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intermittent power loss

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blackej7

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Discussion starter · #1 ·
Im having an intermittent power loss problem with my 93 240. The engine is a black top sr. Motor is stock, all thats done is a greddy bov and an ARC smic, blitz downpipe, apex exhaust. Im using a homemade mbc, and its set around .7 bar.

The motor runs/idles fine for the most part. However, every so often (which is starting to happen more often), ill be accelerating, and the car will have barely any power. If i floor it, my greddy boost gauge reads .7 bar, but the car barely moves. This only happens once in a while, but since its happening more and more, it seems like a part/sensor is starting to fail. It kinda feels like its bogging, but not really... just really slow. If i pull over, shut the car off and let it sit for a minute or two, it will drive fine for the rest of the day.

What could be causing this problem? Again, the car drives pretty good, but now maybe once or twice every few weeks, this starts to happen.

Any ideas?
 
#3 ·
any other symtoms? (only happen when ur problem occurs)
does ur car sputter (shaking) when idle or when u hit on the gas?
does the exhaust sound like a Subaru?
does it backfire more than normal?
smell gas more than normal?
it u have the above problems then replace the coilpack.
 
Discussion starter · #4 ·
Its really hard to tell what conditions this problem happens. Sometimes it happens after 10 minutes of driving, sometimes it happens 1 hour after driving.

My car has never had a problem idling, even when this problem occurs.

Exhuast kinda sounds like a Subaru at start up, but once its warmed up, it sounds normal.

Does not backfire often, however i do smell gas more than normal.

Again, I only notice this under load. The car still idles fine. If I notice the powerloss, as long as i dont boost, the car still drives OK.
 
#7 ·
well i had the same symptoms as you, and i couldnt figure it out. then one day it got so bad that i was running on 3 cyls... so i proceeded to unplug my coils at idle to narrow it down to the culprit cylinder. coil tested good so i pulled out the injector and sure enough the lower o-ring had a big gash.
 
Discussion starter · #8 ·
see the thing about that is, this problem only happens under load. When I feel the power loss, ill drive untill i can pull over. when im sitting there, the car idles fine. If an injector were bad/leaking or whatever, wouldnt the car idle differently or worse?
 
#9 ·
blackej7 said:
see the thing about that is, this problem only happens under load. When I feel the power loss, ill drive untill i can pull over. when im sitting there, the car idles fine. If an injector were bad/leaking or whatever, wouldnt the car idle differently or worse?
Click to expand...
yeah it was the same thing for me. the car got boggy in boost only. whats weird is that it would still boost (gauge reading 8psi) car just didnt go anywhere.
 
Discussion starter · #12 ·
well this problem started a long time ago, before the car was even mine. I think since i drive it more than the previous owner did, im seeing it more and more often.

like ive driven the car for 3 days with no problems. but it could start acting up whenever....

ill be taking a look at it this weekend.. so well see!
 
#13 ·
I think this problem happens to me too. Car feels fine sometimes and sometimes its just boggy. I know I have a leaky injector though because I can smell the gas at idle/stop lights sometimes and I stuck my nose in between the cylinders and could definately smell hardcore gas.
 
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#14 ·
Does you car run strong the rest of the time? I mean strong not just "ok". Iv seen SOOO many SR's where the timing is off due to the fact that they are using the loop at the back of the head to time it. Time it off the #1 cyl directly!
 
Discussion starter · #15 ·
Yeah, if i notice the problem, ill just pull over for a few minutes, and let it sit. when i start it back up again, the car runs perfectly fine.

btw, Its been over a week since ive felt any sort of powerloss. I feel if it were a timing issue, id see a problem more often then this, right?
 
#17 ·
blackej7 said:
Yeah, if i notice the problem, ill just pull over for a few minutes, and let it sit. when i start it back up again, the car runs perfectly fine.

btw, Its been over a week since ive felt any sort of powerloss. I feel if it were a timing issue, id see a problem more often then this, right?
Click to expand...
Thats not always the case as the ECU is always trying to make adjustment to get the car to run better. Did you set the timing on the car or did someone else. I REALLY think its worth it for you to rent a timing gun (if you dont want to buy one) and check it yourself. All you need is an old spark plug wire, some electrical tape, and the gun. Check the FSM for detailed directions on how exactly to time it without using the timing loop at the back of the head.
 
Discussion starter · #20 ·
The timing was set to factory spec when the engine went in. I havent checked it recently, but if i can find a timing light ill definately try to check it....

also my cat is gutted...

lol its almost been 2 weeks since ive felt the power loss..... the weather has been cool lately, but now its back up to 70-80.... but i doubt weather is a factor here...
 
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