1.8 fi problems

[sking]

can anyone tell me what would cause my car to run like crap when it's cold but runs great after it warms up.i live in san diego so it's not too cold
thanks shawn

[Jim Smolka]

Could be a bunch of things.
1st check all the basics, (Mechanics, points, plugs etc)
Then the Aux air valve
Not sure if a 1.8 has cold start fuel valve

[tbil]

Like the previous post, it could be lots of things. When my 1.8 starts to act up like this the first check is always points, dwell and timing. Since your car runs well warm, these may not be the problem. I've found the cylinder head temp sensors don't last too long and that's an easy check. I believe you should have 2500 ohms with the engine cold.

You won't find too much info on the L-Jet, AFC, fuel injection systems that helps with problem solving. If you can locate an old VW bus shop manual from 74/75 it has a pretty good problem solving and dignostic section on the L-Jet.

Good Luck!

[Dave at Pelican Parts]

There are L-jet articles over on http://www.type2.com . They seem to be pretty good to me.

--DD

[sking]

do you think that the difference in the temperatures that are stamped on the thermo switch could cause this problem?the one i have says 35 degrees celcius and that is pretty hot.
thanks shawn

[Dave at Pelican Parts]

Which thermo-switch?

There is one in (or below?) the manifold in the 1.8, more correctly called the thermo-time switch. It controls the cold start valve, and will prevent it from operating above a certain temperature. I think the temperature is between 30F and 50F.

Note that the CSV can only open while the starter motor is cranking, and the TTS will only allow it to open if the temperature is below that value. The CSV should never be open when the engine is acctually running.

--DD

[sking]

it is the one that is below the manifold.the one that i took of because it was broken said 15 degree celcius and the one on it now is 35.when i got the engine i started taking it apart so i don't know how the engine ran with the other.i know that it controls the cold start valve .so does that mean that the problem is the cold start valve or the thermo switch,because the runs great after about 5 to 10 minutes of running.thanks for any info you can give me.
shawn

[sking]

the car starts up with no problems whether it's cold or not.it's just when i try to give it gas is when it boggs down.

[Dave at Pelican Parts]

The CSV does not operate unless the starter is cranking. So it is almost certainly not the problem. (If it were leaking, you'd probably have problems all the time.)

Start by checking the ignition system thorougly. Do a compression check while you have the plugs out to look at them. Verify that all your vacuum hoses are in good shape and are correctly routed. Make sure that the valves are ccorrectly adjusted.

Next suspect, to me, would be the head temp sensor. Check its resistance when cold and when the engine has warmed up. Should be ~3000 ohms when cold, <100 when warmed up.

--DD