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Old 03-02-2014, 12:17 PM   #1
curlyman520
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1998 Impreza RHD
230

Default 98 gf8 ej20k runs fine then cuts out and stalls

Hi
The car is a 1998 gf wrx sti, so the other day it started to hesitate and cut in and out. It runs fine lots of power and seems to idle right around 750 to 800. Once you are out driving around out of the blue it will start to loose power and cut in and out almost stalling and it did stall a few times but restarted and drive along then it jumps around again, no mods to the car basically stock, new rad and hoses, so nothing added. I cleaned the maf and it seemed to run smoother but then it acted up again within half and hour, the light came on a few times but went out and does not stay on. Any ideas where to look or what steps to take would be helpful or if someone had an obd2 I could borrow up here in Kelowna.

Thank you Curlyman
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Old 03-02-2014, 11:31 PM   #2
Smoke
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95 V4 STi-RA swap
Stage 49.8

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Does it do it while accelerating at a high rate?
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Old 03-03-2014, 12:28 PM   #3
pmugabi
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Default

Also, that car is OBD1, you read the codes by connecting the black under dash connectors and reading the CEL flashes.
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Old 03-03-2014, 12:55 PM   #4
curlyman520
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230

Default

First thank you for the replies
Well drove the car after looking everything over and cleaning the maf connections, the car ran great for about an hour then it just started to cut out again, it doesn`t matter at what RPM range either and when I come to a stop and depress the clutch it almost stalls. I rev it up and it revs ok then take off and it cuts out in cuts back in and out.
I was kinda thinking fuel filter but it seems so intermittant, also it just started doing it after I installed a new rad, maybe just odd coincidence. It starts right up eveytime drives fine gets up to full turbo temp and then it kinda randomly becomes jerky cutting in and out.
Any help in direction is good for me.
Thanks
oh not sure if it holds any codes but I will have to have my wife help me read the morse code she`s smarter than I.
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Old 03-03-2014, 12:59 PM   #5
curlyman520
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It cuts out randomly, it does it at all throttle positions and then it runs fine, I shut it off then restart and it dives fine for a bit then away it goes again.

Thanks for the help
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Old 03-03-2014, 01:03 PM   #6
vicious7
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1997 Ver.3 WRX STI
Glacier White

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Check the turbo inlet pipe. There is a chance that there may be a tear where the pipe connects to the turbo so check underneath. And while you're at it, check all the hoses.
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Old 03-03-2014, 04:39 PM   #7
dpacro
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it sounds like i problem i had with my mr2. it was the coil ... maybe try an other one.
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Old 03-03-2014, 08:58 PM   #8
wrxr4ti
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I had this problem with my 1998 ej20k, A new MAF took care of everything for me.
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Old 03-08-2014, 12:29 PM   #9
curlyman520
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Default Fixed It

For all those who read this, I took the MAF apart and resoldered all the connections and it works perfect.

Curlyman
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Old 03-09-2014, 07:21 PM   #10
Rally2
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Thanks for the followup!
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Old 03-10-2014, 01:31 PM   #11
eludeauthority
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Good to know it was the MAF just in case any of us run into that issue, thanks!
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Old 03-11-2014, 12:06 AM   #12
Smoke
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Stage 49.8

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Great that you figured it out. I had the same problem in a way, but it was only when I was accelerating. I cleaned the MAF and changed the coilpack and it was up and tearing it up again.
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Old 03-15-2014, 04:29 PM   #13
alter_
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right on that it was the maf - in the future go under your dash and find the green plugs .. plug them together and turn the car to the on position. Your check engine light will then flash the codes.

I had to do this to figure out that my vss was bad.
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Old 04-06-2014, 05:31 PM   #14
Jaxx
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Subaru-less :(

Default

so i too have been having this problem. i figured that i may as well try what curlyman
described

#1 do not remove the screws!!
the top is held in place with silicone cut it off with a razor blade and pop the lid out

under the copper shield you will see

i took a fine point soldering iron and hit the 3 points where the signal comes in (now you see why not to remove the screws)
the 3 points where signal comes into the board
and the 4 points to sensor and heater
cleaned all silicone out and re-soldered the copper shield back in place then used rtv to seal the lid ..

rtv is curing will report back
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Old 04-12-2014, 11:48 PM   #15
Jaxx
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Subaru-less :(

Default

So it worked like a charm. No more drop outs, runs like a champ...

not sure i fit was the re-soldering or the maf cleaning but i suspect it was the soldering
definitely worth attempting vs buying a 300 part
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Old 04-21-2014, 09:32 PM   #16
halfassedsubie
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Had the same issue new maf fixed it thanks
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Old 04-25-2014, 12:24 AM   #17
SJOGUN
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Default MAF cleaning

What is the best product to clean my MAF? I know they are very sensitive. I am having hesitation when cold from 3/4 to WOT. I thought it was due to an incomplete, but functional, tune, but I think I should clean/check solder on my MAF. Any additional info would be greatly appreciated.
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Old 04-28-2014, 03:33 PM   #18
Jaxx
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Subaru-less :(

Default

go to the parts store and ask for "maf cleaner"

some maf's are more sensitive than others
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Old 04-28-2014, 04:02 PM   #19
SJOGUN
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Got some, cleaned it according to the instructions. No effect. I hope my issue is with the tune, and not a burned exhaust valve or something..
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Old 08-21-2020, 02:48 AM   #20
Vancouver98STi
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1998 JDM Impreza STi
V4 GF8 White

Arrow Need advice on MAF sensor repair and possible "scaling" issues

Forgive me for resurrecting an old thread, but it's an informative one, and it covers something I'm currently dealing with.

I had suspected the MAF sensor was the culprit when the EJ20K in my '98 JDM Impreza STi began running like crap, to the point where it was undriveable. It's obvious the three MAF sensor terminals have been re-soldered previously (looks like a very poorly done job!), and I suspect a connection (or two or three) are loose again.

The car's now at a highly recommended local shop. In discussion with the mechanic who's checking over my engine, he's stated he's concerned that although re-soldering may regain continuity at these connections (which will allow the MAF sensor to at least read again), the "scaling" may not be correct. He's recommending running a wide-band O2 sensor, basically to warn of a lean condition and to prevent destruction of the engine.

This is well beyond my level of expertise. Any thoughts on this "scaling" issue?
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Old 08-21-2020, 09:36 PM   #21
binny
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Default

Quote:
Originally Posted by Vancouver98STi View Post
Forgive me for resurrecting an old thread, but it's an informative one, and it covers something I'm currently dealing with.

I had suspected the MAF sensor was the culprit when the EJ20K in my '98 JDM Impreza STi began running like crap, to the point where it was undriveable. It's obvious the three MAF sensor terminals have been re-soldered previously (looks like a very poorly done job!), and I suspect a connection (or two or three) are loose again.

The car's now at a highly recommended local shop. In discussion with the mechanic who's checking over my engine, he's stated he's concerned that although re-soldering may regain continuity at these connections (which will allow the MAF sensor to at least read again), the "scaling" may not be correct. He's recommending running a wide-band O2 sensor, basically to warn of a lean condition and to prevent destruction of the engine.

This is well beyond my level of expertise. Any thoughts on this "scaling" issue?
As long as you resolder properly there will be no issue the sensor itself is very durable
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Old 08-22-2020, 04:13 AM   #22
Vancouver98STi
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1998 JDM Impreza STi
V4 GF8 White

Smile It's great to have a soldering master as a friend!

Quote:
Originally Posted by binny View Post

As long as you resolder properly there will be no issue the sensor itself is very durable
That's good to hear. I hope you're right!

Here's a couple of Before and After shots. This first one shows a really bad previous re-soldering job which occurred before my possession of the car. Looking at this, I'm surprised the engine ever ran properly!




And here's the job my buddy, an electronics wizard, did. What a difference in how it looks... and hopefully, in how it works!




Our only slight concern is that the ceramic insulator on the right has a hairline crack, which can be seen in both images. However, the crack doesn't appear to have affected the ceramic's insulating properties. The plastic cover was well sealed when re-installed, so moisture shouldn't be an issue.

The shop the car is in will be closed until next Wednesday, so it'll be a few days before I can report the results of this procedure.
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Old 08-24-2020, 09:15 PM   #23
Vancouver98STi
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Join Date: Dec 2016
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Vehicle:
1998 JDM Impreza STi
V4 GF8 White

Smile Drum roll please...

Quote:
Originally Posted by Vancouver98STi View Post

The shop the car is in will be closed until next Wednesday, so it'll be a few days before I can report the results of this procedure.
I was contacted by the fella working on my car. He said he was dropping by the shop (a couple days early) to pick something up, and he asked me how confident I was that the car would run properly if he was to put the MAF sensor back in while he was there. I said I was quite confident... as heck, look at those Before and After shots!
And the news is... it's alive !!!
I had suspected that damn MAF sensor all along. I guess I didn't act on my suspicions earlier, as it was obvious that the MAF sensor had been opened up previously... and I had made the assumption that whomever had been in there before had done a decent job re-soldering the three terminals. Well, the pictures in my previous post speak for themselves. The earlier re-soldering job was absolute crap. Thankfully, my buddy is an expert at electronics, and his soldering abilities are top notch.

I'm so happy that the car is now running properly again. I took it easy on the drive home... hey, I've got to get used to RHD again , but the STi felt really good. Tons of power. Next summer, hopefully a return to autocross!
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Old 11-04-2020, 10:46 PM   #24
Vancouver98STi
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Join Date: Dec 2016
Chapter/Region: VIC
Location: Vancouver BC Canada
Vehicle:
1998 JDM Impreza STi
V4 GF8 White

Thumbs up Complete with resurrected images!

Following is a post from earlier in this thread. So why am I copying and re-posting the whole thing? Because the images are missing from the original post... but through some internet sleuthing, I was able to find them! I felt the content of the post, along with the reinstated images, was worthwhile preserving for anyone who might be experiencing this same issue.

Quote:
Originally Posted by Jaxx View Post

so i too have been having this problem. i figured that i may as well try what curlyman described

#1 do not remove the screws!!
the top is held in place with silicone cut it off with a razor blade and pop the lid out




under the copper shield you will see




i took a fine point soldering iron and hit the 3 points where the signal comes in (now you see why not to remove the screws)
the 3 points where signal comes into the board
and the 4 points to sensor and heater
cleaned all silicone out and re-soldered the copper shield back in place then used rtv to seal the lid ..

rtv is curing will report back
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