The car is an '87 Turbo II which has been sitting for 6 years.

August 4-15/14
- Driven around the community every other day for a total of 4kms there and back, no issues

Tuesday, August 19/14
- It died in the middle of the road about 6km away from home
- I had to get the battery boosted and it died once again pulling into a parking lot close by
- I had a fresh battery dropped off and it died 3x's on the way home about 5.5km away

Thursday, August 21/14
- I drove it to my friend's house about 1.5km away and it died
- Cranked it numerous times, no luck (it was acting as if you tried to crank the car without the intercooler on or would only crank)
- Charged the battery for 30 minutes and started er up
- Car off: +12.5v / car running: high 14v, low 15v
- After letting it idle, the voltages gradually dropped to 12
- Engine was vibrating like crazy and the RPMs were bouncing around 500, eventually shutting off the engine (would drop RPM, raise RPM, drop, etc)

Friday, August 22/14
- Luckily drove the car back home from my friend's house.
- It was about to die again in my garage from idling so I just shut it off

At this point, I thought I had discovered that the engine was misfiring because I did pull a spark plug at one point last week and they needed replacing. I no longer saw it to be a battery/alternator issue since the battery was good and the alternator was charging the battery and withstanding a load (a/c and headlights on)

Saturday, August 23/14
- I had bought new spark plugs and wires it turns out I had T1 and T2 crossed which I assume was the cause of the misfire
- Started it up and let it idle, voltages were fine didn't see any signs of it dying
- Ran it down my street, not even 1km away and it dies at the end of my street after I went in boost

I did notice before it died and I was rolling down the street, all idiots lights went on and I heard 3 beeps (I think, but definitely heard beeping) ~ This had also happened on Tuesday when the issue started to occur

- Checked the battery, voltage was +12.5
- Started the car again and turned around to head back home, it dies just before my drive way.
- I was in boost at least 2x's before it died (died right after boost kicked in the second time)
- Gave it a few minutes and it started again, but I had to keep revving as I was going up my driveway so it doesn't die
- Died right after I parked it and tried to let it idle
- Started it again shortly after and it just dies, unless I keep the RPMs up

Other factors to consider:
- Coolant and oil have yet to be changed. I plan to change it if the car can ever run long enough to warm up the engine.
- Has a fuel pump cut off switch
- 202160 original kms. Rear rotor has excellent compression. I did the poor man's test and I got three strong even pulses.
- Oil pressure gauge reads between 4-8 kg/cm2
- There's at least $40 worth of regular gas in there (will replace with premium once I get the car insured), but the gas gauge does not work.
- I had the TPS previously adjusted to idle around 750 RPM, now it seems to be idling around 1k unless it starts to die down
- In those 2 weeks of driving issue free, I wasn't able to redline, it would hesitate around 4k RPM but on Tuesday and thereon after, I'm able to redline or hit a higher RPM before shifting without hesitation


I know it's long, but at least I've kept it in point form and listed everything that caught my attention What should I look into now? Fuel? Oil? Not looking for a tutorial on how to fix it, just looking at what I should spot next and hopefully find that to be the culprit. I'll post each finding in hopes to narrow it down, and I can provide videos if need be.

 

the answer is in your first sentence.
Change your Fuel filters( one in the tank and one under your feet,under car,driver's side)

 

When the voltage dropped to 12 volts what was the idle speed, and what was the speed when the voltage was higher?

 

When the TPS was properly adjusted more or less around 750 under the standard 14-15 volts. When this issue occurred, around 1k (same volts)

When it was dropping to 12 volts, it would idle more or less around 500, gradually bouncing at lower RPMs and eventually 0.

 

Am I looking for two different parts or the same? Because I inquired for the filter on the high pressure side, which my local parts store has. I just don't know how to explain the filter on the low pressure side, since in the FSM, it just looks like a piece of woven material lol can't find the part number for that one

 

They are different parts. One easy to access while the other one is the woven sock in the fuel tank itself.

The voltage cannot be sustained when the idle drops to 500 rpm and this is why you see the voltage drop off as the voltage is a function of engine speed to a point. The alternator needs the idle speed to be close to 750 rpm for it to output the proper voltage. You might want to check the alternator belt tension to see if there is slippage causing your problem. It's a long shot, but if there is slippage then there will be less voltage created and lower voltage will cause running issues followed by the car dying out. Again, it's a long shot.

 

That's what I thought too so I had tightened the belt a bit and there was still an issue.

For the filter in the fuel tank, am I just asking if they have a sock filter for the fuel tank? Are they universal?

 

Thursday, August 28/14

I had changed the main fuel filter and cleaned off the in-tank filter and here are the results:

First Attempt
- Died down instantly upon starting and reaching 1k RPM

Second Attempt
- Started it up again, but kept revving and it managed to idle around the 10 minute mark (idling at 1.5k
- Reading 15.3v at idle
- Drops to 13.3v with headlights turned on and starts bogging
~ it wasn't like this before, it would usually read around 14v with a/c and lights on
- RPMs started to drop to 1k, but the volts were still high 15's
- Revved to boost, started dying down, died.

Third Attempt
- Almost identical to the second, but didn't idle for too long as I was revving it to boost and when I hit 7.5k RPM it just died

EDIT: On the third attempt, it had only died because a hose off the intercooler blew off. Man, I seriously have to option out for metal pipes or something, that always happens to me when revving to high RPMs

 

I finally got it to work! The hose on the back of the intercooler needed to be stupidly tight. It was finally idling for the longest time, no idle/voltage issues.

Idle: 14.3
Load 1 (only headlights) - Mid 13
Load 2 (headlights and a/c) - High 12's, gradually dropping

I think it's time to upgrade to a better alternator!