1996 850 turbo, from no start to starts/dies

FluffyWaffle · Post by **FluffyWaffle** » 18 Oct 2020, 16:58

Hey all,

My 850 turbo has been sitting for approximately a year in Ohio. Only 130k miles. This past fall I attempted to start it and received nothing but a click. This led me down a long list of tests and fixes, including:

1) Replaced oil/filter, fuel, primed cylinders with a cap of oil, charged battery
2) Turned the key - no cranking
3) Removed starter, tested at AutoZone (passed), cleaned electrical terminals on both starter and incoming wires
4) Replaced starter - success! Cranking!
5) Examined spark plugs - determined they were old, replaced all 5. Tested all 5, they're functional.
6) Meanwhile, ran a compression test. Every cylinder is low to some degree, saw improvements after throwing in a cap of oil.
7) Found the fuel filter had a puncture in it. Replaced.
8] Turned the key - temporary success. She'll start, run for a while, then die in 5-10 seconds.
9) Fashioned a jumper for the fuel pump 103 relay. Car runs similarly as before, dying after a short bit of running.

This is where I'm currently at. The fuel pressure tester I bought at Harbor is garbage and leaks, so I can't adequately test if the fuel pressure drops while running.

Am I down the proper train of thought here, or is there some aspect I might be missing with these symptoms?

Jaydiesel · Post by **Jaydiesel** » 18 Oct 2020, 18:27

Seems like your getting there. But I would now check air issues for the engine. aka. vacuum lines, Mass Air Flow sensor and etc.

FluffyWaffle · Post by **FluffyWaffle** » 26 Oct 2020, 17:51

UPDATE:

I looked at how the car behaves a bit more, and have discovered that the engine will run as long as I want if I'm gently pressing the gas pedal. Engine sounds smooth. But releasing the gas pedal will cause the car to die at idle. Because of this, I'm going to clean the Idle Air Control Valve and see if anything changes.

I also took Jay's input and began looking into the vacuum lines. I have discovered a rupture in a small hose I believe to be vacuum/PCV - it's a very thin tube to the left of the intake manifold, and immediately snakes somewhere behind the manifold or deeper. I'll be looking into replacing the line and likely investigating PCV issues later.

Post by **abscate** » 26 Oct 2020, 19:17

Make sure you are using left and right relative to the car, not the observer

Pictures are worth 1600 metric words

Post by **RickHaleParker** » 26 Oct 2020, 20:16

FluffyWaffle wrote: ↑26 Oct 2020, 17:51 I looked at how the car behaves a bit more, and have discovered that the engine will run as long as I want if I'm gently pressing the gas pedal. Engine sounds smooth. But releasing the gas pedal will cause the car to die at idle. Because of this, I'm going to clean the Idle Air Control Valve and see if anything changes.

Could be dirty throttle unit. Gunk blocking the idle air through the throttle unit effectively choking the engine.

FluffyWaffle · Post by **FluffyWaffle** » 27 Oct 2020, 14:46

UPDATE:

Abscate, good idea on the pictures. Here's one of the hose I was talking about.

: PXL_20201027_203925470.jpg (78.83 KiB) Viewed 630 times

It's the passenger side of the intake manifold, with a tear on top of the larger hose. It runs 1-2 cm deep. I felt around and believe I could feel the "end" of the smaller hose through the tear, so I'll definitely investigate this today.

ALSO, I cleaned the Idle Air Intake Valve. The cleaner took a lot of buildup away and I noticed a smoother, fuller swing in the valve. It may have improved the idle quality in the engine, but it still seems to die after a good 10-15 seconds of idle.

I'll be investigating the throttle body and cleaning it today as well.