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Discussion Starter #1
Hey Gang,

I need some help. My wife's car is a 95 Voyager /w 3L mit. engine in it and about 215,000 mile on the van. Back in Aug. I had a local shop put a timing belt, water pump and new cam and crank seals on. I would have done the job, but it had been too hot and too wet, as I have to work in the drive way.

Got the van back, and it ran great, no oil leaks plenty of pickup, etc.

A couple of weeks later my wife said it was surging and stalling when she stopped at a traffic light or stop sign. It will refire right away, not problems.

No problem I said, I just need to clean the throttle body. So I pulled the throttle body and the idle speed controler, and cleaned with throttle body cleaner. But that didn't change a thing. Still surging and stalling.

So now for a little more info:

1. The fuel filter has less than 8K mi. on it.

2. I drove it to a buddy's last weekend to work on it. When I stopped, I put my left foot on the brake, and gave it just a touch more throttle, and the surging stopped.

My wife usually puts it in neutral at the lights.

3. When we were working on it, I didn't like the idea of it being in gear, even with the wheels chocked and the emergency brake set. I was affraid that a wild surge might have the van drive into my buddy's garage. So I turned on the headlight (high beam), the heater blower motor, and the AC. This load would cause the engine to surge, but it didn't stall that often.

We could find anthing obviously wrong. The TPS had a steady .7V output. We pulled the TPS and slowly swept it through it's full range, and the resistance seemed to increase smoothly as we went. The throttle body was clean. The Idle Speed Controler was working fine. But if you put your finger of the port in the throttle body, it would idle down to about 500rpm (base idle), but still surge. The EGR
seemed to be working correctly.

The only thing we noticed was the purge valve was cycling constantly. Don't know if that is normal.
Never really noticed it before. So we replaced the rubber hose that connects the purge valve to the
manifold. No change.

We cleaned the both connections to the battery and the ground where it attaches to the block (battery side of the front head,) and to the chassis (below the PCM).

I get no codes, except those that I have induced by pulling the connector for the evap system and the TPS. Disconnected the battery, those codes went away, and never reappeared.

I can start just throwing parts at this, but before I do, anyone have any sound ideas of what else to check or try?

TIA

John
 

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Sounds like it could be the EGR since it only happens at idle. The symptoms tend to match a faulty EGR. That would be my first guess. Perhaps the EGR valve is not seating properly at idle or the transducer is bad. Any chance you have a self serve yard that you could pull one from to try?
 

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Discussion Starter #3
John,

Thanks for the input. I've got a new TPS and EGR gasket. I plan on pulling the EGR and checking its seat, this weekend. I'll try a mity vac also to be sure that the EGR is hold an applied vac. and opening and closing appropriately.

Will report back after I play with it.

Anyone else have any ideas?

John
 

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Discussion Starter #4
John,

I replaced the TSP because it could have been a problem and was cheap, about $25. I pulled the EGR, and cleaned it. It appears to be working, when a vacuum was applied to the control vac. motor, its rod moved, and held vac. until I released it. I cleaned the passages with throttle body cleaner and reinstalled.

No change.

When the car is in Neutral or park, with the headlights on high, fan motor on hi, and AC compressor engaged, it will surge. When in Drive or Reverse, at a stop, it will surge and stall.

So now I have 2 options I think.

Replace the MAP sensor - even thought no codes - again an inexpensive part - about $30.

Replace the EGR just on general principals - a more expensive part.

Wondering what you suggest - the EGR since that's what you suggested previously? What kind of tests can I run on the EGR to prove if that is the problem?

One last question, can the timing do this? I had the timing belt replaced about 3 mo. ago. The problem started after that. I put a timing light on it, and had to adjust the timing on the light to about 30 deg. which seemed pretty far off. So we put the engine at TDC on #1 and then looked at the timing marks for the cams. The front cam was off by over 1 tooth.

So I'm trying to decide whether to pull it down like I'm replacing the timing belt to really check the timing or just shot gun the EGR?

As always, you insight is fantastic and I look forward to your wisdom.


John
 

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Even though you pulled the EGR and cleaned it and it holds vacuum, that doesn't mean that the transducer isn't faulty. I had an EGR that worked great on my Spirit. The problem was that the transducer was faulty. And you can't buy them separately, they come as a unit. I replaced them and that took care of my problem. Like John said, if there is a junk yard near you, grab a transducer and replace it. I don't recommend just buying a new one as they're kind of pricey and that may not be the problem.
 

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John,

I replaced the TSP because it could have been a problem and was cheap, about $25. I pulled the EGR, and cleaned it. It appears to be working, when a vacuum was applied to the control vac. motor, its rod moved, and held vac. until I released it. I cleaned the passages with throttle body cleaner and reinstalled.

No change.

When the car is in Neutral or park, with the headlights on high, fan motor on hi, and AC compressor engaged, it will surge. When in Drive or Reverse, at a stop, it will surge and stall.

So now I have 2 options I think.

Replace the MAP sensor - even thought no codes - again an inexpensive part - about $30.

Replace the EGR just on general principals - a more expensive part.

Wondering what you suggest - the EGR since that's what you suggested previously? What kind of tests can I run on the EGR to prove if that is the problem?

As always, you insight is fantastic. Look forward to a reply.


John
John, It starts to become a guessing game when you have no codes, but I recall an old service bulletin (non-Chrysler) that mentioned an occasional problem with the the Hall-Effect speed/distant sensor shorting out and pulling down one of the voltage sources from the PCM. By pulling down, I mean lowering the voltage or shorting out the signal line which is shared between sensors. From your description, it almost sounds like a voltage related problem.

Check the wires to your speed/distance sensor on the passenger side transaxle extension (it's on the top of the axle housing). If you see no rubbing through of the wire insulation, try disconnecting the sensor and see if it continues to surge. I'd give it a 30% chance, but I actually had this happen on my 96. It did throw a code and the speedometer flickered around a bit. Have you noticed any flicker from the speedometer?

The other thing I would do before replacing parts is to spray each connector with a good tuner/contact cleaner after inspecting each for corrosion or graying. Cycle the connector in and out to sweep clean the contacts. This would apply to the PCM too, but the PCM connectors should have grease on the base of each pin to help prevent moisture from getting on the contacts.

Edit: Your vehicle must have a 3 speed tranny for the above (speed/distance sensor) to be applicable.
 

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Discussion Starter #7
John,

No, I have the 4 sp xmission on this van. I had the 3sp on my 89 voyager.

Thanks again for the info. I'll look at pulling all the connectors apart and hitting them with contact cleaner. I
think I have a can of that around here someplace.

Then I'll put a dab of dielectric paste on the connectors when I put them back together.

John
 

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Discussion Starter #8
Could this be a timing issue?


When a timing belt is put on, I usually set the engine to TDC #1 before I start the job. The cam and crank marks are lined up correctly. But when I check now, the cam marks don't line up with the mark on the back panel behind the cam gear - at least the front one.

I really don't want to spend the 6hr ish to tear the covers off the front of the engine, but I'm thinking it may be
worth it.

John
 
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