Dying and loss of power getting worse day by day

[Han-Tyumi]

1990 Vanagon Carat. Been chasing my tail around this issue for months, and it just keeps getting worse.

The issue started a couple months into our ownership of the van. It first started by every other morning we would start it and run for a second, then turn off and start right back up and be fine the rest of the day. It progressed to happen every morning, then every time we would start it. Now it's turning off while driving, coming to a stop, losing power out of nowhere and sometimes will not start back up for awhile. It's basically to the point where we can't drive it down the street without it dying 2-3+ times.

These are all things I've replaced trying to get this figured out:
Coolant temp sensor
Spark plugs
Spark wires
Distributor cap
Distributor rotor
Fuel pump
Fuel filter
Air filter
Ignition switch
Sanded and cleaned all grounds
New battery
.
.
Things I've replaced during my ownership of the van unrelated to the issue:
Water pump
GW Fuel tank reseal kit
Fuel sending unit
GW Square to Round headlight conversion kit
T3 Technique HD anti-roll bar
Powerflex polyurethane steering rack bushings
Radio antenna
Aftermarket stereo and front speakers
ST Suspensions Sport Lowering Springs
Oil cooler seal
.
.

I am thinking ECU, Fuel Injection or Fuel Pump relays, AFM or maybe FPR. What do you guys think? I'm running out of money to just throw parts at it haha

[THINGONER]

A possibility might be-gunk inside fuel tank blocking fuel delivery (outlet hole)-or gunk in fuel line.

[AceTaylor]

Check for a clogged catalytic converter.

[DanHoug]

you've replaced a lot of the 'consumables' that typically go wrong but my suggestion would be to go back to basics....

- do a compression test to see what your numbers are

- do a fuel pressure test. you've replaced pump and filter but the tank filter as has been suggested could still be giving issues.

- check your ignition timing

with these 3 basic pieces of information, you can go on from there. i'd personally also clean the relay sockets with Caig Lags DeOxit 5% spray for the ECU/fuel pump in the black case on the left side of the engine. then treat the ECU connector. if it is still wonky, suspect an ECU failure.

-dan

[E1]

See if you hear rattling on throttle down.

If so, have someone rev it while you pinpoint if rattle is from catalytic converter. Ours just clogged three weeks ago, we live on the road and have a new one ready to install. It seems it cleared itself for now, but will swap asap.

Edit: and Oh, try swapping the coil and fuel pump relays, and see if it changes anything.
_________________
‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[jberger]

I would start by checking the distributor.
1. Wires to hall sender. The insulation get brittle and cracks
2. Ground wire connector
3. endplay in rotor shaft- the shims can wear or break and fall out causing too much endplay in the shaft. This messes with the hall sender signal.

J

[WestfaliaMike]

Check your coil. Feel if its getting hot. The coil looses the ability to generate the voltage need for the correct spark when they start to faiil..
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1981 Vanagon Westfalia
1983 Vanagon Passanger (Parts Vehicle)
2016 Passat TSI

[Han-Tyumi]

So, after trying 3 coils, 2 ignition switches, coolant temp sensor, spark plugs, wires, distributor cap and rotor, cleaning all electrical connections, sanding and cleaning all of the grounds, putting the Vanagon Syndrome AFM wiring harness fix on it, fuel pump, fuel filter, pressure tests etc.

Turned out to be a dud coolant temp sensor and the O2 sensor together. Coolant temp sensor was freaking the computer out and O2 sensor wouldn't ever turn on to trim the fuel mixture, so I popped a new coolant temp sensor in and the issue got significantly better, but it still wanted to die at operating temp. O2 sensor still wasn't trimming the mixture after temp sensor started losing resistance as it should gradually as it warms up. New O2 sensor and it's running like a dream now! Especially with all of those new parts I replaced for no reason 😅

[Robw_z]

[cmayna]

Glad to hear this got resolved. Lots of good info here for others to learn from.
_________________
'90 Westy / automatic.
If I'm not working on the camper or my '50 Chebbie truck, I'm either fishing with the wife or smoking Salmon.


Craig

[Wildthings]

Doing the steps for the electrical diagnostic as given in the manual would have pointed out the problem in just a few minutes.