3.8L Hesitation

[fr8doggie]

I was referred here from another forum; told there were some good late model W-Body guru's here. Wondering if any y'all have an opinion on this little 'ole problem here.

 

Car is a '92 Regal w/ the 3800 & 4T60. 120,000 miles. About a month ago I would get slight engine hesitation at freeway speeds when going up a long, steep grade (Blue Ridge mountian area) almost like I was trying to accelerate in too low a gear w/ a manual tranny. Push the pedal down to get her to downshift, and all would be fine. Problem seemed to go away (more likely, I didn't drive in mountinous areas for a while)

 

This weekend, when moving to Charleston, WV, it not only started again, but has been getting worse; I can now detect the hesitation slightly under hard acceleration, and going up some steeper grades I have to downshift all the way to 2nd.

 

The plug wires are ~3 years old, and the plugs themselves have 8,000 miles on them. Replaced the fuel filter last August, and just ran a can of fuel injector cleaner through along with a 2/3 tank of premium (better detergents, right?) Car hasn't been using coolant, the air filter is clean, and I'm not getting a check engine light.

 

Tonight when I get home I'm planning on changing the plugs anway, along with the wires, if nothign else to take a look and see what the old ones look like. Right now I'm leaning towards a vaccuum leak somewhere in that mess of hoses under the hood, some of them look pretty cracked and rotted. With that, has anybody gone through and changed all/most of the vaccuum lines on one of these motors? There seems to be an awful mess of 'em, and I can easily see myself missing the one that is broken.

 

Any body else have any ideas? I really don't want to take it to a shop; I'm at work from 6am until 8pm M-Fr, so I'd most likely have to drop it there, and call them in the morning after they get in.

 

Thanks,

Mike

[JoroCorona]

I'd change those wires. If you had a vacuum leak, generally youd have a problemwith high idle aswell. However, if they look bad, may aswell change them, Vacuum hose is cheep.

 

This is a long shot, but check the tranny fluid. It should be nice and red. If its anything other then that, have the trans flushed and filled.

[19902drlumina]

i had a 3.8 1993 park avenue do the same thing put lots of money into it and never got it to run right i ended up buying a eng/trans w/low mileage to fix it. Probly not ure case though. and how are ur 02 sensors. good luck david

[99RegalGS]

How are the coils?

 

I think I know the problem you're describing because my old Regal did the same thing. It only does it when going up hills with the Torque Converter Clutch locked correct?

[Miko K]

I had the same problem not too long ago. The fix- at 1/4 tank add 2 bottles of ISO HEAT water remover and drive until empty, than fill up twice to get rid of the water/alcohol mix and done

[Slade901]

If your vehicle is ODBI, you can try to pull any codes just in case there is one. Typically, you just plug a jumper wire on A, B and you turn the ignition to ON (just before cranking). You will hear fan running and the check engine light should starts blinking the default code 12 which is..

 

blink, pause, blink, blink = 12

blink, pause, blink, blink = 12

blink, pause, blink, blink = 12

 

After that, then the error code will begin to flash. Once all error is displayed then it goes back to the default code 12.

 

However, I did have same problem with our vehicle hesitating. I put fuel injector cleaner and ISO Heet just like Miko_K said and it seems fine for a while and then lately, it started to hesitate again. This time the battery light flickered for a second (twice) and disappeared. Check engine light came on and disappeared. ABS light came on and disappeared. While this light came on, the engine/transmission hesitated.

 

I immediately suspected the alternator. Brought it to Autozone have them tested the battery and alternator. Just to let you know that you don't have to remove your alternator to have it tested. I knew that they can test your alternator in car but a long time ago some lazy autozone employee told me to remove the alternator before they can even test it. Well anyway, they tested my alternator/battery yesterday and sure enough the alternator was not putting the required amps and it's failing. So I got an alternator yesterday for 130a $149 + $40(core) LLT and I installed it and seems well for now.

 

Since, this sounds like tranny issues, when was the last time the tranny fluid replaced and tranny filter replaced? It may be time to replace it.

[maybe2fast]

my bet is the coils. or wires. and maybe try some seafoam

[fr8doggie]

Thanks all for the suggestions. Got home last night and it was raining at 35 outside, so went to the bar instead of changing the plugs & wires (knew I should have done that sunday when it was nice out!)

 

The trans fluid has about 30k on it, with a fresh filter at the change. It's still red and doesn't smell burnt. As someone else asked, it initially only did it with the TCC locked in, though now it's been hesitating and running kind of rough in 3rd and 2nd.

 

I've put only 40 miles on it since the last fillup w/ 2/3 tank of premium along with chevron fuel injector cleaner. At the same time I ran seafoam through the engine. If it's dirty injectors, it should take at least a half a tank I know to clean 'em out.

 

Alternator is good; puts out good volts at idle w/ most accessories on (I love having a full gauge cluster) and the battery is 3 months old. Coil packs were my other thought as well; as far as I know they're the originals.

 

It SEEMS today to be running a little better; or it could just be my imagination. Think I'll try the plugs and wires tonight, at the very least it'll let me take a peek at the condition of the plugs themselves and see how it's running.

 

Thanks for all the suggestions, I'll be sure to let y'all know if/when I get this bugger pinpointed.

[maybe2fast]

my bet is the coils. or wires. and maybe try some seafoam

[DiscoStudd]

I second the coils taking a shit. The coilpacks and the ICM (the "Ignition" module that sits underneath the coil packs) have a tendency to burn out due to the tremendous heat generated under the hood. The crank sensor on the 3800 is in a poor location as well, and will fail eventually. Also you might want to check the wiring to the crank sensor for any cracks or fraying.

[fr8doggie]

Well, the crank sensor was replaced last December because my dumbass ignored a leaky o-ring on that standpipe for the heater hose that comes right off the block above the water pump...

 

Is there a good way to test the coil packs short of throwing parts at it? I've got the magnavox ones, with the 3 seperate packs instead of one unit (either good or bad, depending on how you look at it)

 

The one nice thing about my schedual here; I have plenty of time during the day to think about all this stuff and research it, that's for sure.

[fr8doggie]

Well, finally got around to working on it Thrusday night after work. Was going to do the plugs and wires, but it was starting to rain, so I figured I'd try just the wires first; they were about 3-4 years old, the plugs were only 9 months old.

 

Well, the old wires were in sorry shape; insulators were brittle and heat damaged. The rubber was cracking and coming apart as I removed them. Put new ones on, and BAM; problem solved. No more hesitation, not even up real steep hills in OD. Went and drove up to my buddy's place in Jersey for the weekend; ~1000 miles round trip, ran like a champ.

 

Thanks for all the suggestions and friendly advice.