Major problems with my Grand Am GT (w/ 2.4 TwinCam) [Archive] - GrandAmGT.com Forum

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82-T/A
08-09-2005, 06:53 PM
Hey guys,

I have a 1997 Grand Am GT. The car runs like crap. It started doing this two weeks ago, and I really want to get this taken care of.

Here are my symptoms. When I first start the car, the car idles perfectly smooth. It'll continue to idle perfectly smooth also without any problems.

The car will accelerate normally so long as I do not give it any more than 1/4 throttle. If I give it like 1/2 throttle, the car will bog down severly.. almost to the point where it'll want to stall out. So much in fact that even when I let up off the gas, it's next to impossible to get the car to stop hesitating.

Just took it out for a spin tonight and I had the same symptoms. When I pulled it back in it's parking space, the car died. I started the car up (with many cranks) and it finally started, just barely... I tapped the gas a couple of times, and then it started to idle perfectly normal again.


When this first happened, I got a check engine light flash on and off. I bought an OBD-II scanner and it gave me a generic error saying "Multiple Cyl Missfires" and that's basically the extent of it. The car gives no other errors.

I also noticed that when I first started the car, I got out and smelled the exhuast, it smelled really rich. Like that one time I installed 19lb fuel injectors in my Fiero's engines instead of the 15lb injectors.


NOW, my questions are:


1 - If either of my Oxygen Sensors are bad, is it possible that they can fail without sending a signal?

2 - Can I test to see if the O2 sensor is bad by disconnecting it? Will the car still run (although very rich?)

3 - If it's my fuel pump, would it really act like this, or wouldn't it fail completely?

4 - Is there a way for me to check my fuel pressure? I've got a fuel pressure gauge, but I don't see a schrader valve anywhere on the fuel rail.

5 - Any other ideas what it could be?


I cleared that cyl misfire code, and there are no other error codes.


Any help is really appreciated. This car runs like crap, and I'm so tired of dealing with it. It ran flawlessly before then. I have new plugs in it, clean Redline Synthetic oil, the transmission filter and fluid were just changed 10k miles ago... the car is up on it's maintenance...



Thanks... :( :nono:

GlisteningWhite
08-09-2005, 07:29 PM
My car is doing the same thing i tought it was my injectors, but it wasn't brought it to the dealership and they said it was my spark plug wires, so i bpught a new set and still, same ****, then i replave spark plugs nothing!!! I can't take it anymore i just drive it to work and back! If anyone else has this going on please let us know!!! Help!

82-T/A
08-09-2005, 07:47 PM
Well, I guess it's good that I'm not the only one.

FYI, I just got through replacing the main oxygen sensor. I had a spare one which I knew was good (got it from my other 97 Grand Am that I used to have).

I also replaced the top IDI cover... the thing that the coil pack is built into that says "2.4 TWINCAM". I replaced that with a good one from my old car too.. same thing.

So I've ruled out the main O2 sensor, and the ignition coils.

I'm totally confused...

I know there's one more O2 sensor behind the catalytic converter, but I don't still have the old spare one.

Any ideas guys??

:(

Metallman56
08-09-2005, 08:27 PM
it could be 2 things. i put bosch quad platnum in my grand am and multiple cylinder misfire came up with my scaner, i put ac delco back in light went off car runs fine. if its not plugs or a fuel problem which you have ruled out what about a air problem. like the mass airflow senser. it sounds like its starving for something and if it aint fuel or spark theres only one other thing it could be. air. look at the wires right by the top of the throttle body make sure there all ok, and hell even check you air filter. that cant hurt anyrhing.
hope it helps

82-T/A
08-09-2005, 08:59 PM
it could be 2 things. i put bosch quad platnum in my grand am and multiple cylinder misfire came up with my scaner, i put ac delco back in light went off car runs fine. if its not plugs or a fuel problem which you have ruled out what about a air problem. like the mass airflow senser. it sounds like its starving for something and if it aint fuel or spark theres only one other thing it could be. air. look at the wires right by the top of the throttle body make sure there all ok, and hell even check you air filter. that cant hurt anyrhing.
hope it helps


Well, you make an interesting point.

But, I don't think my 2.4 TwinCam has a MAF sensor. I don't see one anywhere in the intake.

However, someone mentioned to me on another board that it could be my MAP sensor...

I didn't even know the car HAD a MAP sensor.. but I think maybe it's that little itty bitty thing. I'm used to seeing MAP sensors from the 80s which are huge...

I'm going to see if I can find the spare one I had from my old car and swap it out!

Thanks!

DevilSlayer
08-09-2005, 09:47 PM
What plugs did you put in? Like Metallman56 said, and is a well known fact here, that bosch plats cause multiple misfires. Go get some AC Delco's and put those in and see how it runs.

82-T/A
08-10-2005, 06:37 AM
What plugs did you put in? Like Metallman56 said, and is a well known fact here, that bosch plats cause multiple misfires. Go get some AC Delco's and put those in and see how it runs.


I have original stock steel tipped AC DELCO plugs in there... I changed them out around 68 thousand miles. The car has 88 thousand miles and I recently bought 4 new AC DELCO plugs that I was planning on installing when I got the chance.

Someone suggested to me that it might be the MAP sensor... what do you guys think?

It does seem to perform similar to how my V6 Fiero did a long time ago when the MAP sensor failed. I guess the only difference was that the Fiero had a V6 so, like GlisteningWhite's V6 Grand Am (above), it had enough power to allow you to continue driving, but just not with any real acceleration.

MetaGTP1
08-10-2005, 06:45 AM
Have you changed the ignition cables(spark plug wires) recently?

action
08-10-2005, 07:38 AM
The 2.4l dont have plug wires, it has those little caps becuse the coils are on the engine cover which he already replaced with no change.

82-T/A
08-11-2005, 04:22 PM
Well, the MAP sensor didn't do the trick.

I'm bummed...


Because I have a spare engine (and whatnot), I think I'll try swapping out the TPS and the Fuel Pressure Regulator.

They're both pretty easy to get at, and it won't cost me anything except maybe an hour of work in my driveway....


If that doesn't fix the problem, then my guess is the fuel pump, maybe....

:gablackbu

Metallman56
08-13-2005, 12:14 PM
probley not the fuel pump, those tend to just die not act up. however there is some sort of screen on the fuel pump in the tank that could be clogged from perhapes rust in the tank. also if i remember right there are like 3 things that plug into the side of your throttle body check all of those. also perhapes theres something wrong with the throttle body opening up. take the airbox thing off and have a friend press the gas and see how open the throttle body opens up,but dont turn the car on. if all of this doesnt work i have one more suggestion. . . buy a new car or engine. good luck dude hope it helps

82-T/A
08-13-2005, 12:16 PM
probley not the fuel pump, those tend to just die not act up. however there is some sort of screen on the fuel pump in the tank that could be clogged from perhapes rust in the tank. also if i remember right there are like 3 things that plug into the side of your throttle body check all of those. also perhapes theres something wrong with the throttle body opening up. take the airbox thing off and have a friend press the gas and see how open the throttle body opens up,but dont turn the car on. if all of this doesnt work i have one more suggestion. . . buy a new car or engine. good luck dude hope it helps


Yeah, I know... tell me about it. I've got a Solstice on order... but I won't get that for another 2 months...

I love driving the Vic, but it's massive and sucks gas...


Thanks... I'm going to swap some parts out today and see what I can get it to do...

Undersexed
08-13-2005, 10:41 PM
I had that problem one time on my old saturn and it was a coolant temp sensor... it was reading way too cold and was telling the car to dump fuel to the engine or something, but it came up on diagnostics(dealership of course)...

Metallman56
08-17-2005, 04:27 PM
any luck?

82-T/A
08-17-2005, 07:12 PM
No, I still haven't fixed it yet. It's not my primary vehicle so it's just sitting there right now. I'm SOOOO f**king ****ed at this car.

I'm guessing it's the fuel pressure regulator. If it's not that, then I just have no clue what it could possibly be.

I just cannot understand how a car with 88k miles could have SOOO many problems with it. My other 97 GrandAm went to 117k with no problems.

If the FPR doesn't fix this, I think I'm just going to donate the car.

The computer gives me absolutely no codes except "Multiple Misfires Detected!"

Metallman56
08-17-2005, 10:28 PM
hey i just thought of something. try valvaline syn fuel injecter cleaner. its like $7 but it could clean all the crap out of your fuel system. its worth a shot!

82-T/A
08-18-2005, 06:39 AM
hey i just thought of something. try valvaline syn fuel injecter cleaner. its like $7 but it could clean all the crap out of your fuel system. its worth a shot!


Well, I don't think that's my problem. About 6 months ago, I already used the BG Chemical Cleaner fuel injector cleaner. I use it on all my cars every 30k miles.

Metallman56
08-28-2005, 09:52 PM
any luck?

O1GAGT
08-29-2005, 12:11 AM
Check the fuel pressure at the rail, how old is the fuel filter?

Check the throttle position sensor voltages, if your sensor is bad this could cause what you are expierencing.


Also check the coolant temp sensor

It honestly doesn't sound like the Fuel Pressure Regulator to me

82-T/A
08-29-2005, 06:35 AM
Thanks guys,

I'm going to try to fix it this weekend, I've just been really busy with cleaning up the mess this hurricane left.

I'll let you guys know...

thanks for the advice.

Mike Jung
08-29-2005, 12:42 PM
Don't know if this helps, but I came across it looking for something else...


from thread: Ses Po300!!!!! (http://www.grandamgt.com/forum/showthread.php?p=433375#post433375)
DTC P0300
Circuit Description
The powertrain control module (PCM) uses information from the shaft position (CKP) sensors and from the camshaft position (CMP) sensor in order to determine if engine misfire is occurring. By monitoring the variations in the shaft rotational speed for each cylinder, the PCM is able to detect individual cylinder misfire events. A misfire rate that is high enough can cause damage to the 3-way catalytic converter (TWC). The malfunction indicator lamp (MIL) will flash if TWC damaging conditions are present.

Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0116, P0117, P0118, P0125, P0128, P0335, P0336, P0341, P0343, P0502, P0503, P1114, P1115, P1120, P1220, P1221, or P1336 are not set.
The engine speed is between 375-5,001 RPM for an automatic transmission.
The engine speed is between 450-5,001 RPM for a manual transmission.
The ignition voltage is between 10-18 volts.
The engine coolant temperature (ECT) is between -7 to +130C (19-266F).
The fuel level is more than 10 percent.
The throttle position (TP) sensor angle is steady within 1 percent.
The antilock brake system (ABS) and the traction control system are not active.
The transmission is not changing gears.
The secondary air injection (AIR) diagnostic test is not in progress (RPO NC1 only).
The A/C clutch is not changing states.
The PCM is not in fuel shut-off or decel fuel cut-off (DFCO) mode.
The ABS signal is not exceeding rough road thresholds.
Conditions for Setting the DTC
The PCM determines that an emission type misfire is present.
The PCM determines that a catalyst damaging misfire is present.
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids

Important
Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Verify that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.


Running the vehicle out of fuel causes sufficient misfire to set DTC P0300. A vehicle that is out of fuel may have fuel level DTCs also set.
A restricted fuel filter can cause sufficient misfire to set DTC P0300. Refer to Fuel System Diagnosis .
Excessive vibration from sources other than the engine can cause a misfire DTC. The following are possible sources of vibration:
Variable thickness brake rotor
Drive shaft not balanced
Certain rough road conditions
Observe, if more then one cylinder is misfiring, the scan tool may only display one cylinder misfiring. This will not be apparent until the repair is completed. Also, if an ignition coil ground circuit is open for one side of the engine, the scan tool may only display 2 or 3 cylinders misfiring. Inspect the ground circuit for the ignition coil on the cylinder bank of the engine that has more then one cylinder misfiring.

97GT
09-29-2005, 12:04 PM
Its funny to hear about this because I'm having the same problem with my other car right now 97 Taurus SHO. the same symtoms. the dealership found out that my vacuum regulator was bad, egr sensor, tps and my mass air flow sensor/meter. changed the vacuum regulator,egr sensor. car still cuts off on my here and there but it runs alot better than before. my next thing to change will be the tps and may be the mass air flow sensor. now i dont know if the grand ams have a vacuum regulator or anything like that but it could be a check valve or something of that nature.

Lab Rat
09-29-2005, 12:27 PM
Most of you will already know this but if you have a disconnected vacuum line or cracked/broken line your car will run like s%^&. Make sure you check those before spending tons of cash. $.02

82-T/A
09-29-2005, 12:33 PM
Its funny to hear about this because I'm having the same problem with my other car right now 97 Taurus SHO. the same symtoms. the dealership found out that my vacuum regulator was bad, egr sensor, tps and my mass air flow sensor/meter. changed the vacuum regulator,egr sensor. car still cuts off on my here and there but it runs alot better than before. my next thing to change will be the tps and may be the mass air flow sensor. now i dont know if the grand ams have a vacuum regulator or anything like that but it could be a check valve or something of that nature.



Actually, I STILL haven't fixed it yet. :irate:

It just kinda sits there on my driveway and I start it up, wash it every weekend, and put it back.. hahaha..

The BIGGEST problem is that the car doesn't shoot any trouble codes at all... that makes it difficult to diagnose. The problem being of course is that if it didn't have any of this computer emissions crap on it, then it would never suffer these problems. It would be other problems, and they would be easy to diagnose.

Never the less, I think I've more or less narrowed it down to a few key items:

1 - Fuel Pressure Regulator
2 - Throttle Position Sensor
3 - Fuel Pump


I sort of doubt that it's hte fuel pump since the car still runs, and it starts easily. I suspect really that it's more than likely the fuel pressure regulator, but that's a real pain in the ass to replace.

I used to own another 97 GrandAm, It was a 97 Grand Am SE. Never had any problems with it. A family member totalled it, and I stripped it before collecting insurance and having it junked.


I was cleaning out my garage and I found the throttle body and intake manifold from the old motor (which I still have), and I think I'm going to swap them out this weekend on my black 97 GT if I have time.

The throttle body has two sensors on it. One of them is the TPS and I'm not sure what the other is. I know it was working when it was pulled, so if this corrects the problem, then I'll be happy. Although, like I said, I doubt it's the TPS, as more than likely... the computer would be shooting a code if the TPS was bad. Since there are no fuel sensors that I know of, I suspect that it's more than likely the fuel pressure regulator.


The 97 Grand Am does not use a MAF system. Pontiac has ALWAYS preferred to use a speed density system in their cars wherever they can. (even though lately, almost every new car uses MAF).

Your Taurus probably uses a MAF system. A MAF sensor, as it gets older and begins to fail, usually won't display any error codes, but you'll typically suffer from symptoms of studdering, shuddering, and sometimes hard starting.


Anyway, I'm going to swap this stuff out, and maybe get a new FPR this weekend too and see if it fixes the problem.

82-T/A
09-29-2005, 12:36 PM
Most of you will already know this but if you have a disconnected vacuum line or cracked/broken line your car will run like s%^&. Make sure you check those before spending tons of cash. $.02


Hey, isn't Kenosha where "That 70s Show" is supposed to take place? Heheh..


Yeah, I replaced them all a while back.


I had a problem with the one that goes to that little ity bity MAP sensor.

The car was hesitating and running like crap.

I fixed that a while ago though, all the vacuum lines on it now are new.

Lab Rat
09-29-2005, 12:41 PM
Ya I think so. Good luck, just wanted to threw that in since my son's Cutlas needed some new vac lines and he's running great again.

Lab Rat
09-29-2005, 12:44 PM
And be sure to post pics of the Solstice. I was at the stealership yesterday and asked when we get to see one. Any day now he says, (but that's the same answer I got a month ago). The wife says she wants one but got to pay off the other car loan first. Hope they still make them in 2008.

82-T/A
09-29-2005, 01:46 PM
And be sure to post pics of the Solstice. I was at the stealership yesterday and asked when we get to see one. Any day now he says, (but that's the same answer I got a month ago). The wife says she wants one but got to pay off the other car loan first. Hope they still make them in 2008.

I'll be sure to post them when I get it!

Heheh...

I put a downpayment on one back in June... but the dealer doesn't expect that I'll get mine until November. I'm number 17 on his list... and he only gets 12 for his first allocation. (non 1st 1000). So, realisticaly... I probably won't get it until February... hahah... oh well...

The crazy thing is though, that Pontiac has already hinted several times that they are beyond what they thought would be their initial capacity. I'm glad I ordered as early as I did. Most dealerships aren't even taking new orders because they know they won't be able to get a 2006 model.

stewartsolsi
09-29-2005, 07:37 PM
I am also having the same issues w/ recently rebuilt 96 GAGT. Before rebuild, it had a new cat, O2 sensors, plugs/boots....after rebuild got new map sens, throttle body, tp sens, and most of the vacuum lines.....STILL RUNS LIKE ****! by what everybody else has done, think our problem is either the FPR, or possibly the ECM. I had a 93 delSol w/ same issues that I replaced everything on, got real ****ed and sold for cheap only to watch somebody replace the ecu, and drive another 100K. Let me know how you guys turn out.

atc3434
09-29-2005, 09:44 PM
Fuel pump, sounds like the kinda problems I've had with a car. It would start and idle fine, but once you really started demanding fuel, you'd **** everything off and it would get fussy. Usually if I backed off the pedal, it would be fine again. Check the fuel pressure. A scan tool is invaluable for this kinda stuff too, might be worth looking into. I bought my aeroforce intercetor for less than $200, best money ever spent!

Metallman56
10-01-2005, 06:40 PM
man this is like a bad soapoprah.

MantaGreen97
10-01-2005, 07:35 PM
The 97 Grand Am does not use a MAF system. Pontiac has ALWAYS preferred to use a speed density system in their cars wherever they can. (even though lately, almost every new car uses MAF).

Sure they do. The 96-98 with a 3100/L82 do indeed use a MAF sensor in addition to the MAP sensor. It's just the 2.4L TC that didn't use a MAF sensor...


he throttle body has two sensors on it. One of them is the TPS and I'm not sure what the other is.

The other should be the IAC (Idle Air Control) motor. This motor drives a pintle which moves in and out letting in more or less air to control the idle speed, depending on conditions.

stewartsolsi
10-04-2005, 08:58 AM
found a fuel rail w/ injectors and FPR for $35. Picking it up Thursday, I'll let you guys know how it turns out.

Cryogenic02GAGT
10-06-2005, 12:07 AM
It definatly sounds like a vaccum or FPR problem. Get your fuel pressure checked and have them check it with the vaccum hose on the FPR on and off. There should be a 10 psi difference (higher when hose is off). Check to see what the stock psi should be and compare. Anyways if there is no change in fuel pressure with the vaccume hose off then you know that it is either the FPR or a vaccum related issue.

Just my experience with fuel injected systems......

Just to add also one might check the 02 sensor on their exhaust collector and see if it isn't bad. This sensor in most GM vehicles also controls timing advance and retard.....