire to close to maf wire etc. Evap hoses broken or faulty evap valve can also lead to vac leak.
Hardened o.ring on vac three letting air in post throttle plate. Bust rubber vulking on pipe pre throttle plate going to idle valve. Sticky idle valve. Dirty throttle plate. Bad ground connector or to much resistance in either main ground or positive lead.. Bust FPR or hose going to it. Internal leak on fuel pump due to bad hose clamps on riser hose inside pump. Clogged fuel filter. Clogged Cat or exhaust leak pre O2 sensor. Leaking IM gasket, same with throttle plate gasket..to name a few potential sources

Sommerfeldt · Post by **Sommerfeldt** » 17 Apr 2016, 14:01

I suppose this might help you, since you're proficient in electrical stuff? I have no idea what's going on in here, but I'm an idiot with electrical stuff.

- S

mar601 · Post by **mar601** » 18 Apr 2016, 06:46

Look at that later but after I posted that, wasn't thinking -- I'm sure the cpu is talking to the relay -- "on and off when I tell you to". Not a mechanic so i keep forgetting cars have microprocessors now (I'm an old fart). I'm sure that's what's happening. Another reason to not screw with this relay, and others possibly. Ordered mine new off ebay for 26 bucks, can't beat that.

mar601 · Post by **mar601** » 18 Apr 2016, 06:49

well yeah -- duh, see the purple lead from the ECU?

mar601 · Post by **mar601** » 18 Apr 2016, 06:50

the ecu probably sends out an analog voltage that will have trigger points (the relay circuit) -- on now, off now

Sommerfeldt · Post by **Sommerfeldt** » 18 Apr 2016, 11:48

Glad you could make some sense of it. I've never been able to understand electrical stuff - I'm not half bad with mechanical things, because I get "this goes bang, so that goes down and then that goes round and round", but electrical stuff just goes right over my head.

Good price on that new relay, btw. Would be double that around here.

- S

What happened? -- S70 T5 140K

Re: What happened? -- S70 T5 140K