While driving engine shuts off

Tiny
YASIRDAHHAM
  • MEMBER
  • 1995 PONTIAC GRAND AM
  • 2.3L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 240,000 MILES
My engine stalls all of a sudden every time I am driving the past 5 months. The instruments panel still shows the typical red light of the alternator and other warning lamps but the engine looks either starving for fuel ( which I doubt much because the fuel pump is always working with its noise audible to me) or the electronic ignition is failing instantaneously in an almost systematic mode because it never reaches a terminal problem so that my car mechanic can follow and track nor does it stop happening. It is pretty embarrassing when I am waiting for the green traffic light to move but it fails to turn and all those drivers behind me start the noise of horns. Sometimes it takes a few seconds to restart again (putting the transmission on N) but most of the times it takes some whole 2-3 minutes of continuous cranking( using the starter motor of course) that I had to replace the starter motor 3 times in a row only this past month! I tried replacing the crankshaft position sensor, TBS, MAP sensor, Throttle position sensor, ignition key lock( both the mechanical one and the black unit attached to it on the left side of the steering wheel complex), I even replaced the whole Electronic Ignition set including the two coils and the control module along with their containing plastic cover. In some cases it worked alright for a brief time once I implemented the replacing act ( the ignition switch, for instance|) but then it simply reverts back to the annoying symptoms. I am perplexed: is it the PCM? Is it that aluminum case beneath the dashboard drawer next to the front right door or is it some other control module buried deep inside the dashboard? A loose earth wire or a wire making a short circuit may be? I tried a scanner that works with my old and almost obsolete DLC( having only 3 pins/wires) two times in a row at two independent auto scanner workshops but it simply says( The scanner couldn't communicate with your DLC). One important symptom to include, when I crank the engine using the starter( and the engine takes too long to fire alright) the miles/kilometers pointer to the right side of the RPM one shoots up although neither the engine is working right nor the vehicle is actually moving, there seems to be some short circuit here if I am not mistaken. The engine backfires sometimes and there is a smell of gasoline around the engine.
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Saturday, May 29th, 2021 AT 5:37 AM

54 Replies

Tiny
DANNY L
  • EXPERT
Hello, I'm Danny.

It sounds like you might have a weak or failing fuel pump not providing adequate fuel pressure. Have you tested the fuel pressure? I would suggest performing a fuel pressure test. Here is a tutorial showing what is involved:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

After performing this test get back to us with the results and we'll go from there. I've attached a picture below showing the proper fuel pressure for your vehicle. Hope this helps and thanks for using 2CarPros.
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Saturday, May 29th, 2021 AT 7:16 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

You are correct. The PCM is on the passenger side under the dash. I attached a pic below.

The idea if a fuel smell is what concerns me. That can be caused by a loss of spark to the plugs causing unburned fuel to exit the engine via the exhaust. Or, you may simply have high fuel pressure that is flooding the engine.

Do you ever notice black or gray smoke from the exhaust when the engine starts? Does this only happen at an idle? If you hold the throttle to the floor when it won't start, does that make a difference?

The idea that you sometimes hear a backfire is leading me to think of a fuel pressure issue. Also, when the engine isn't running, you shouldn't hear the pump running. When turning the key from off to on, it will prime for about a second or two, but then it should turn off.

Take a look through this and let me know if anything mirrors what you experience:

https://www.2carpros.com/articles/engine-backfires-while-running

Let me know.

Joe
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Saturday, May 29th, 2021 AT 7:19 PM
Tiny
YASIRDAHHAM
  • MEMBER
Thank you dear Joe for caring to respond and that prompt indeed. The stuff you led me to is a mighty content that I am to go through quite thoroughly as it deserves but for the meantime I wish to acknowledge a little thing regarding the continuous buzz of the fuel pump that I mentioned, it is because my car electrician bypassed the PCM, he found that the live feed for the fuel pump relay (you know it, extreme right side of the engine compartment along with 3 more relays) has voltage once but then the voltage disappears suddenly, for some mysterious reason that grey wire had no +ve 12 volts so the guy penetrated the black rubber shield leading to the inside of the car and to the PCM zone and arranged for a bypass wire to reach the line leading to the fuel pump along the right side of the hull (there are two wires, grey one as live 12 VDC feed and a negative/earth black wire), he attached that bypass wire to the fuel pump relay and fed the relay with a hot live (through the switch) 12 VDC and that allowed him to tell if the PCM was causing any problem or not in absence of any means to test the PCM( as the DLC having 3 wires is almost dead, does not communicate with the scanner used). The problem is that even this weird bypass trick didn't save me, once again the engine started to experience the same intermittent stalling. Here in Iraq we do various tricks to manage our problems due to lack of service eqpt and stations. Until next time with an input regarding what you kindly sent, lots of thanks and gratitude.
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Sunday, May 30th, 2021 AT 10:59 AM
Tiny
YASIRDAHHAM
  • MEMBER
So Danny my dear, I found no field to reply for your answer, I wanted to tell you that my vehicle doesn't seem to have any pressure checking facility (valve), all fuel delivery and return lines are tightly sealed connections that demand a special plastic tool to easy detaching. If there had been a check point it would have helped me track and see if the pressure falls at any moment. Still, I needed to know the designated pressure value that you kindly provided, the fuel pumps we use here are all Chinese brands (usually sold here at 10-15 USD/each) with 10 kgf/square cm pressure upon installing. I started with replacing the old fuel pump and the fuel filter to eliminate any probability of a faulty one of these two items. I am talking about some 142 PSI here.
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Sunday, May 30th, 2021 AT 1:22 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

If you have 142 PSI, I'm surprised the entire engine isn't full of fuel. I attached the manufacturer's specs below. You are way above them.

As far as the test port, if there isn't one on the fuel rail, you will need to disconnect the supply hose from the fuel rail and place a T connector there. One side will have a Schrader valve on it and the other two will be for fuel to go through.

If you look at pic 2 below, it shows what I am referring to.

Let us know what we can do to help.

Take care,

Joe

See pics below.
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Sunday, May 30th, 2021 AT 6:37 PM
Tiny
YASIRDAHHAM
  • MEMBER
This is great, I met a car mechanic today and we agreed to admit my car into his garage to arrange for this modification so that fuel system pressure can be recorded. Meanwhile, I am attaching pics of the catalog of my current fuel pump, it is one of these models, all delivering 6 bars (87 PSI), strange how I had been using the same fuel pump (already replaced some 8 pumps since I acquired this car in 2006)! Why did it work fine? The car mechanic expressed his skepticism since there is already a return valve (check valve) attached to the "bridge" that receives the fuel line and feed it to the nozzles! It is supposed to be responsible for relieving the pressure and delivering all surplus fuel back to the fuel tank.
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Monday, May 31st, 2021 AT 6:47 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

There is a fuel pressure regulator which is designed to maintain a specified pressure. It is actuated by engine vacuum. Make sure the hose is connected and there is vacuum to it.

If you look below at pic 1, I attached a picture of the fuel rail and highlighted the regulator.

Let me know what you find.

Take care,
Joe

See pic below.
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Monday, May 31st, 2021 AT 8:34 PM
Tiny
DANNY L
  • EXPERT
Hello again.

It definitely seems your fuel system is over pressurized. I've attached picture steps below on how to replace the fuel pressure regulator including its location circled in red on your Grand Am. Keep us updated. Hope this helps and thanks again for using 2CarPros.
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Monday, May 31st, 2021 AT 8:56 PM
Tiny
YASIRDAHHAM
  • MEMBER
You guys are great. I had been suspecting this valve because there was a hissing tick that I used to hear coming somehow near the space over the exhaust manifold. My mechanic tried choking the fuel high pressure hoses (supply and return, one after the other) to see if things get better but he excluded this valve. Today will be seeing this step, I am grateful for your help and patience.
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Monday, May 31st, 2021 AT 10:09 PM
Tiny
DANNY L
  • EXPERT
You're welcome!
Keep us updated and let us know if you have any further questions on this issue. Thanks again for using 2CarPros.

Danny-
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Tuesday, June 1st, 2021 AT 2:11 AM
Tiny
YASIRDAHHAM
  • MEMBER
Danny L and Joe. Thanking you all for the useful and invaluable assistance provided by you, I benefited a lot and it makes me grateful to you. The mystery was solved this afternoon as I tried replacing the crankshaft position sensor (we don't have any new spares here, imagine how my car is the one and only 4-cylinder Grand Am in all Mosul where I live, all parts that I could replace were second-hand ones). I didn't leave it all to the mechanic and rather cared to take the lead and inspect the wires from the sensor and back to the huge cable, and guess what? The silicone rubber stuff that is usually inside any plastic clip of a sensor (those colored ones with slotted patterns) was swollen and torn in part, the mechanics who dealt with the sensor along the past 8 months used to shove the clip into the sensor and quit once it felt like home.I took it off and replaced it with another brand new one. The engine is alright now, not a single stall! Thanks again and again to you all.
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Tuesday, June 1st, 2021 AT 1:20 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

I'm glad to hear you found the problem. Since it was related to the crankshaft position sensor, you were likely losing spark to the plugs resulting in the fuel smell.

Regardless, we appreciate the update. Please feel free to come back anytime in the future. You're always welcome here.

Take care,

Joe
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Tuesday, June 1st, 2021 AT 7:05 PM
Tiny
YASIRDAHHAM
  • MEMBER
Bless you all dear friend, you are a treasure.
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Wednesday, June 2nd, 2021 AT 3:16 AM
Tiny
DANNY L
  • EXPERT
You're welcome!
Glad to hear you found and fixed the problem. Thanks again for using 2CarPros and we hope you will use our site again in the future when needed.

Danny-
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Wednesday, June 2nd, 2021 AT 4:12 AM
Tiny
YASIRDAHHAM
  • MEMBER
Danny my dear friend, one question please regarding the replacement of the fuel regulator valve. I managed to get one (second hand, as usual, there is no brand new one) but upon trying to replace it it turned out that it is a different layout with the base plate having an Allen bolt to the right rather than to the left as in my own engine. I am attaching an image to clarify things, could the replacement valve be taken from a 6-cylinder engine (for Pontiac Grand Am 6 cylinder)? I tried to loosen the big nut so that I can tilt the plate to the other side and ease its installation on the fuel rail but boy, it could never be turned.
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Thursday, June 3rd, 2021 AT 1:35 PM
Tiny
DANNY L
  • EXPERT
Hello again.

Yes, you acquired a fuel pressure regulator from the V6 engine Grand Am. Although they both supply the required 41-47 PSI pressure they both mount to the fuel rail differently as you are experiencing. You will need to find a 4 cylinder version fuel pressure regulator to mount correctly. Hope this helps and thanks again for using 2CarPros.

Danny-
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Thursday, June 3rd, 2021 AT 1:57 PM
Tiny
YASIRDAHHAM
  • MEMBER
Thanks again and again.
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Friday, June 4th, 2021 AT 1:20 AM
Tiny
DANNY L
  • EXPERT
Hello again.

I'm sorry to hear you are having so much trouble acquiring the correct part. Just out of curiosity where is the most local auto part store near you? Can you order from an auto parts store and have it shipped to you? Just be sure to acquired a new or used fuel pressure regulator for a 4 cylinder engine Grand Am. Hope this helps and thanks again for using 2CarPros.

Danny-
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Friday, June 4th, 2021 AT 1:46 AM
Tiny
YASIRDAHHAM
  • MEMBER
Dearest Danny this is Iraq. We have thousands of auto parts dealers and suppliers but never for this car and its sisters (Buick, Lumina. Etc). These cars had been imported next to 2003 war as "used" ones, they came in quite few numbers and as far as Mosul my town is concerned too many of them got destroyed when ISIS invaded the town. I may be exact if I say my Pontiac Grand Am is the only survivor of them all. I have an Iraqi friend who lives in USA, he once sent me a whole timing case assy, electronic Ignition assy and 2 front suspension struts, he refused to receive any money for that, the struts (quite rare in Iraq) did cost him 28 USD but the freight charge came to 330 USD, thus I do not ask him to do me any more favor. I can get some from UAE may be, in Turkey where I settle a few months per year I failed to locate any dealer that can satisfy my need. Hopefully, tomorrow will see me replacing this for that, the guy who managed it has a whole yard of used engines and body parts, it won't be a big problem as I hope. Sorry for disturbing you with my primitive habitat needs.
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Friday, June 4th, 2021 AT 7:17 AM
Tiny
DANNY L
  • EXPERT
Hello again.

Sorry to hear this. Hopefully you will be able to barter for the correct regulator. Please keep us updated and let us know if you have any further questions on this issue. Stay safe. Thanks again for using 2CarPros.

Danny-
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Friday, June 4th, 2021 AT 8:12 PM

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