2000 GAGT Idling Rough, Hesitant Acceleration after tune up. [Archive] - GrandAmGT.com Forum

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eBandit
11-18-2009, 11:04 AM
2000 Grand Am GT 3.4L

To start off I have had intermittent SES light that go away and the car would only sometimes have a problem and not always when the light was on. Sometimes when I would be on the highway or going up and hill or passing someone, when I started to accelerate the car would hold back as if something was trying to actually hold onto the car from going.

It would then all at once take off and go! If while it was doing this, I let most the way off the gas pedal it would actually speed up just a tiny bit as compared to having the pedal down 1/2 way or more. Recently it got much worse and rather than occasional it did it for a much longer time. The it was OK the next day somewhat and only did it once.

I went ahead and did a tune up the other day and put new Autolite Platinum Plugs, Bosch Premium Wires and new Accel DIS coil packs (two of the old coil packs were corroded very bad on the plug ends and the Accel has brass ends so I went with those, they are new ones that were warrantied by accel from older ones I had).

After doing this as soon as I started the car and SES light was on and it was idling rough and almost seemed like it was missing. When I pull out it hesitates and then jerks and goes. It runs best when you rev it up not in gear, but in gear running or idle it doesn't run right. The SES light went out the other day but it still runs like crap.

Next I am about to go see what SES codes were set and if any freeze frame data is stored. I can also do live sensor data and enhanced data (among other stuff), but don't know what value that will be yet as i have yet to ever do that with a scanner. I have a INNOVA 3160 scanner that I ordered not too long ago.

I was also going to start it and unplug one wire at a time to see if anything changes and if not maybe change one coil at a time with the old ones. Even if this solve the issue of it getting worse I still have ti solve the original issue.

I'll update as I check stuff, but wanted to see if anyone had any ideas or had similar situation occur and can offer advice if I am on the right track in checking stuff.

thanks to anyone who replies- for the help.

GrandAmMe
11-18-2009, 01:19 PM
What plugs are you running?

K WeRd
11-18-2009, 01:43 PM
...new Autolite Platinum Plugs...

What plugs are you running?

:applause:

eBandit
11-18-2009, 02:20 PM
Update, the codes set (which probably were set before this new issue and might have something to do with the hesitant holding back it was doing before the tuneup) are as follows.

I also would want to ask, could the problem that was going on got worse for any reason after the tun-up? Or could the parts be faulty? Like the car started running worse because it has good spark now and it amplified the issue?

Code 1 (Priority code):

Manufacturer Specific Code:
P1404
EGR Valve Stuck Open or Circuit Performance

Freeze Frame data for this code:

Fuel Sys 1 CL
Calc LOAD (%) 4.3
ECT (F) 195
STFT B1 (%) 1.5
LTFT B1 (%) -10.1
MAP (inHg) 8.8
Eng RPM 1297
Veh Speed (mph) 39
MAF (lb/min) 0.854
TPS (%) 1.5


Generic Code- P0101
Mass or Volume Air Flow Circuit Range/Performance


Enhanced DTC code- P1189
Engine Oil Pressure Switch Circuit

Also shows code U1040
but the scanner says it doesn't have a definition for it and to see www.CanOBD2.com (http://www.CanOBD2.com) to find out which I'm about to do.

Also wanted to mention the car had a K%N filter on it but was dirty and I didn't have any oil (rather have other filter brands out there anyway) so I removed it and stuck a stock paper filter in when I did the tune up.

I just went out and was going to pull one wire off at a time to see if anything changes but when I pulled one off the spark jumped out of the wire into my hand. So I took the bulb out of a spark tester and insulated the end of it and put it inline one at a time right off the coil packs and it was hard to tell because I had to restart the car each time and if any of the plugs/wires had no change it would have to be number 6, but I'm not sure cause it was hard to tell. next I am going to try one or a couple of the old coil packs to see if that changes anything.



Thanks.

AaronGTR
11-18-2009, 04:50 PM
U1040 is for loss of communication with the electronic brake control module (EBCM).


Sometimes if the engine rpm goes up and down and it gets really low like 400-500 rpm and wants to stall, it will set codes like the 1189 engine oil pressure and possibly it could set the p0101 for the MAF too. Other wise, if there is an actual problem with the MAF that could certainly make it run bad. If your old air filter was dirty, the MAF might be too. Have you ever cleaned it? Give that a try, there is a write up in the "how-to" section. The EGR code could also be caused by a dirty stuck EGR pintle from carbon build up, or the solenoid itself could be bad, and that could cause it to run bad and hesitate as well. Try taking the EGR valve off and spraying some carb cleaner in both holes several times to clean out the carbon and blowing it out with compressed air. Hopefully that will free up the valve if it is stuck, otherwise you may need a new EGR.

Give those things a try and see if any of the codes come back. Other than that, only thing I would do is get rid of those autolite platinum plugs, they suck! People have all kinds of misfire problems with them and I'd bet that's why your car is running worse now. Get some Delco or NGK iridiums. And don't try pulling your plug wires off while the car is running! I can tell you what will happen right away. You're gonna get a misfire cause you have no spark to that cylinder but your engine is still running and the fuel injector is still firing... and you'll be dumping gas into your exhaust which will screw with your fuel trims and mess up the fueling to the other cylinders and make it run bad. And misfires/excess fuel will burn up your O2 sensor and catalytic converter if left too long.

eBandit
11-18-2009, 06:17 PM
thanks for all the info, I'll check it out.

eBandit
11-19-2009, 09:18 PM
Are the Autolite plugs no good for any vehicle then? I have put them in others before with no issues. But wont ever get them again if they are problematic in any vehicle.

GrandAmMe
11-19-2009, 09:35 PM
Well i heard some plugs cause major problem for our Engines. If you got the time i would throw the old ones back in and see if it runs better. Apparently the wrong plugs cause major problems for our Engines. Most people replace old plugs with the same brand plugs they took out (Ac delco?) (Someone verify the name).

eBandit
11-19-2009, 09:59 PM
well my old ones ac delco but real old and probable not in very good condition I would say.

GrandAmMe
11-19-2009, 10:04 PM
From what I have heard from other people on this site is that the only plugs that should go back in are AC Delco (correct me if im wrong)

eBandit
11-20-2009, 09:50 AM
whats the difference between a c delco and the slightly cheaper a c delco radpifire?

edit* I think the rapidfire plugs are only platinum on one end and the reg. ones are double platinum?

eBandit
11-20-2009, 12:58 PM
I cleaned up the old A/C Delco pugs which I don't know how many miles are on, but quite a bit I would guess and....

The problem got worse, the car runs much rougher than it did with the Autolite plugs and on the way back testing it, the SES light was flashing rather than being solid. When I stopped I briefly could smell something from the tailpipe not sure what though. It set code P0300 as the new Priority code which is Random Misfire Detected.

I'm about to put the old coil packs on and see what that does.

edit* Well at least I'm back to square one where I started now. Now I only have the original problem where the car holds back and doesn't want to go as well as the uneven idle where it drops all the way down to about 400-500 RPM and back up again.

So the car runs worse with Accel DIS coil packs and Autolite platinum plugs and runs even worse than that with Accel Coil packs and the old A/C Delco plugs.

So I wonder would it run OK with those coil packs and new A/C Delco or would it maybe be OK with the Autolites and the old packs? I don't plan on keeping this car too much longer anyway, but want it to last until I find the right deal on the right car to buy (looking for light wrecks to fix up, just like this one originally was). The coil packs were new directly from Accel, could they be bad. I guess I could have changed one at a time to see if it was just one pack bad or a deeper issue.

GrandAmMe
11-20-2009, 03:03 PM
Now i wonder if it is the coil packs...or maybe one of the sparkplug wires were put back on the wrong cylinder.

eBandit
11-20-2009, 03:09 PM
Now i wonder if it is the coil packs...or maybe one of the sparkplug wires were put back on the wrong cylinder.

100% not plug wires on wrong cylinder- they are in the same spot now as they were when the issue got worse. I marked the coil packs with marker, then marked the plug wires (new and old) with marker at ends and numbered tape on the wires. Made a diagram of everything all before taking it apart. changing the plugs back and coil packs back was done one plug and pack at a time so the wires never changed when it got better.

the Accel dis packs work fine normally on our cars, right?

AaronGTR
11-20-2009, 05:01 PM
Yeah, when the MIL light flashes (check engine light) that means there is a major problem, such as a really bad misfire. You probably smelled raw fuel getting burnt up in the cat coming out of your exhaust. They make it like that from the factory with the light flashing like that as a warning to let you know you are damaging your emissions equipment.

Accel coil packs should work fine in your car, but they are no better than stock ones. You should definitely make sure the plug wires are in the right order, because a sudden misfire problem as bad as you are describing really sounds like wires out of order to me. It shouldn't start doing that just from putting the old plugs back in, if they weren't causing that before (unless you damaged one while cleaning).

Personally I would just get some AC Delco or NGK iridium plugs and put those in. For the plug wires, they should be in this order. When standing at the front of the car looking at the engine, the posts on the coil packs from left to right go to cylinders 5, 2, 3, 6, ,4, and 1. The cylinder order is from left to right, cylinder 1, 3, and 5 on the rear bank, and 2, 4, and 6 on the front bank.

eBandit
11-20-2009, 10:26 PM
old plugs aren't damaged from cleaning cause they work with the old coil packs back in. I'm certain I didn't put a wire on wrong though, because when I just changed the plugs back while the new coil packs were still on, I did them one plug at a time so only one wire was off at a time.

The old plugs didn't cause that before but that was with the old coil packs. After changing the autolite out and putting the old ac delco back in, it got worse and ended up with the misfire, so now the old packs are back in with the old plugs (new wires still) and I'm back to where I was before the tune-up (or tune-down in my case).

I only got the accel packs for the brass terminals.

I only went down the street and it got worse as driving, the light wasn't flashing until less than 1/4 mile from home so I didn't go far. you don't think that would have damaged anything that quick do you?

Pauljp
11-21-2009, 07:16 AM
Maybe it's time to try something else.
Try what AaronGTR said on Nov 18.
Clean the MAF and EGR.
It doesn't cost anything and it wouldn't hurt.

350rs
11-21-2009, 08:48 AM
now correct me if i am wrong ( and often am with this car..) But arent the OE plug types in this motor Iridium? Not platinum? With that being said, ive also heard it can cause problems ( idle, hesitation, poor mileage, so on and so forth) to run something other than OE "material"? I put NGK Iridiums in mine, and aside from the occasional high idle that many of us seem to have, my car runs like a champ.

BTW, i figured out the OE type while working at Oreilly, under the Delco part numbers it gave the Iridium as the OE type but obviously listed several platinums as well.

just something to think about if all other options are exhausted.

eBandit
11-21-2009, 09:42 AM
Maybe it's time to try something else.
Try what AaronGTR said on Nov 18.
Clean the MAF and EGR.
It doesn't cost anything and it wouldn't hurt.

I had planned to clean the MAF all along just hadnt got the cleaner yet, I was trying to figure out why things got so worse after the tune up. Today hopefully I'm doing that and also the EGR like he said to do. I have had to clean the MAF on this car several time since i had it, one shop told me it was cause the K&N filter leaving fibers or the oil onto the wire in the MAF.

I have not been driving the car since all this either.

When I looked up info on the a/c delco plugs, I seen that they were platinum plugs, but that's not 100% factual info either. Would make since for them to be Iridium tho, since they cost the same as the NKG plugs.

IanGT99
11-21-2009, 12:27 PM
^^^ I can tell you from personal experience that most of your problem is coming from a dirty MAF. I clean mine religiously. Anytime you clean, re-oil, or replace your air filter, the oil does get sucked into the intake slightly. It doesn't hurt the engine once it's in there, but it does attach itself to the sensors inside the MAF. I was having REALLY bad fluctuations at idle. I cleaned my air filter and replaced my spark plugs. It helped a bit, but after a few weeks, it just went back to where it was. I then took apart my intake and pulled off the MAF. The sensors were FILTHY. Keep in mind these sensors are tiny and fairly fragile, so you have to be careful. I use either a little brake cleaner or rubbing alcohol on a cotton swab to clean the crap off. Then I go back with some filtered water to get rid of any residue left over from the cleaning agent. I put everything back together, and the rough idle was totally gone. Try that asap and see if it takes care of your problem.

350rs
11-21-2009, 12:45 PM
CRC makes a MAF cleaner in an aerosol. Dries quick and works well. Made a good difference on my dads 3100.

lvemy3100
11-21-2009, 12:45 PM
dont use rubbing alc or brake cleaner to clean your MAF... use a sensor safe cleaner from your local parts store.. there is an actual MAF Cleaner specific spray that can be has as well

MMGT1
11-21-2009, 01:02 PM
I would clean the MAF and check the little wires, there is two of them, leading to your IAT sensor. One of mine was cracked, only a strand or two holding it, and my car did exactly what you are describing.

eBandit
11-21-2009, 01:52 PM
CRC makes a MAF cleaner in an aerosol. Dries quick and works well. Made a good difference on my dads 3100.

that's what I was going after in a bit.

IanGT99
11-21-2009, 02:09 PM
dont use rubbing alc or brake cleaner to clean your MAF... use a sensor safe cleaner from your local parts store.. there is an actual MAF Cleaner specific spray that can be has as well

Brake cleaner or rubbing alcohol may not be the most ideal substance to clean the MAF sensors, but I've had no problems with it whatsoever. I'm still on my original MAF after 11 years and 137,000 miles and I've cleaned it over a dozen times using my alcohol/brake cleaner/cotton swab/clean water technique. I would recommend the specific cleaner, but as I've stated, I've seen no problems at all.

AaronGTR
11-21-2009, 04:38 PM
I use CRC electrical cleaner on mine. Basically you should just use something specifically meant for electronics that you know won't hurt it.

For those accel coils, you said you wanted them for the brass posts... that really isn't necessary. Brass can corrode too. Regular silver color posts are fine. The key to either one is, use some dielectric grease on them, and on the spark plug ends too. That will keep them from corroding and make it easier to get the plug wires off when you need to.

For the spark plugs, they actually changed what is OE mid cycle. The car originally came with AC Delco double platinums. Later model years they started using AC Delco iridiums as the factory plugs (which are just rebranded NGK's).

350rs
11-21-2009, 09:43 PM
For the spark plugs, they actually changed what is OE mid cycle. The car originally came with AC Delco double platinums. Later model years they started using AC Delco iridiums as the factory plugs (which are just rebranded NGK's).

any idea when? i assume like 02+? Since GM made a lot of changes in 02 it would make since to me

eBandit
11-21-2009, 11:09 PM
I always use dielectric grease on stuff like that, they had plenty on them. I have tons of the stuff.

AaronGTR
11-22-2009, 08:39 AM
any idea when? i assume like 02+? Since GM made a lot of changes in 02 it would make since to me

I don't recall exactly but I think it was '03.

350rs
11-22-2009, 09:09 AM
I don't recall exactly but I think it was '03.

yikes, so the car ( and mine) might indeed be platinums. Hmm. Seems to be running fine though?

GrandAmMe
11-22-2009, 09:10 PM
Any info on how the MAF cleaning went?

eBandit
11-22-2009, 09:56 PM
Any info on how the MAF cleaning went?

I'm doing it in the morning, had a bad day today. I got the CRC MAF cleaner though. stuff was almost $9 after tax, I have all kinds of electric contact cleaner and the like, but didn't want to take any chances so I bought the crc stuff.

I'll update as soon as I do the MAF and clean the ERG valve too tomarrow.

Thanks everyone for all your help http://img259.imageshack.us/img259/5919/winking0001.gif

IanGT99
11-25-2009, 09:59 AM
It's way past tomorrow... lol

eBandit
11-26-2009, 12:08 AM
Yeah I know. Wasn't feeling the best. Busy to boot.

No one around here seems to have an EGR valve gasket and I am out of material to make one. Luckily last night PepBoys had just got some of the "help" brand screened EGR valve gasket sets in that have 2 gaskets for various GM and Fords. So I'll probably clean it tonight I hope.

I did though clean the MAF and it was super dirty!!! (black gunk all over and the aluminum port part leading to it was corroded badly which I cleaned up as well) On a hunch I left the old coil packs in (and new wires still) and stuck the new Autolite Platinum plugs in and it ran just fine. I figure one, two or all three of the Accel Coil packs are bad? That must have been why things got worse when I tuned it up.

No SES light is on right now and with new wires and the plugs as well as cleaned MAF, the car has more pull out power than it has had in a long time! (I assume the clean MAF helped this?) runs better already but I'm sure the EGR still needs cleaned cause the original problem was intermittent which would coincide with the EGR valve stuck open code- at times.

But night and day difference in acceleration right now.

IanGT99
11-28-2009, 06:20 PM
^^^ I knew it! The MAF is a critical part of the intake system and it throws off all kinds of red flags when that signal doesn't get to where it needs to go. A clean MAF leads to a smooth running vehicle...

eBandit
11-28-2009, 11:33 PM
i did what i could with the egr valve, hard to clean but got lots of black carbon running out after scraping with a dental pick inside and using carb cleaner to spray out. its back on but haven't cleared the codes and driven it yet, been busy

thanks everyone for the help ;-)

IanGT99
12-22-2009, 10:30 AM
Bringin' it back from the dead, but any results from the MAF cleaning??

zukiracer19
12-22-2009, 01:03 PM
Best engine fix is seafoam... for an old motor... :D

eBandit
12-23-2009, 06:22 AM
Bringin' it back from the dead, but any results from the MAF cleaning??

Big time. Car runs better and has more pull out and passing power than it has had since I bought it!



Best engine fix is seafoam... for an old motor... :D

what benefit does seafoam have? I use Rislone with the oil now cause I had sticking lifters I think once making noise, but not anymore since I started using it.

[ChaosweaveR]
12-23-2009, 08:34 AM
Use seafoam through the vacuum line, makes a HUGE difference.

IanGT99
12-23-2009, 10:15 AM
I've been using Seafoam for years now. I've never used it through the vacuum line, but it might be worth it. Search for Seafoam and you'll get tons of results. I use half a can in the oil a few days before I do an oil change (drive at least 50 miles), and then the other half of the can in the gas tank. It cleans EVERYTHING. You can actually feel a difference after only a few miles of driving. The car is more responsive and just runs better overall. I also use a can of Engine Restore in fresh oil. It does a very good job of reconditioning seals, freeing up sticky lifters and restoring compression. You can get Seafoam at specialty auto parts stores and you can get the Engine Restore at Walmart. Total cost is around $18 and I do this treatment every other oil change. 140,000 miles and still running very strong.

Glad to hear the MAF cleaning went well. Any time you have any sort of idling or acceleration problem, check the MAF first. It only takes 6 months or less for the thing to get gunked up again. I usually clean mine twice a year. Takes 15 minutes and makes a world of difference.

[ChaosweaveR]
12-23-2009, 02:00 PM
Use Seafoam in the vacuum system, here's how I do it:

You'll need a buddy to sit in the car, and keep the engine rpms up.
Disconnect the main vacuum line off the brake booster. Turn the engine on, and pour 1/3 of the can of Seafoam into the line. The rpms will bog down, even stall the motor a few times. Keep the revs up until 1/3 is in.
Turn the car off. Don't worry if it sputters, some cars do this, mine did it the first time I did it.
Wait about 10-15 minutes, for the Seafoam to seep in, and break up the carbon build up.
After waiting, start up the car, and keep the rpms between 2K-2.5K. White smoke will pour out from the muffler, this is completely normal. It's all the built up carbon being burnt off. It'll take anywhere from 10-30 minutes for the smoke to stop, depending on how bad the carbon build up is.
Hope this helps, and good luck with the Seafoam.

2000 GT Coupe
12-23-2009, 02:15 PM
I too recommend seafoam, however if your needing it more then once a year your car has some other problem, and if your seeing lots of carbon build up often enough to need seafoam you have some real issue's with that car.

IanGT99
12-23-2009, 08:20 PM
^^^ It ends up being twice a year for me. Bottom line is that Seafoam is amazing stuff. It's shown that it's starting to catch on because just two years ago you could pick up a can for just under 6 bucks. Now it's over 9. I don't care if it's 30, I'll still use it.

Chris, could you snap a pic of the vacuum line you're talking about? I'm not exactly sure which one it is...

2000 GT Coupe
12-23-2009, 08:23 PM
^^^ It ends up being twice a year for me. Bottom line is that Seafoam is amazing stuff. It's shown that it's starting to catch on because just two years ago you could pick up a can for just under 6 bucks. Now it's over 9. I don't care if it's 30, I'll still use it.

Chris, could you snap a pic of the vacuum line you're talking about? I'm not exactly sure which one it is...

Its the large one that goes to the brake booster. This is just a generic I found on the net, but you can plainly see the brake booster and the large hose attached.

http://i990.photobucket.com/albums/af22/TheDude1982/Outerenginebay.jpg

[ChaosweaveR]
12-23-2009, 10:09 PM
Yup, Gene's pic shows it, that's the line.

DoCDooM
01-02-2010, 11:06 AM
The long standing problem with the MAF on N-Body cars is well documented and believe it or not is NOT caused by K&N oil filters.

K&N did some serious examination of the buildup on GM MAF sensors for several cars and concluded that the soot that builds up on them is composed of burnt silicone from the MAF sensor itself. Faulty by accident or design the problem is entirely of GM's making.
K&N's oil has no silicone content.

AaronGTR
01-02-2010, 04:15 PM
^mmm, I don't really believe that for a second. Not that many people actually have problems at all with their MAF's or they don't have recurring problems. I ran my stock one for years without a hiccup. Of course, I didn't have any problems with it with any of the aftermarket filters I used either. I think if the filter is kept clean and is not over oiled by the end user, it isn't a problem.

IanGT99
01-02-2010, 08:30 PM
The long standing problem with the MAF on N-Body cars is well documented and believe it or not is NOT caused by K&N oil filters.

K&N did some serious examination of the buildup on GM MAF sensors for several cars and concluded that the soot that builds up on them is composed of burnt silicone from the MAF sensor itself. Faulty by accident or design the problem is entirely of GM's making.
K&N's oil has no silicone content.

Yeah, I don't believe that either. Do you really think K&N would say that the oil from their filters causes build up on the MAF and therefore makes the car not operate correctly? I think not. They did their "testing" to make it look as if they actually cared about the effects of the oil on the intake system. They care about selling filters and intake systems. I'd like you to show me where there is silicone anywhere near the inside of the MAF and also how it gets anywhere near hot enough in the intake tube for said imaginary silicone to burn. I'm still on my original MAF that is 11 years old and has nearly 140k miles. Still works like a gem as long as it's clean.

I clean and re-oil my air filter when it needs it. I don't live in a dusty area, so it ends up being about every 18 months. I clean my MAF and TB twice a year, once in October before winter and once in April after winter. No matter how light the coating of oil is that I put on my filter, it ALWAYS gets on the MAF sensors and gunks up my TB plate. Cleaning those two parts after re-oiling the filter is always more involved than a cleaning when I don't re-oil the filter. The car starts to run much worse as well after a few months after the filter re-oiling due to the excessive gumming. If you wanna do some real testing, run a regular paper filter with the stock air box and a clean MAF for two months. Check the build up on the MAF and throttle plate. Then install a WAI or CAI with an oiled filter. Then check the build up. You'll see a significant difference. Oiled filters provide many advantages, but they require a lot more meticulous cleaning.