F.I. To Carb Conversion for Vanagon

[Bob Ingman]

In my opinion , of all possible EFI problems a faulty cylinder head temp sensor is by far the easiest to detect. If your car will start cold and run a mile before dying then run again when cooled its time to change temp sensors. A little plug with a long fuse. The other components require some skill or equipment to diagose properly. Bob

[Piledriver]

I'm not certain, but the wasser doesn't have one in the head.

Temp sensor ...2? controls the warm up.

Both are on the tstat housing on the 88. Easy to check with a meter.

On the AC one you are absolutely correct.

[raygreenwood]

On the subject of troubleshooting Fi....its a cinch. In D-jet...there are 23 wires. In L-jet....it varies...but about 36. 6 sensors at most. The brain...never fails. Just put the VOM and fuel pressure gauge in the glove box along with your your wiring diagram...and scrawl the sensor and wire values on the back. Its about 30-40 minutes to check the whole system. Vacuum leaks...can be trouble shot by keeping your hoses and boots updated and troubleshot on the road by simply snipping the ends off and reclamping them. Fuel leaks are obvious. Ray

[alsehendo]

Go for / check the cold start valve on the front of penum like the one guy said. This is what happend to me in 2 L-jets with this exact sympton.

To test the auxiliary air valve, remove the 2 hoses from the valve and use a mirror and light source to look through the valve. It should be partially open when the engine is cold and fully closed when the engine is warmed up.

To check the entire system for air leaks, disconnect one hose from the auxiliary air valve and blow compressed air through the hose with the throttle open. Soapy water on hoses and connections will then indicate leaks. (http://manuals.type4.org/ljet/components/ljet10.htm)--I use it all the time.

I bought whole T4 engine from 80 Vanagon at bone yard for $100 just to cart off extra FI parts they were all good.

My Vanagon starts -10F or colder will you carbs--not?

[wildthings]

Most air polution devices including fuel injection have actually had positive affects on performance, milage, and longevity. Take the lowly PCV valve. It reduces emisions by 20 % on a new, well tuned engine and far more on an older one. It cost little and needs only very occasional maintenance, yet it effectively doubled or tripled engine life by removing water and acids from the oil, while at the same time doubling the oil change interval, further lowering your cost. It also made the roads much safer for high speed travel by eliminating that oily strip that ran down the center of each lane up through the early 70s.

Also take the intake air preheat stoves and heat risers for example. Heat stoves made carburated engines far more drivable when cold and increased gas milage by 10-30% yet were universally hated by dumb mechanics because they made it slightly more difficult to access the carb. Yet if one kept his dirt paws off the carb to start with, cleaner lead free gas made accessing the carb on a regular basis all but unnecessary. Ive made tons of money over the years by reinstalling preheat stoves on engines where they had been removed and removing headers pipes that had made engines undrivable because they eliminated the heat riser valve. This has been espesially true with VWs.

Its easy for the ignorant and uninformed to gripe about environmentalist, but I dont see many of the gripers moving to Mexico so that they can enjoy the benifits of the air polution and backwards technologies they so long for.

[raygreenwood]

Great points. Excellent post! ...but just remember, for the record...fuel injection is NOT an emmissions device. It just so hapens that cleaner emmissions are a by-product of better mixture homogenization and control. But.....so is horsepower and torque. Thats was the primary reason fuel injection was originally invented...long before anyone cared about emmissions. Ray