Car stalls. Hard start. MAF questions

surfbug1 · Post by **surfbug1** » 25 Mar 2022, 10:20

Hello,

98 Volvo V70 Glt

Car will shut off at lights and when idling. Just plain cuts out, no sputtering just drops off and engine stops

Tried the (disconnect the MAF trick) and she starts right up.

In fact I can drive with the MAF disconnected, but I know that's bad.

Any way to clean the MAF? or should I just go to a junkyard and buy another to replace it.

I'm not buying new unless needed, car has 245k miles.

Thoughts or guidence please.....

Thanks!

Al

454cid · Post by **454cid** » 25 Mar 2022, 11:58

Assuming it's a heated wire MAF and not the other technology that Toyota/Lexus used for awhile you should be able to clean it. They sell "MAF Cleaner", but I usually use contact cleaner for electronics. I suspect it's the same stuff.

It would be interesting to see what the PCM/ECM sees. When I had one go bad on my truck, it was reading way too low, like a 2 instead of a 9. I don't recall what the units were.... mass/time, possibly.]

EDIT: turns out Volvos use "heated film" MAFs and those are not easily cleaned and often said to be not able to be cleaned. My GM MAF is a heated wire, or possibly cold wire design, which is easily cleaned.

Post by **ThaddeusTheBold** » 25 Mar 2022, 12:02

Contact cleaner is not the same as MAF cleaner. If you use contact cleaner on the heated wire element of your MAF, you will destroy it.

Ask me how I know..... ugh

Post by **abscate** » 25 Mar 2022, 15:37

You want pure hexanes and heptanes to clean a MAF, after which you will continue to seek the problem

454cid · Post by **454cid** » 26 Mar 2022, 02:38

ThaddeusTheBold wrote: ↑25 Mar 2022, 12:02 Contact cleaner is not the same as MAF cleaner. If you use contact cleaner on the heated wire element of your MAF, you will destroy it.

Ask me how I know..... ugh

I haven't had a problem with it. I've never ever purchased MAF cleaner. Maybe Volvo MAFs are different somehow? I've never cleaned my Volvo MAF, just my GM Delphi MAF.

EDIT: turns out Volvos use "heated film" MAFs and those are not easily cleaned and often said to be not able to be cleaned. My GM MAF is a heated wire, or possibly cold wire design, which is easily cleaned.

Post by **jreed** » 26 Mar 2022, 06:40

CRC makes a heptane based MAF contact cleaner. I used it once about 10 years ago on my '97 855's MAF and it caused no apparent harm.
I don't know if the '98 has the same automatic idle control valve as the '97, but if it does it might be worth while to clean it out.

Post by **erikv11** » 26 Mar 2022, 09:39

abscate wrote: ↑25 Mar 2022, 15:37 You want pure hexanes and heptanes to clean a MAF, after which you will continue to seek the problem

This. MAF cleaner is really good for selling MAF cleaner. Not much else. The MAF is almost always just shot, unless e.g. you can see junk on it. I'd get a junkyard MAF. If you can't find one PM me I may have one.

IAC is the same on a 98 and 97, jreed's idea to clean it is a good one.

surfbug1 · Post by **surfbug1** » 31 Mar 2022, 10:00

jreed wrote: ↑26 Mar 2022, 06:40 CRC makes a heptane based MAF contact cleaner. I used it once about 10 years ago on my '97 855's MAF and it caused no apparent harm.
I don't know if the '98 has the same automatic idle control valve as the '97, but if it does it might be worth while to clean it out.

Thanks ! I clean d the MAF, didn't make a difference.

How do I clean the idle control valve?

I will start searching, but if you have any ideas/steps/advice that would help!

Al

surfbug1 · Post by **surfbug1** » 31 Mar 2022, 10:22

Here is more info

When car stall, it just drops out. Can be hot or cold.

And on every startup , even if hot or cold, the car does this:

First try
The engine will catch at 700 rpms, then stall

Second try
Engine will catch at 400 rpm then stall....

.
I keep the starter enganged, the key full on, and the engine will then catch at 900 rpm and then run fine.

And it happens every time. Even if I just start the car and it's running fine. If I shut the car down, it will have to be started like the above procedure shows

Also, when driving at highway speeds, the engine will drop out, and then come back on in about 5 seconds. (Moving 60 mph prolly starts it up again)

Tried to read obd codes, my port is dead. I check fuse #5 under the hood, it's fine and I even replaced it to be sure .

So, maybe next easy thing to do is clean the IAC.

I cleaned the MAF sensor, and no difference.

Thank u for the help

Al

Post by **misha** » 31 Mar 2022, 12:59

Maf or fuel delivery(fuel pump,filter,fuel pump relay).
But...if it runs good with Maf disconnected and not stalling or cutting out...it's bad Maf.