stuttering and boging on acceleration

[kemicala]

hi guys, i really need some help on this one. My car just started stuttering and bogging down really bad yesterday when im trying to accelerate. i used to notice a slight similar sensation usually when it was raining outside. almost like something was stuck in the intake and the car wasnt getting air. during those times i never thought much about it because it only seemed to happen when it was raining and it was never serious.
so when it happened again yesterday i pulled the air filter and found some tissue had go caught on the filter. i removed it tried to dust the filter off and went for a test drive. same problem. and it was bad. at times i could barely get the car going past 20. it would feel like the car wanted to shut off but it never did, it just didnt want to go.
i decided to go change the filter and also put some heet in the tank in case i had some bad gas. the symptoms where still there.

other symptoms ive noticed include:
when im doing a gradual light acceleration from a stop i can USUALLY get going up to highway speeds with out problems. there might be a slight hesitation around 30-45 mph.
if i go WOT from a stop i get a hesitation around the same 30-45 mph and the RPMs will drop.
if im going around 20mph and hit the gas the car will to accelerate but the the RPMs will start to drop then go up and drop again, over and over.

ive went and cleaned the MAF sensor today as well as the throttle body the best i could. both with there respective appropriate sprays. im not sure how well i cleaned the throttle body because i didnt take the screen off but i at least didnt do it with the MAF sensor still in place and i tried moving the throttle linkage to hopefully open the butterfly flaps. since i couldnt see in there im not sure if that helped. when i sprayed it down well, i turned the engine on and revved it a little to make sure as much fluid as possible was removed before putting the MAF sensor back in. i took it for a drive, going full throttle from stop and even mashing the pedal any where from 45-60 on the highway. it all felt good for about 10-15 mins now it seems the symptoms are back.

ive done a major tune up less than 12k miles ago. plugs, wires, fuel filter, pcv valve, transmission pan & filter.
only thing left i can think of is o2 sensors which i havent changed since getting the car at 97XXXk miles and i dont know when they were last changed.

of course, ive already searched and read some posts and many people point to plugs and wires, MAF sensor for what i believe to be similar symptoms. i was just hoping i could get some fresh opinions and ideas. i hope ive provided enough info and the post is easy enough to read, thanks.

[willwren]

95% of these problems will be ignition related. That being said, make sure your coolant level isn't dropping.

Pull all 6 plugs, keep them in order, and post a picture of them here. Don't mix them up. Facing the engine, left to right is 135 in the front, 246 in the rear (2 being below the alternator, 6 being closest to the driver).

[kemicala]

95% of these problems will be ignition related. That being said, make sure your coolant level isn't dropping.

Pull all 6 plugs, keep them in order, and post a picture of them here. Don't mix them up. Facing the engine, left to right is 135 in the front, 246 in the rear (2 being below the alternator, 6 being closest to the driver).

i havent had a chance to pull the plugs yet for pictures but i did notice that my coolant is slightly below the cold line when cold. what does this mean? intake manifold gasket faults?

ok so i pulled the plugs, and this is what i came up with. hope the pictures are good enough, it was hard trying to get a focus on them. i labeled them from left to right plug 1,2 and 3 on the front, and 5,6 on the back. i didnt pull 4 because it was just really hard to get to. and at the same time all the plugs look to be in the same condition.

[willwren]

I have a nasty taste in my mouth. Tell me what brand and type those plugs are? And what are they gapped at?

[kemicala]

I have a nasty taste in my mouth. Tell me what brand and type those plugs are? And what are they gapped at?

they are NGK TR55 with the factory gaps on them. i didnt change the gap when i got them.

[willwren]

Those are not V-power TR55's. Are they Irridium? If so, please check the gaps on them, they 'look' too big for a stock gap to me.

[renchjeep]

I am guessing clogged cat or exhaust?

Plugs may not be the preferred type, but look a bit lean.

Fuel pump maybe going south?

[kemicala]

Those are not V-power TR55's. Are they Irridium? If so, please check the gaps on them, they 'look' too big for a stock gap to me.

im not sure if they are irridium or not any more. i thought i saved at least one box when i bout the plugs just for future reference but i cant seem to find it now. im going to just go ahead and replace them with some ac delcos. what about the low coolant though? you mentioned that and i happen to have a low coolant level.

[00Beast]

Those gaps look HUGE! Replace them and the wires ASAP. I recommend NGK V-Power TR55 (copper core).

[kemicala]

I am guessing clogged cat or exhaust?

Plugs may not be the preferred type, but look a bit lean.

Fuel pump maybe going south?

im going to change out the plugs and wires. as well as the lower intake manifold gasket. but how does the cat or exhaust get clogged. how can i test for this.

also, for anyone knowledgeable about the fel-pro lower intake gasket, do i need to use any additional sealant when applying the gasket or do i just clean the surface (chemically i believe?) and lay the new gaskets on and replace the manifold?

[renchjeep]

Cat gets clogged over time, especially if there is a rich condition. This causes the cat temp to increase, which can melt the internals of the cat. Clogged exhaust can result from muffler damage, due to internal rust, accident damage, or internal collapse caused by backfiring.

I used to test for bad cats/clogged exhaust by hooking a vacuum gauge to a manifold vacuum source, and observing the readings on the gauge at idle and under WOT conditions.

My memory is a bit foggy here, as it has been a LONG TIME since I have even seen my vacuum gauge.

Maybe someone else can chime in?

OBD2 has erased almost all of my "old" mechanic knowledge.

[jonnevilleSSEi]

Forgive me for this off-topic but related reply. To take photos close up the important details include setting the camera to Macro and/or if required get far enough from the plugs (or other small detail) so the camera can focus on the subject and not the background. If there is a lot of extra background that can always be "cropped" off (removed) so that the subject of the photograph is most of the image. Any set of photo editing tools on a computer (iPhoto on Mac) can do this.

Now on cars (which I admittedly know much less about) I didn't notice mention of a check engine light. The forum can correct me but I suppose that would possibly eliminate some causes of this. When I experienced something like this most recently it was a cracked #6 plug, replaced it and it had been fine since until earlier this week when the check engine illuminated and a test indicated it was again #6. As the plug had previously been manually cracked while installing it I don't know why there is another problem with #6 but I reset the OBDII and we'll see. I guess the point is could be a single bad plug but if the symptoms are that bad I'm surprised it didn't toss a code.

[kemicala]

Forgive me for this off-topic but related reply. To take photos close up the important details include setting the camera to Macro and/or if required get far enough from the plugs (or other small detail) so the camera can focus on the subject and not the background. If there is a lot of extra background that can always be "cropped" off (removed) so that the subject of the photograph is most of the image. Any set of photo editing tools on a computer (iPhoto on Mac) can do this.

Now on cars (which I admittedly know much less about) I didn't notice mention of a check engine light. The forum can correct me but I suppose that would possibly eliminate some causes of this. When I experienced something like this most recently it was a cracked #6 plug, replaced it and it had been fine since until earlier this week when the check engine illuminated and a test indicated it was again #6. As the plug had previously been manually cracked while installing it I don't know why there is another problem with #6 but I reset the OBDII and we'll see. I guess the point is could be a single bad plug but if the symptoms are that bad I'm surprised it didn't toss a code.

sorry about the pictures, i looked but couldnt find a macro mode on my phone/camera. my dedicated camera was stolen. but i will keep in mind the cropping part. i definitely could have done that.
as far as the engine, there is no check engine light. ive also pulled all the plugs except #2 because its the hardest to get at. all the others seemed about the same, if i have a bad plug i hope its not the one i happened to not pull. but i am also able to pretty much side step the hesitation and stuttering while driving by just not driving the car with any sense of urgency especially between 30-45 mph. and also since topping off my coolant which was about 1 inch below cold last wed it is still right around the right markings. but i noticed it did drop a very little because i slightly overfilled it past the cold mark when it was cold. so i imagine this may very well be a failing lower intake manifold i have on my hands.

i went and bought the fel pro replacement, but before i start to work on it, i was wondering if anyone could tell me if i will need to replace any other gaskets when i remove parts. the FSM doesnt seem to indicate a gasket between the intake plenum and lower intake but ive found some very skinny gaskets online that seem to fit that application.

[Bing]

Go to techinfo section, Bill Buttermore did an excellent write up on the LIM and UIM gasket replacement for the 3800 series II. Should be able to answer all your questions there.

[Billha]

Perhaps I've missed something in this thread, but have you checked the coil packs with a multimeter?
In my experience, being able to accelerate ok when accelerating slowly, but bogging down while accelerating more quickly could be a symptom of an open coil pack.

[reb]

Have you taken off the EGR valve and checked that it is not sticking. I have to clean/lubricate the EGR valve piston every few years or my car will exhibit the symptoms you describe.

[kemicala]

Perhaps I've missed something in this thread, but have you checked the coil packs with a multimeter?
In my experience, being able to accelerate ok when accelerating slowly, but bogging down while accelerating more quickly could be a symptom of an open coil pack.

thanks for the input, i will take a look at the coil packs as well.

Have you taken off the EGR valve and checked that it is not sticking. I have to clean/lubricate the EGR valve piston every few years or my car will exhibit the symptoms you describe.

i have not done this but will look into. when u say youve had these symptoms, did you also loose a little coolant? just that part alone leads me to believe its the LIM as willwren hinted at.
thanks for all your suggestions.
oh and does anyone know the avg. cost for a LIM gasket repair? i looked at the suggested techinfo link and that looks way out of my scoop. it looks even more complicated than the factory service manual makes it look like...or even better, anyone around Maryland who has done the repair?

[willwren]

With this car still broken, I have to ask why we're throwing out all the ideas, and you haven't pulled codes yet? The digital EGR valve on a 93 would certainly throw a code if it was an issue. Your plugs have already been identified as a potential problem. Get a cheap set and throw them in if no codes show up.

Techinfo has the code-pulling procedure if you need it. All other suggestions should be taken with a grain of salt until you do these two things, and before you throw any more parts or money at the problem.

[myfirstbonnie]

[kemicala]

With this car still broken, I have to ask why we're throwing out all the ideas, and you haven't pulled codes yet? The digital EGR valve on a 93 would certainly throw a code if it was an issue. Your plugs have already been identified as a potential problem. Get a cheap set and throw them in if no codes show up.

Techinfo has the code-pulling procedure if you need it. All other suggestions should be taken with a grain of salt until you do these two things, and before you throw any more parts or money at the problem.

sorry for the delayed update. my check engine light finally came on on sunday while driving for about 10 seconds then went out again. i got a chance to pull the codes on monday and came up with these:
31,34,39,43,66.
ill check for codes again tomorrow to see if any come up that arent triggering the light.
...also when i changed my plugs, i checked the gaps and they were all alright, but i changed them anyways with some auto lites, all of which i checked the gaps again before installing. and concerning the coolant, i dont seem to have lost any since the last time it was low and topped off. that will be 3 weeks after tomorrow.