1998 V70 Infamous random stall no start. I have some questions

V70buddy · Post by **V70buddy** » 03 Jan 2019, 02:26

Also forgot to mention I fixed the vacuum leak at the intake.

Post by **abscate** » 03 Jan 2019, 04:37

Very rare for O2 to cause stalling. It doesn't even start regulating mixture until it gets hot so no impact on starting.

The definitive way to diagnose the fuel pump relay is to monitor fuel pressure at the rail. You can borrow a fuel pressure tester from auto parts chain like Advance. I own one and it has helped me 3 minute duagnose 3 bad fuel pumps over the years, and another 7 null diagnostics give or take

greg850r · Post by **greg850r** » 08 Jan 2019, 20:29

I just saw an N/A 850 doing the same thing and it turned out to be a hard to see cracked vacuum hose in the EGR system (not vacuum line, one of the 1/2" ones). Crack opens car dies and wont start. Crack closes it runs.

V70buddy · Post by **V70buddy** » 30 Jan 2019, 00:33

Okay guys I thought the problem was fixed with a new fuel pump relay seeing as how it didn't happen again. But I'm back. This past Thursday IN THE RAIN for the 4th time it did it to me. So it has got to be rain related. Not even in the heavy snow I experienced today in Maryland it had no effect. I have bank one sensor one o2 code I've had this whole time and I have a Bosch replacement, also a MAF code. I know y'all are thinking oh it's gotta be the maf. You may not be wrong as I have not replaced it but when it happens I unplug the maf like I've stated before and it still won't start until later. Would the code I have be because I have unplugged it and haven't cleared a code or would a good MAF make my car clear it? If it should clear on it's own that'll be my culprit most likely. I pulled a fuel pump out of an 850 sedan at the yard does it matter that it was a sedan or am I stupid? I just couldn't seem to find any definitive info on that topic online so I figured must be universal? So as of now I have the 02 I need. A new fuel pump relay. A used fuel pump with 100k on it. I'm about to order the fcpeuro Bosch ignition kit as well to put in. If someone could answer my questions I would appreciate it highly you guys are great and I appreciate all the insight. I have no issue performing any job just save save save. I've got a baby on the way so money needs to be spent wisely. Thing still runs top when it doesn't rain.

V70buddy · Post by **V70buddy** » 30 Jan 2019, 00:36

greg850r wrote: ↑08 Jan 2019, 20:29 I just saw an N/A 850 doing the same thing and it turned out to be a hard to see cracked vacuum hose in the EGR system (not vacuum line, one of the 1/2" ones). Crack opens car dies and wont start. Crack closes it runs.

What exact hose is it you're mentioning boss? If it's the one next to the intake that may be my exact problem because I'm aware of that and wouldn't expect any pcv stuff to make it stall. I don't have emissions so it's not a problem for me. Unless obviously it makes me stall in the rain lol

Post by **abscate** » 30 Jan 2019, 05:48

You have new coil, cap, rotors, spark plugs, and plug wires on now? Those are all parts that won’t like humidity when they age

Post by **erikv11** » 30 Jan 2019, 11:00

To answer your actual questions, I think there were three of them:

Unplugging the MAF (while the car is turned off) should fix the problem right away, if the MAF is the issue. There's no double jeopardy from setting a code. If you still have to wait until things dry up then more likely ignition as abscate says. I'd look under the distributor cap for moisture. While you are at it, is the cam seal bad under there?

The MAF code you have is likely because you unplugged it, yes. Reset all OBD II codes by disconnecting the battery briefly (but make sure you have the radio code!).

Yes, the P80 sedan and wagon have the exact same fuel pump.

greg850r · Post by **greg850r** » 07 Feb 2019, 10:59

The 1/2" hose on the right side of the red box was coming loose from the round control valve. Vacuum leak here caused it to die and no start.

: 94 850.jpeg (68.24 KiB) Viewed 1220 times

V70buddy wrote: ↑30 Jan 2019, 00:36
greg850r wrote: ↑08 Jan 2019, 20:29 I just saw an N/A 850 doing the same thing and it turned out to be a hard to see cracked vacuum hose in the EGR system (not vacuum line, one of the 1/2" ones). Crack opens car dies and wont start. Crack closes it runs.
What exact hose is it you're mentioning boss? If it's the one next to the intake that may be my exact problem because I'm aware of that and wouldn't expect any pcv stuff to make it stall. I don't have emissions so it's not a problem for me. Unless obviously it makes me stall in the rain lol

dj_v70 · Post by **dj_v70** » 07 Feb 2019, 13:49

In the last 30+ years, I don’t believe that I have ever had a rain related performance issue that wasn’t either distributor cap or wires. But, Abscate is right it could be coil also. 90% probability it is a high voltage arcing issue due to high humidity.

Take an empty windex bottle or equivalent and fill with water. Spray in those specific areas and see if you can re-create the issue.

WhatAmIDoing · Post by **WhatAmIDoing** » 07 Feb 2019, 18:12

I've had heavy rain / high humidity mess with aftermarket fuel pump relays as well as wires and distributor.

1998 V70 Infamous random stall no start. I have some questions

Re: 1998 V70 Infamous random stall no start. I have some questions