Drive-ability Problems (surging, hesitating)...

[chryguy]

This may not be the right place to ask this, but I want to talk to the 3.0 experts.

I've had several 3.0's with the same or similar problems.
I've even had one car at the dealer, on the scanner, and talked to the most "3.0 knowledgeable" tech there (their 3.0 guy). No help...

These may be separate problems...but they seem to often be present together.

#1 is a hesitation that you can feel from a dead stop or even while the car is moving. Any time you apply throttle the car hesitates. Sometimes a lot, as in nearly dying, other times as a slight hesitation.

#2 is a surging. Sometimes as much a thousand rpm's, other times very slightly. Seems to do it at all throttle settings and even while the cruise is on.
Like I said, often accompanied by the hesitation, but not always.

I've checked vacuum lines, done a complete tune-up with Chryco parts, and thrown some parts at it on the suggestion of the dealer tech, like the temp sensor, and cleaning the TB. No cure.

Anybody experience this? If not, have any suggestions which direction to look?

Thanks in advance,
CG

[RoadWarrior222]

I get similar but not quite as pronounced behaviour when the fuel filter is due... and the quality of available filters seems to have tanked in the last 5 years, or gas has got crappier, because they now seem to be an almost yearly item instead of every 2 years or so.

Top PCV hose sucking flat can cause weird behaviour, examine it when it's cold, looks normal, then when its warm and pliable, flattens in vacuum, then you go look after you switch off and it might be almost normal shape again.

[Orangetona]

Sounds like it could be the EGR to me.

[Ondonti]

Fuel filter is something I would look into. 3.0 doesn't act like that when its happy.
I don't believe in such a thing as a dealer 3.0 tech.

There could be a lot of t hings wrong and he probably has no idea what to really look for. Our cars run fine with a bad CTS, just idle too high and run too rich (wasting lots of fuel). Someone who actually knew about the 3.0 would know that.

You could have a sketchy TPS or map sensor. You promise the car has no stored codes?

[c2xejk]

Auto or Manual? What year and model? Is it stock or do you have mods? Do you notice it in the cold or heat?

[chryguy]

Thanks a bunch for the responses,

They have all been auto's. 89' which I still have. 91'which I have since sold. 94 which has just started displaying symptoms. . They are(were) all stock.
The 89 Dynasty displays it constantly. After a timing belt and complete tune-up it was not as bad...but still annoying.

The long since gone 91 also displayed it constantly. The body on it was decrepit, so I didn't throw money at it.

The last one is the ex's convertible (94). Had been running adequately (not perfect, but not badly either). Previously I noted that it didn't have a strong idle, meaning when cold it would idle low and die 50% of the time if you reved it and just let it drop.
Once warmed-up it would idle fine. This one could probably use a tune-up, which I'll do now.

I haven't had a chance to see it from a cold start with the surging, as it just started a couple days ago. This one surges when running warm.

Hope that covers what you needed to know...

CG

[bakes]

Check to see if you have a lazy O2 senor with a volt meter if you dont have acess to a scanner.

[RoadWarrior222]

Worth a shot, mine got extremely fugged up and didn't throw a code... new one runs very smooth, but didn't get major driveability concerns with the old one, just sucked an mpg or two more.

[shadow88]

I wouldn't hesitate to swap tps's or a whole throttle body. I like the egr thoughts, and I think that may be a culprit too, but I would lean towards tps as well.

[turbovanman²]

I would hinge on a bad ox sensor, weak fuel pump, dirty injectors, carbon build up on the valves which absorbs the fuel, bad tune-up parts or if it has an EGR valve, a bad transducer. Easy to diagnose, just unplug the hose to the valve and plug it off, if the problems gone, get another valve from the dealer.

[RoadWarrior222]

dirty injectors, carbon build up on the valves which absorbs the fuel,.

Something of that sort happens after a month or so of only city driving, fixes with a cup of isopropyl alcohol in the tank and an Italian tune up, hit 5500rpm a few times.

[turbovanman²]

Something of that sort happens after a month or so of only city driving, fixes with a cup of isopropyl alcohol in the tank and an Italian tune up, hit 5500rpm a few times.

Depends, some GM's are bad, only taking it apart or walnut shells fix it. Others, you can use a high power commercial injector cleaner to clean it.

[RoadWarrior222]

Yarrr, the first time I realised it was happening after a good few months city crawling and it was running lumpy with a slight miss, (Only had it a year or so back then) everything else was eliminated, and it took 500ml varsol, 500ml isopropyl, a cup of ATF and beating the tar out of it for a week to clean it up. I guess the other is really just the maintenance dose.


Edit: Oh btw since we've had ethanol in the fuel, it's barely needed it, even with winter city crawling... one benefit I guess.

[Ondonti]

haven't even heard yet if you have any codes.

[RoadWarrior222]

I would be guessing that there ain't any... (This motor tends to piss me off in the number of things that can be "off" without it throwing any)

Just re-read OP and had half a memory jogged... I think this was the Voyager... few years back had a surging problem, very intermittent, seemed to do it when I hit a bump... had to drive with my foot wedged tight sideways to make sure it wasn't just my leg bouncing on the pedal... anyway this bugged the hell out of me for weeks... started figuring it was a bad contact somewhere, so unplugged and cleaned TPS, squirted contact cleaner in it, cleaned the body, motor and battery grounds and terminals... went away, didn't come back.

[Ondonti]

Lets remember it has nothing to do with the engine, its the Chrysler electronics controls that were crap in all their platfroms.
ODB1 also.

[TurboV6Van]

I had similar surging issues once. I changed the fuel filter, and used some stuff to take out the moisture from the gas in the tank. No issues since.

[chryguy]

I checked the convertible last night, no codes.
This one only hesitates/surges sometimes...didn't do it last night to speak of.

On a previous Dynasty I had I did a complete tune-up with MOPAR parts, a fuel filter, air filter, new scrub pad for the PCV, and a new temp sensor. I also took it in to the stealer and had a friend/tech put it on the DRB...couldn't find anything, couldn't make it stop.

That said, I bought a high-mileage Neon that had a weird surge off-throttle and coasting. Took off the throttle body and cleaned it. Cured it.

The convert will get a complete tune-up and TB cleaning in the next two weeks. I'll check back with an update then.

Thanks for the help,
CG