Idle Problem 1995 Jetta III

Hello Everyone,

I have a 1995 Jetta III w/ Manual Transmission. 150K miles.

Thankfully, until now I haven't had any major problems.

Over the past year, I noticed after about 1 hour or so of stop and go traffic, my car would start to buck, as if it had a compression or vacume problem. I was right, and they fixed my vacum hoses and life was good or I thought so.

A few weeks after that fix, I took it back in for the same problem & an oil leek. So, they put in a new manifold gasket, new Valve cover gasket, and a new cam shaft Seal for the compression problem?

They also replaced the distributor cap & rotor.

The oil leek is fixed, but after about 1/2 hour now in stop and go traffic, the bucking continues. I originally thought I had a transmission problem, so I replaced the clutch. That wasn't it!

The problem occurs hot or cold, and is not consistant in terms of when. Some days it happens, other days it does not. At any rate, when it does occurr, idle fluctuates from 1K to almost dying and bounces back and forth. It will die if I don't give it gas. It happens anywhere.

They gave me some valve cleaner and I am on my last tank, but the problem crept up yesterday and hasn't really gotten any better.

It seems like it's out of sync, or one of the cylinders isn't firing.

THere are NO codes they came up with in terms of the problem @ the Dealership.

I've yet to change out the spark plugs, but wouldn't that be a consistant problem?

I'm lost in terms of where to go next & would love any advice regarding this.

Hopefully I have provided you enough information, if not, then let me know.

Thanks,

Jeff

Update: I finally spent around $3,000 over a few months on trying to isolate and fix the problem. I gave up and purchased a new car. The only thing I didn't do was have the Injectors cleaned which was my next step. However, after plenty of bottles of injector cleaner, I didn't want to spend any more money trying to fix what was becoming an expensive car. In hindsight I should of used that money towards the new one. I should have also gone to a smaller mechanic which would have been cheaper than the dealership and probably a bit more straightforward regarding the problems I was facing.

Ironically, I experienced a similar problem with my new 2005 A4 when I blew an ignition coil and lost 1 of the cylinders coming home from a family trip. I did replace my ignition coil in the VW but that didn't fix the problem.

Good luck to everyone reading this.

You can try spraying the ignition coil (and even the plug wires & distributor) with water to see if it arcs. Use a fine mist from a hose or a spray bottle, you can do it at night for better visibility. If the coil is bad you will notice the symptoms get much worse.

You can try spraying the ignition coil (and even the plug wires & distributor) with water to see if it arcs. Use a fine mist from a hose or a spray bottle, you can do it at night for better visibility. If the coil is bad you will notice the symptoms get much worse.

Okay, I tried that, but no sparks. The problem often happens on a sunny day when water isn't present. Would that make a difference? (Actually probably not, if the coil is cracked then it probably wouldn't matter). In hindsight, I didn't soak the thing. I just misted the parts that were visible.

It's always when they car is cold, or when it's been running in traffic for 30-45 minutes. At that time, the idle seems to suffer and I get the bucking when in gear because the engine is lagging, or one of the cylinders isn't in sync.

I have a new cap/rotor as of March 04. What do you think I should try next? Do you think it is the oxygen sensor or hall sender?

Thank you for your prompt reply. I really appreciate it.

Jeff

a.k.a. Jetta III

I'd still look a little more at the ignition system. You don't have to be afraid to soak the components, they are designed to be weatherproof. Did you try driving it when it was wet, it's more likely to sputter under load. Are the plug wires original, if so I'd replace them. O2 or hall sender should set codes.

Okay, I bought new spark plug wires and new spark plugs. Is there any tricks to get them off?

I tried removing the wire from the ignition coil and it doesn't want to come off.

Is there a special tool needed to do this?

Let me know and thanks for your help.

No special tools are needed. They may get damaged when removed, but you're replacing them anyway. I find it easier to remove the plenum to get to #2 & #3 plugs, but it can be done with it in place.

Okay, I don't know what I was all worried about. Replacing the Spark Plug Wires was a snap. The wire harness was probably the harded part of this.

Upon removal of the old spark plugs, I noticed that the 2nd Cyclinder spark plug was almost TOO easy to remove. I dont' think it was properly seated.

Everything worked out wonderfully except I did manage to break off a bit of the plastic protector on the Iginition Unit when I removed that wire. I cut off some of the old rubber on one of the old distributor wire ends and used that to cover the gap.

I'll see how it works on a rainy day! Otherwise, I'll have to figure out what to do.

I noticed some pretty significant corrosion on the spark plug wires....Hopefully this was it.

I'll drive it a week and let you know. Thank you so much for your assistance.

Mission accomplished!

No special tools are needed. They may get damaged when removed, but you're replacing them anyway. I find it easier to remove the plenum to get to #2 & #3 plugs, but it can be done with it in place.

Okay, the bouncing idle problem when cold didn't happen today, however, after about 35 minutes on the commute home, the sputtering started again, causing the car to buck in any gear. When in Neutral, the car sputtered when I gave it gas.

I may have had several problems occurring, at least now, it's only happening when the car is HOT. I do have an exhaust leak or a hole in my exhaust pipe, do you think that could cause the bucking/sputtering?

Let me know what to try next. The problem seems heat induced. MAF? or should I still focus on the ignition coil?

I checked all the vacum lines and had the majority of them replaced within the last 2 months. I also had a new camshaft seal installed.

Let me know.

Jeff

Have you checked for codes again lately?

Have you checked for codes again lately?


I think I've read from this forum that you can go to Shucks or Autozone and they'll help you out. Is that true? Can I go anywhere?

Thanks for your help.

Jeff

I know from experience AutoZone will check and clear codes for vehicles with an ODBII system and interface. As for pre ODBII, I wouldn't be too hopeful for help at AutoZone. I am not sure what system the '95 had, but I think it might be pre-ODBII. boschmann is very knowledgeable and could probably answer that question and/or provide alternatives.

You would have to use a VW scanner or simulator like VAG-COM, OBD-II readers will not work. I'm unsure if Snap-on's system will work, most companies don't have the VW specific software. On several posts I have described how to retrieve the codes on pre '96 VW's yourself using a flash code method which has had varying success. Be sure to follow this carefully as you don't want to cross the wrong pins as damage will occur. The diagnostic link is beside the ashtray. Pull the tray and slide the cover left. The connector is two rows of eight pins. You will want to connect a jumper wire, such as a paperclip between two of them. The pins you are interested in are #4 and #15 (top row 4th from left & bottom row 2nd from right). First turn ignition to on, then connect jumper. The engine light will flash once then start a sequence of four digit codes with a short pause between digits & a longer pause between codes. Code 4444 is end of codes/no codes. Turn off the ignition to end. Post anything you get. Of course this is only basic information, a scanner would give much more detail.

OBDII DOES work on my 97 vw jetta 4cly 2.0
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OBDII DOES work on my 97 vw jetta 4cly 2.0L.. I have used the GENERIC OBDII and even the Snap on scanner with the wheel
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You would have to use a VW scanner or simulator like VAG-COM, OBD-II readers will not work. I'm unsure if Snap-on's system will work, most companies don't have the VW specific software. On several posts I have described how to retrieve the codes on pre '96 VW's yourself using a flash code method which has had varying success. Be sure to follow this carefully as you don't want to cross the wrong pins as damage will occur. The diagnostic link is beside the ashtray. Pull the tray and slide the cover left. The connector is two rows of eight pins. You will want to connect a jumper wire, such as a paperclip between two of them. The pins you are interested in are #4 and #15 (top row 4th from left & bottom row 2nd from right). First turn ignition to on, then connect jumper. The engine light will flash once then start a sequence of four digit codes with a short pause between digits & a longer pause between codes. Code 4444 is end of codes/no codes. Turn off the ignition to end. Post anything you get. Of course this is only basic information, a scanner would give much more detail.

Okay, I did what you said, and all I got was the Check Ignition Light staying on and it went off when I removed the jumper. There were no codes.

Did I do this correctly?

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, 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

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.

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

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?

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

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.

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.

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.

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