Idle Problem 1995 Jetta III

[boschmann]

Well, I guess it's on to fuel system. How old is the fuel filter? Do you have access to a basic fuel pressure gauge? Fuel pressure problems oftemn do not set codes either.

[Jetta III]

Originally Posted by boschmann

Well, I guess it's on to fuel system. How old is the fuel filter? Do you have access to a basic fuel pressure gauge? Fuel pressure problems oftemn do not set codes either.

Well, after checking my records, it seems the fuel filter was last replaced @ 105K. I am now @ 153K miles.

I specifically asked the last time the car was in the shop and they said it was okay. However, he didn't specifically answer my question when I asked about that. I thought maybe it was going bad too.

Probably worth replacing. I don't have a fuel pressure gauge, but could buy one if it's worth the money.

I was also thinking that I could of possible purged the codes by accident. I was reading one of your other posts about how NOT to jump the connection BEFORE you turn on the ignition. However, I feel I did it correctly prior to trying this and got the same results.

It's probably worth driving another week to see if I can generate the codes again if they were there. I'll check into the Fuel Filter.

I've heard that these are easy to replace, however, de-pressurizing the fuel system is advised before disconeccting it. I heard to do this, you remove the fuel pump fuse, and then you start the car to drain any pressure in the line, then you can replace the filter.

Please confirm if that is correct.

Thank you!

Jeff

[boschmann]

That will work to depressurize the fuel system. On your car it isn't as important as the eariler A1 & A2's which had the filter beside the battery. When you broke loose the fitting the wrench would head straight for the positive battery terminal. Spray of fuel + spark = unhappy customer. All you need for testing fuel pressure is a cheap basic gauge that goes at least to 50 psi & has a barbed fitting or rubber hose about 1/4" ID.

[Jetta III]

Originally Posted by boschmann

That will work to depressurize the fuel system. On your car it isn't as important as the eariler A1 & A2's which had the filter beside the battery. When you broke loose the fitting the wrench would head straight for the positive battery terminal. Spray of fuel + spark = unhappy customer. All you need for testing fuel pressure is a cheap basic gauge that goes at least to 50 psi & has a barbed fitting or rubber hose about 1/4" ID.

Okay, I had the fuel filter replaced today along with a Radiator flush. The care seemed to run cooler which helped keep the problem at bay. However, I still had a hint of the problem when I almost got home.

My mechanic (New one) thought that he would check the TPS next. Is this something I can clean to see if it makes a difference?

I'm also going to check on the fuel pressure as you advised. He didn't have time to do it today.

Jeff

[boschmann]

A bad TPS will keep the check engine light on all the time. They can get bad spots where they are only dead for a moment so no CEL comes on, but I've never seen one on a VW do this yet. Did you pull the distributor's electrical harness connector & clean apply an electrical contact grease to the pins?

[Jetta III]

Originally Posted by boschmann

A bad TPS will keep the check engine light on all the time. They can get bad spots where they are only dead for a moment so no CEL comes on, but I've never seen one on a VW do this yet. Did you pull the distributor's electrical harness connector & clean apply an electrical contact grease to the pins?

Okay, I bought some electrical connection cleaner, sprayed out the internal housing and the connector itself and then applied some contact grease.

We'll see how this works out. I also cleaned up the ground connections to the engine block, they were totally covered with oil & gunk.

What's next after this? Should I work my way up the wiring system to the big harness off the engine block? That's where this connects to correct?

Jeff

[boschmann]

I was only questioning the distributor connector as it is a common problem area, those wires go on to the ECM connector under the cowl, which is not a common problem area.

[seafeye]

I have a 1995 Jetta III, with the same problem.

This car has been a piece of crap the whole time i owned it.

All 4 windows and sunroof have broken.
A/C crapped out. (Expansion valve and evaporator)
A/C thermal switch/sensor needed to be replaced
Brakes are leaking at the left rear drum.
Handles like a lada.
Heated Seats do not work
Instrument lights are burnt out.
Door strips all fell off.
Lights on heater panel burnt out.
Key sticks in ignition.
Leaks coolent, at the head.
Exterior door handles are badly faded.
Rear window seal disolved to nothing....i live in florida
Alarm goes off whenever...

I use this car as a spare....who would ever buy it?

Keep the idea;s coming about the bucking problem, i will let you
know if i can sort it out myself.

I do not get any engine lights.
1995 does not have the OBDII computer.

[mlb81]

There is a sensor called the IDLE AIR CONTROL valve (IAC) and it is a small soda can looking guy bolted to the right side of the 2.0L intake manifold (when looking at the engine standing in front of car) with only on connector plugged into it. If that's going bad you'll experience jumpy idle - experience talking. Also check your water temp sensor. If it is crap or the wires burnt it will trick the ECU and mess with the idle circuit. Sounds like the IAC to me though. Hope it helps.

[GANYA]

how do i take out the radiator of a 1995 jetta vr6?