1971 Fuel injected type 3 Revs really high

[John Penner]

Hi There

I am now to this site and new to Volkswagon. I have a 1971 type 3 notchback Fuel Injected that has been sitting for 25 yrs with the engine out of it. I got the engine in, wired it as best i could following the wiring diagrams. I have 30 psi fuel pressure, have not checked the timing but the engine ran when it was removed and i didn't touch the distributor. The Issue I am having is, i get the car to start, it stutters and backfires at first and then will run rough for a few second and then quickly build up RPM's so I have to shut it off. Any suggestions as to what might be causing this to happen would be appreciated.

[KTPhil]

Assuming the gas pedal linkage is adjusted right, my next guess is that you have a leaky (or missing) hose to the Auxiliary Air Regulator (AAR), or the Manifold Pressure Sensor (MPS), and that extra air is acting like an open throttle, causing the engine to rev.

Manual or auto tranny?

Post some pics of the engine bay and we might find something.
_________________
Current Fleet:
- '71 Fastback
- '69 Westfalia
Retired:
- '67 Beetle
- '65 Beetle (x2)
- '65 Bus
- '71 Squareback

[John Penner]

I will post some photos shortly. It is automatic, the throttle linkage seems to be adjusted correctly. I had a friend put a different air filter onto it so we eliminated to oil bath one. We put less hoses onto it so maybe we missed something

[John Penner]

[raygreenwood]

[KTPhil]

If you still have it, I'd put the stock air filter back on the car. It filters better, has less restriction, and allows proper crankcase venting. It also won't draw hot air in, instead pulling from the fender passages like is done for for cooling air.

By the way, the bellows between the fan shroud and the body is missing, so you are pulling hot air in to try to cool the engine. No bueno!

As I posted, check hoses from the MPS and AAR to the IAD (plenum). You probably have a disconnected or split hose there. These same air leaks will also confuse your automatic transmission's shifting.
_________________
Current Fleet:
- '71 Fastback
- '69 Westfalia
Retired:
- '67 Beetle
- '65 Beetle (x2)
- '65 Bus
- '71 Squareback

[Bobnotch]

[John Penner]

Thank you for your help, I will put the original air filter back on and try to figure out where all the hoses go. I understand your point about sucking warm air into the engine. If someone has a proper venting diagram that would be a great help.

I do have new bellows for between the body and engine, just haven't put them on yet, thought i would see if it starts before I do anymore work to it.

I will check for voltage at the AAR red wire, this is all new to me so I am just trying to figure things out as I go.

I can't get the car to run for more then an minute now.

I will put the original filter back on and see what happens.

Thank you all for your help

[KTPhil]

This is for a late model, so it has more hoses than your '71, but it might help.

Yours will lack the pair to the air cleaner at 3 o'clock. You shouldn't have parts 10, 11, or 12, or any of the hoses shown connected to them. 13 is just one hose on yours. Also, your breather does not connect to the plenum (IAD); it connects to another nipple on your air cleaner.

Sorry, this is the closest diagram I could find.

Here is a photo of a '71 automatic engine; maybe this will help with some hose routing.

_________________
Current Fleet:
- '71 Fastback
- '69 Westfalia
Retired:
- '67 Beetle
- '65 Beetle (x2)
- '65 Bus
- '71 Squareback

[John Penner]

Thanks for your help everyone. I was missing the vacuum line from the pressure sensor, it still revved high after putting a new line on there. I moved the throttle by hand by the motor back and forth a few times, heard something click in the throttle body, now it starts and runs fine. I had been sitting outside for 20 years, something may have been a little stuck.

Problem solved.

Thank you for all your help !!!

[Bobnotch]

[John Penner]

I finally had some time to work on my type 3 tonight. It starts and runs fine, around 900 RPM when cold, as it warms up the engine begins to stutter and stall. If I start and try to drive it, shifting it into forward or reverse will make the engine stall... warmed up it was about 900 RPM. Once it stalls you have to give it gas to start it again, being fuel injected it should just start without giving it gas.

Fuel pressure is holding at 28 PSI when running.

new points, rotor and cap

timing hasn't been touched since it was put away... was running when put away 25 yrs ago

Any help would be great. Thank you