Cold Start Idle and Die, Lugging, Horrible MPG - Related?

[Ethan5150]

Our 1984 1.9L Westy has been having some issues lately and we're working through them, as I've learned will be a constant as long as we own this thing.

It's been lugging real bad when driving every once in a while for like 15 seconds at a time. It's also been running real rough when cold (lifter noise, even after adding some Marvel Mystery Oil), and lately it will just die after maybe 15-90 seconds on cold start unless given some gas and kept revving for a few minutes. I cleaned the fuel pump contacts and added some dielectric grease and the lugging while driving hasn't happened since (although it's only been a couple days) - but the cold start issue continues. I start it in the morning and unless I keep the RPMs a bit higher than idle, it will run for a minute or so, then stumble and die. To get it running again requires a specific method of pumping the gas while starting while it stumbles around until it catches. The last VW mechanic we saw recommended checking the air flow sensor and putting some dielectric grease on the contacts - this isn't the same as the O2 sensor right? Where is it?

To add to all this, a couple weeks ago (perhaps the same time of the lugging and dying / cold start issues) I noticed our fuel economy plummeted (from 16+MPG to < 10MPG). Could these two issues be related? Any suggestions? Chevron Supreme is eating me alive right now!

7 months full time in the Westy and counting!

[duderanchero]

when's the last time you replaced your spark plugs/wires? i recently replaced my wires to find that i had probably been intermittently running on 3 cylinders--real bad for fuel economy. you can test the wires with a multimeter. could also be a clogged injector. could be a lot of things (o2 sensor, for instance), but start with the simpler things first, if you haven't ruled them out already.

[Ethan5150]

The clogged injector theory sounds good - it seems like every time I put Seafoam in the tank it runs better for a while. I did put new plugs and wires on about 9 months ago but they were just standard stuff from the FLAPS. Was this a mistake? What's the best way to test the wires? It seems like since this problem is intermittent, this would be difficult to test. Also, seems like it wouldn't get better as the van warmed up, or am I wrong? Suggestions on replacement injectors? $145/per from Van Cafe seems pretty steep... Is there a better route?

[duderanchero]

if the plugs/wires are new and to spec (bosch wires, no platinum plugs), they're "probably" okay. the fact that the problem mostly occurs only when starting would normally indicate something else, but mine was doing exactly as yours is, and the wires were the problem. (if you do ever want to test the wires, check resistance from tip to tip--should be ~6k ohms to the plugs, 2k to the starter, if i recall.)

i should have asked before: does the problem go away entirely once you're on the road? i.e., after a half-hour of driving, when you stop at a red light, does the idle stay relatively steady?

i'm just trying to get as much information as possible, until someone more knowledgeable steps in.

(if you do want to clean out the injectors, mmo can also be added to the gas tank.)

[islandjeeper]

The only way to properly clean and test a fuel injector is to remove them and send them to a shop that will perform the service. I sent mine to http://witchhunter.com/ they charge $20 per injector to clean and flow match them together.

I have tried all the majic poor in the fuel system cleaners and none of them have ever made a lick of difference for me.

If you end up with a bad one when you send them in then you will need to find a replacement. I have a spare set of injectors and you can have them for free if you need a replacement for one of yours if it is bad.

So far I have not had any problems with any of the injectors on my Vanagons. Well....there was one that I could not get to start after sitting for 8 years and all the injectors were stuck closed. After putting a constant 12 volts from the battery on them they popped open and have been working fine since. I am sure they have crusty insides and should be cleaned, but I will leave them alone for now because I plan on removing the engine this summer for a TDI conversion.

The other thing I can think to check that has caused lots of problems on my Vanagons, is the grounds and 02 sensor and wire. The 02 sensor wire has a 2 conductor wire that can short out inside itself intermittently and cause problems. I usually have to run a new wire from the ECU to the 02 sensor to get my problems to go away. This problem usually results in a over rich condition and someone has always removed the cover on the air flow meter and tried to do internal adjustments to lean out the fuel mixture.

Sometimes the problem can be found where the green wire from the ECU attaches to the 02 sensor wire, you can strip a bit back and put a new end on, be careful not to let the two wires touch, one is inside the other, it is a shielded wire, the outer wire is a ground for protecting the inner wire from electrical noise. I have also seen these crimped together in attempt to do the repair which makes the engine run so rich that it will hardly run.

The 02 sensor is in the exhaust on the drivers side and has one black wire going to a connector on a thicker green wire on the drivers side engine compartment.
_________________
Stephen Sunkel
1989 Westfalia Syncro Turbo Diesel

[Ahwahnee]

[Ukekuke]

I feel your pain....I have an 81 westy. I found all of my hoses, my afm boot, and intake sleeves to be leaking everywhere. I had to pull my
deceleration hose just to get it started. My symptoms were exactly as
you describe.

I too was running on 3 cylinders when a friend more versed in air cooled
vw's helped me check my compression. #3 dead. A tiny little bit of mystery oil and it became unstuck. (lucky me),,,,

My bucking was caused by my long ground wire by the ECM. The sheathing was 3/4 stripped away. No more bucking. I then took the
time to clean all of my grounds. 29 out of 30 I found. I don't know if
this is the cause for your headaches but I'd check for compression, air
leaks and check that ground by the ecm. It appeared to have been
chaffed by my fan belt.

good luck

[Ethan5150]

Here's where I'm at:

All plug wires measure ~5.3 ohms
All plugs cleaned and dielectric greased on back tip
- I did notice plug 4 had a bit of oil? on it around the threads - noticeably more than the others
AFM looks OK - flap swings easily, not too dirty, applied dielectric grease to plug contacts
All injectors now have dielectric grease on contacts
- The #4 injector is different than the rest, it's green instead of orange, I also noticed a couple months back when I did my fuel lines that it had a bit of extra plastic at the point of injection which made it look different than the rest, I cut this off - could this be causing my problems? Did I dun mess up?
The O2 sensor and wire seem OK from a quick look

Also, I'm pretty sure there's a very small exhaust leak at the catalytic converter gasket - would this make a difference?

I'll begin reassembly now and see what happens...

[Ethan5150]

OK, completely reassembled and seemed to run great for a minute or so, then started to struggle. Also, is it normal to have a bunch of black crap spray out of the exhaust when starting or does this indicate a problem? Are there any tests I can do while the engine is running to help nail down the problem or should I just start replacing injectors? I think I may have an old set available to test with... As for the MMO in the gas tank, is this going to do anything Seafoam wouldn't have already done?

Thanks for everyone's help!

We're currently in Santa Cruz heading south to Huntington Beach over the next week or so - anyone have a driveway/garage and some spare time to help me finger this out? I'd love to meet up and geek out Westy style!

[Ahwahnee]

[islandjeeper]

When your Vanagon starts running poorly, shut the engine off, wait a few seconds and then restart it. If it runs fine again for a short bit, check that 02 sensor wire. You can not tell if it is bad by looking at it most of the time. You will have to check it with an ohm meter and see if the inner wire is shorted to the sheld. Remove the plug from the ECU, remove the plug from the 02 sensor and put a meter on the inner and outer wires, if you have continuity, your wire is bad. You may have to remove the rubber boot from the end of the wire where it attaches to the 02 sensor wire. You should then see the inner and outer wires they should be green in color. Give that a try and see how she runs.
_________________
Stephen Sunkel
1989 Westfalia Syncro Turbo Diesel

[ftp2leta]

O2.
Unplug, check wire, van side. Look carefully that the shield doesn't touch the main wire near the flat connector.
_________________
Working with rust, grease, dirt and dust is a sad truth.
------------------------------------------------------
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[duderanchero]

[Ethan5150]

Thanks everyone, I'll go through all this stuff. I'm excited to find out about the Vanagon Rescue Squad too!

As of late, the engine seems to start ok most of the time (80% or more) but sometimes it dies after a minute. It hasn't struggled while driving in a while. Once it dies though, even if I shut the van off completely and try to restart it, it really struggles to even start, so it's not like I can just stop, wait a minute then it fires right up - it takes quite a bit of finesse pumping on the pedal to get it out of its stumbling and back to a normal idle. It really "feels" like the injector is getting stuck (dumping too much gas in sometimes, and failing to open others). This seems like it would also explain the very wet #4 spark plug too, no?

Nevertheless, I'm not ruling anything out - I should have replacement injectors to test with in 2 days so I'll go through everything then. I'll keep updating as I make progress. Thanks again everyone!

[duderanchero]

this description would seem to point to something other than the o2 sensor, i think.

is it a bad idea to unplug the afm and/or idle stabilizer while running to see if they're toast?

i still want to know what your idle is like at a red light. is the problem there anytime your foot is off the gas?

replacing the injectors could improve things (hope it does), or it could be an expensive shot in the dark. i really hope you can find someone to take a look/listen--it might save you a whole lot of time/money/uncertainty in the end.

[Ethan5150]

Well, as of late, the problem only exists on cold start, so by the time I'm at a red light, the engine is idling fine.

[Ukekuke]

do you have a strong fuel smell at cold start?

try disconnecting the decel hose and see if it

improves your starting. My81 westy ran good

after warm up too! Did you check your intake

boot for cracks? Remove it and check underneath

for cracks. I struggled for 2 months with this

same symptom.

BTW i'll be in Bellingham this week. i know ur

in cali.

[fredn]

What are the numbers from your compression test?
_________________
1982 Air Cooled Vanagon Carat Weekender Interior

[88formula]

back to basics.
you need air, fuel, and spark.
chances are if it will run, you've got all three.
if it runs like crap, you've got too much, or tool little of one or more.
new plugs and wires, good. next step would be to check resistance through the coil. from the center to term 15 ( or which ever is the positive) and from term 15 (again) to the ground. if its in spec, we can assume proper kv without having a high voltage pic up. check the distributor cap. are the points in there eroded away? a gap too large will cause to much of a loss ov voltage. = less volts for the plug. too little spark, not a proper burn, to much? would probably just burn out plugs.

how about air? to to hard. if you dont have a smoke machine to introduce smoke into the intake to find leaks, get a can of brake of carb clean. spray some joints in the hose to intake manifold, around the injectors, and such. if the idle increases, (may have to do it hot in your case) than there is unmetered air getting in. that would cause o2 to read lean, and richen the mixture. plugged air filter, dead bird ext, not enough air.

and finally fuel. and hers my hypothesis. besides this happened to me once. TOO MUCH FUEL!! have you pressure tested yet? probably plugged pressure regulator, or blocked return line. cold engine doesn't use o2 sensor. just the AFM. meter reads x amount of air, gives x amount of fuel. computer gives an injector pulse in milliseconds. this is "open loop" when it doesn't use the o2 sensor.

now if its getting too much fuel, the computer doesn't know. the fuel pump will put out about 90 psi. 3x the normal amount. so cold idle its going to get 3x the fuel.

that will make it run terrible, until the o2 kicks in. "closed loop". the o2 sensor tells the computer its running rich, and cuts the injector pulse, leaning it out, letting it run "better"

one more thing, you mentioned exhaust leak? is that before or after the 02 sensor? that can cause a rich symptom too. when the exhaust pulses go past, they will suck in oxygen and the sensor will read it as lean, and richen the mixture. causing poor fuel mileage. if leak is after o2 and before cat, it will actually assist in the catalyst proses. so dont worry about it.

[88formula]

- The #4 injector is different than the rest, it's green instead of orange, I also noticed a couple months back when I did my fuel lines that it had a bit of extra plastic at the point of injection which made it look different than the rest, I cut this off - could this be causing my problems? Did I dun mess up?

I'll begin reassembly now and see what happens...[/quote]

Did your one injector have that little "hat"? They all should. It helps to properly atomize the fuel. You should be able to get an injector kit that will have the caps and seals.