How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask gomi_otaku Your Own Question
gomi_otaku
gomi_otaku, VW Technician
Category: VW
Satisfied Customers: 3404
Experience:  VW FastTrack '00-'01, VW Academy Chicago and Seattle '00-present, VW Certified
12249065
Type Your VW Question Here...
gomi_otaku is online now
A new question is answered every 9 seconds

Volkswagen Vanagon Campmobile: I have an 85 vanagon that has

Customer Question

I have an 85 vanagon that has a hard time starting when cold. Usually starts up fine when it has been running, like after stopping for gas. Can't seem to nail down why?
Submitted: 1 year ago.
Category: VW
Customer: replied 1 year ago.
I've had a couple people say it seems as though it's only starting on two cylinders but once it warms us or is revved up the other two start kicking in.
Expert:  gomi_otaku replied 1 year ago.
Does it take an extended crank time to get started? It's possible your fuel tank check valve could be allowing fuel to drain back to the tank, and it takes a little cranking or some time of running until the pressure is back.If it's not that, but seems to be temperature related, it could be that your coolant temp sensor is bad and throwing off the fuel calculation- either enriching it so much that it floods ,or starving it out. You may also want to try tapping on your ECM box to see if that makes a difference, I have seen issues with the circuits on them that cause poor idle. Which, is also something that could cause an issue when cold, check and clean out your idle air motor at the intake.
Customer: replied 1 year ago.
Had new fuel pressure regulator and fuel filter installed. Also new air mass meter and air filter. Oxygen sensor and temp sensor both replaced as well
Expert:  gomi_otaku replied 1 year ago.
OK. Have you tried tapping on the ECM? I've seen them cause no start, poor idle, sudden stalling, etc.
Customer: replied 1 year ago.
Is the ECM the same as the ECU? If so, that is new/rebuilt too
Expert:  gomi_otaku replied 1 year ago.
I noticed you said new fuel pressure REGULATOR and FILTER- but if the tank is draining back, like I said, it will be starved for fuel on startup (there may be a small amount sitting in the lines but no real pressure)
Expert:  gomi_otaku replied 1 year ago.
I would check pump pressure on startup with a gauge in line
Customer: replied 1 year ago.
If I pull a hose off the air intake boot and spray starting fuel into the boot it helps it start up. It'll still run rough until it's warmed up but starts easier by doing this.
Expert:  gomi_otaku replied 1 year ago.
Like I said, I think the anti-backflow valve in your fuel pump is letting the fuel drain back, and it takes a bit to get it back up to full pressure. Replace the pump!
Customer: replied 1 year ago.
Talked to the mechanic and pressure was checked after all new parts were installed and everything was fine. He said that one side is missing and not firing at start up
Expert:  gomi_otaku replied 1 year ago.
Did he explain how that is possible? Has compression been checked, dry and wet? Is it possible you have injectors that leak down overnight, flooding the cylinder and washing down the walls, so they are not sealing well, and not getting fuel to boot?
Customer: replied 1 year ago.
Compression was checked. He said there is 50lbs crossing between cylinders so at start up compression was being shared between two cylinders on the drivers side. Above idle, 1500 rpm and up, the Pistons worked. Does this make sense?
Customer: replied 1 year ago.
You never responded to my last comment?
Expert:  gomi_otaku replied 1 year ago.
If that's the case, then it's likely the head is warped- any possibly they are able to seal after they heat up. The head would either need to be replaced (there are new parts still being made) or the surface planed so it is flat.

Related VW Questions