Ok my TGP is having a strange problem, and it only happens while you are going a steady speed and not under boost. For example, yesterday I was driving the TGP down the highway with the cruise set at 70 MPH; it ran fine for the first 125 miles of my trip, but for the last 25 miles, the car would surge and jerk and it would shake the whole car when it did this. The RPM needle didn't move much when it did this, but the boost gauge needle was all over the place in the green "vacuum" part of the gauge. Heres a video I took yesterday on the freeway of the gauge freaking out- (http://i80.photobucket.com/albums/j195/blackswift99/th_October07TGPmeet048.jpg) (http://s80.photobucket.com/albums/j195/blackswift99/?action=view¤t=October07TGPmeet048.flv)
What do you guys think this is? At first, I was thinking MAP sensor, since the boost gauge measures pressure and that would make sense if that went bad, but it happens when you are going a fairly steady speed or light acceleration while not under boost. Also, when you accelerate and do NOT boost, it will do it under that condition also, but lightly. If you accelerate hard under boost, it runs perfect, but once you are out of boost, it comes back. Also, it idles perfectly, doesn't surge or anything at idle... It won't always surge like this, either. The problem comes up at random... it ran fine this weekend during the road trip down to New Ulm (150 miles) and on the way back home it ran perfect for 125 miles and the last 25 miles I wasn't sure the car would make it home..
Any ideas?
My TGP does this from time to time too. What I do to solve the problem is downshift into 3rd gear on the tranny, drive it that way for 10 miles or so, and shift it back into OD. Sometimes that fixes the problem, and sometimes it doesnt.
Other than the bucking and jerking for the last 25 miles, it ran great for the whole trip- I averaged 31 MPG at an avg speed of 62 MPH during the trip.
That would be your TC clutch locking up and unlocking.When it unlocks you vacuum will go up because it's kind of free wheeling until it locks up again.
Fixes. Could be alot of things. Vacuum leak, exhaust leak like a cracked Xover contanimating the o2. Could even be a bad switch but I doubt that. It's on the front of the trans. Could even be an ignition glitch which lowers the vacuum when it misses and the ecm thinks it needs power.
Scares the hell out of your passengers doesn't it. :icon_frown:
Jud
Transmission is new with 15,000 miles on it. I replaced the x-over this spring with a Jeff M. unit and everything is tight. I don't think I have any vacuum leaks, because I had the cruise on and the panel vents on during the whole trip... everything vacuum controlled worked fine... No check engine light, either, even while it is bucking like crazy, there is no check engine light... I find it strange that it only does it at random and often times it works perfectly... like the road trip for example
Any other ideas? :confused:
Also, I don't think it is the TC clutch, because it keeps constant RPMs when it does this.. usually when my TC clutch locks and unlocks, the RPMs will go up/down by ~500 RPMs according to my gauges.
for the hell of it, make sure your aux battery terminal nut is tightened down all the way.
USUALLY when you have bucking it's a lean condition. MAYBE your cat is starting to get clogged and you have more backpressure than normal. That will make the o2 think it's overally rich and the ecm will try to lean things out a little. Just a guess...
I think my cat has been gutted by the previous owner... I think this because it has a really shitty weld all the way around the perimeter of the cat.. it looks like a really thick amateur weld. I could be wrong, but I don't see any other reason why it would be welded like that.
On the other hand, I pulled my front 3 plugs to just check them about a month ago and they were all clean, but were WHITE. I don't know why it would be running lean though. It is completely stock with a Jeff M. crossover, airfilter is clean in stock airbox, has NEW C 302 injectors in it this summer, and I am running non-oxy, non-ethanol 92 octane gas in it.
It does sound like a miss. The vacuum gauge would lean toward that too. Also the white plugs. What heat range plug are you running? stock? colder? When you looked at the plugs was there any build up on them? How many miles are on them. How old is the O2 sensor? Do you have a scanner to look at live data?
Tim
I'm not sure what heat range the plugs are- I know they are regular AC Delcos and I suspect they are the original plugs. I believe the car has original plugs, wires, O2 sensor, and all sensors are stock. The plugs were clean with no buildup on them, but they were white. My neighbor has a scanner, but I'm not sure how in-depth it goes as far as taking sensor readings and such. I was hoping the car would run with the stock equipment until I put it away for the winter, as I was going to do a full tuneup this winter.
Again, I believe everything on the car is stock, other than the injectors (C302 yellow tops), crossover (Jeff M.), and Turbo oil return line (KAZ).
Also, the car has 120K miles on it with original equipment. When it doesn't have the bucking problem, the car runs flawlessly. Will smoke the tires.
Quote from: TGP Nick on October 21, 2007, 05:49:56 PM
Also, the car has 120K miles on it with original equipment. When it doesn't have the bucking problem, the car runs flawlessly. Will smoke the tires.
The plugs need to be changed every 30-35,000 miles. If they are indeed the originals they will need to be changed regardless if it solves the problem or not. Could be that the plugs are so worn that the end gap is larger than the .035 GM recommends. That will create hotter cylinder temps and could cause a lean condition..
What would cause the car to run like this all of a sudden?
Quote from: TGP Nick on October 21, 2007, 06:51:57 PM
What would cause the car to run like this all of a sudden?
Who knows... Maybe it's just time for a tune up, or maybe the o2 is tired and ready for a replacement or both. Pull a plug and check the end gap...
Could be a plug wire breaking down also... It gets pretty hot under the hood of a TGP ;)
1990 spark plug wires i agree. i've had similar problems back in the day... these cars are barely driveable with bad wires in OD.
It didn't do it today, but I know it will start doing it again lol. It really does it at random. Yeah I know it needs a tuneup, I will be doing that once I put it away for the winter at the end of November. Anyone think this is a MAP sensor issue?
if the map sensor was bad or had really bad vacuum source it would throw code 33...
Quote from: flybynite on October 21, 2007, 07:36:37 PM
Could be a plug wire breaking down also... It gets pretty hot under the hood of a TGP ;)
Boy now thats the truth, mine can get so hot I just want to run an airconditioning under there or maybe a mist of Ice cold water.
Well the car started running like complete utter crap. It shuddered worse than ever today on the way home, then I had to drive to town again. I started the car and it stalled right away, so I restarted and it ran for a split second and died again. So I started it again and held the throttle at ~2500RPM for like 10 seconds and took off. It shuddered most of the way to town and as I pulled into a parking lot at ~10 MPH, the engine died again. It restarted right away and ran until I parked it and ran inside a store. I came out and started it again, same drill it stalled once and I gave it some throttle and it stayed running on its own for 20 seconds until I stopped at the end of the parking lot. It stalled there and restarted again right away and shuddered horribly for the 7 mile drive home- I kept it in regular Drive the whole way and kept it under boost as much as possible during the drive (it runs perfect under boost). So now it will idle nice when sitting at stoplights, but when I'm going at low speeds or just starting the car, it will just randomly decide to stall for no apparent reason.
Sorry for the long read, but this is a really strange problem and I'm trying to get in as many details as possible. I called Kyle (Grinders 18) here from the board and he suggested the fuel pump may be on its way out? Anyone have any ideas?
Luckily, the TGP only had to make it today, because tomorrow I am cleaning it up and putting it into my garage until next summer. I will be picking up an 89 GP 5 spd tomorrow morning for my DD for the winter/spring months, so I will have a car to drive during the time I fix the TGPs problems.
Any help is much appreciated!
Any ideas?
Change out your wires, and plugs. I bet you see a big difference.
Quote from: bake82 on November 03, 2007, 08:34:04 PM
Change out your wires, and plugs. I bet you see a big difference.
x2
Assuming that you know your battery and alt output voltages are fine, I too will definitely recommend new plugs/wires.
It has a new battery, but the alt is original and on occasion the electronics in the car would wig out ... I'm thinkin the alt is on its way out too.. like I said its teh original alt.
Here's a prime example of why you need to buy a Wideband gauge Nick. With white plugs your definitely having a lack of fuel issue and you most likely are having an issue with the map sensor (Vacuum or voltage).
Why is it that people have such a hard time doing BASIC maintenance on their cars and when something is running poorly they look for the hardest friggin thing it could possibly be??? :icon_rolleyes:
Yeah put a WB 02 on it and that will tell you what is wrong! Hell put six of them on at each exhaust port to narrow it down even more.
Put a MAP, TPS, IAC, Knock, Crank Position, and Coolant sensor on it too just to make sure! :gr_bs:
Oy evay!
Dude. Look in your owners manual and see what all should have been changed by now (current mileage) and do it. I am sure plugs, wires, fuel filter, air filter, etc are all listed. The harder you make your coils and ICM work to fire off the engine properly the sooner they will die. I would much rather put $100 into plugs, wires, filters, etc than $200 into an ICM and coils and still not have a running car.
If you have a couple of cylinders that are not firing properly then that rich pulse will go past the 02 sensor. It will then lean out every other cylinder until the lean pulses go past. If you have the front 3 cylinders white then guess what most likely is the problem? One or two of the rear three plug wires are most likely arching off onto the intake manifold causing a misfire in the rear three cylinders. That then causes a rich pulse to pass the 02 sensor. If it was intermittent before and now it is progressively getting worse then whatever is degrading is now finally giving up the ghost and BEGGING you to replace them. If you have two or three plugs that are wet fowling because they have no spark...how do you think your motor will run?
How many miles are on that car? How much maintenance has been done to it? If you say, "I don't know" or "I am not sure", then your answer is do everything possible that is in the owners manual to the current mileage of the car. If it still runs like ass then go after every other sensor on the car...but for someone to say...get a WB 02 to diagnose the issue? For $250 you can can damn near replace every sensor on the car!
Sorry I am sounding like an asshole...but I hear this from my customers on a daily basis. Then they are completely surprised how well their vehicle runs after minor maintenance, let alone after I tune the PCM.
I agree with Kenny...everyone knows when you buy a TGP/TSTE, you NEED to replace all your sensors and do a basic tune-up on it immediately...look how many problems I had with my car at first before she got a complete tune-up. Getting the tune-up and replacing the sensors fixed it all! Costly? Kind of...but I definately would have saved myself money if I had done it all right away. And yes Nick, that alternator does need to be changed at some point soon lol :icon_wink:
Another thing I want to add Nick is, you may not have the money right now to put toward the TGP, which is just fine in your situation. I say store that thing away for now, finish school, get yourself a great job, Then start pouring money in the TGP. Cause if your thinking the same way I am, I like knowing that I'm driving a rare car. Please keep it. I strongly believe that you will regret selling it
Holy old topic :laugh: Thanks again for the advice, I will do some of that stuff once funds are built up for it again. Settle down guys, I'm planning on keeping the car. ;)
Thank God!
mine doesn't work, but when it does it jumps down then back up close to zero...