boghog

I have several issues with my 93 Astro that I need help with.

First, air only blows out of the defrost and floor vents when the selector is set to vent or bi-level AC. It appears that all the vacuum hoses are connected to the selector switch.

Second, on the passenger side of the throttle body, there is a device that I cannot positively identify; it's either the MAP sensor, Idle Air Control sensor, or Throttle Position sensor. It has two vaccum ports, but only one has a hose connected to it. It would seem that all I had to do was connect the hose, but it is not present so I don't know where it comes from.

Third, on the driver side of the engine just below the exhaust manifold near #5 cylinder is a sensor that I thought was the temperature sending unit, since the temperature gauge is not working, however, looking at the ECM sensor chart, it appears that this is either the Exhaust Oxygen sensor or the Electronic Spark Control sensor. The wire connected to this sensor has broken off.

Fourth, on the rear of the AC compressor there is an electronic connector that has no wire going to it, but the compressor kicks on. I'm assuming this is some kind of test port but I am not sure.

And last, when I first start the engine, there is a puff of white smoke. Thanks in advance for any solutions or suggestions.

Jasen

as far as your HVAC issue. The vac line is probably bad. I'm not exactly sure of the GenI, but the GenII used a plastic line to get the vac from the motor to the control unit. They get cooked and crack and or the connection fittings give out as well.
When my 97 did this I just got a piece of rubber vac line, cut the plastic line off a few inches from the fittings and slid it onto the fittings at either end, re routed the line away from the motor and problem solved.

ihatemybike

1) Just had that with Grumpy. Had a vacuum line in the engine compartment fall off.

2) Been a while since I've wrenched on an older van, but that might be what's causing #1

3) Can you provide a pic? Don't want to say it is anything without being sure.

4) Any loose wires nearby?

5) Most likely burning something you shouldn't be. What does it smell like? Does it smoke when you floor it? I had a 1994 that produced white smoke as it was burning oil.

russ75707

The ect sends temp info to dash gauge I believe,I too thought this was temp sending unit,I broke that and knock sensor working on van.It's hard to get your hand past that bracket that holds compressor up,and I think it's a 10 mm bolt,I only have 1/4 sockets that size and they WILL break....so I tried to work around,and broke more stuff.go figure. On the drivers side of 4.3 there are two sensors that screw into block,one (i believe)is a knock sensor,the other has one wire,temp sensor?