Weird electrical happening, car struggles to turn on, shut down

electrical-wiring
engines
chevrolet
montecarlo

#1

I’ll do my best to explain my issue.

Since October or November I’ve been having odd issues happening with my 1995 Chevy Monte Carlo LS, 3.1 Engine. Took it to two mechanics and they have no idea the issue. They basically don’t want to spend the money for an older car.

The problem started around late October to November. After hours of errands, I make another pit stop. After about 30-40 minutes, I get in my car and start the engine. There I noticed it would struggle to start, making this struggling, revving sound; pretty loud at times. After a few minutes it shuts off. Again I try to restart, rev, rev, and shutdown. So I waited I think 30 minutes before restarting and it was fine. After a couple of happenings with that, just in case I decided I wanted to have my car looked at. After about 40 minutes of driving (I recently moved, until I find a reliable mechanic close by) I parked the car at the shop. After placing the car in park and Just before turning it off, it shutdown.

So come Tuesday (the shop closes on Mondays) I told my guy what’s been going on. So after a few days of checking it and driving, nothing it was fine.

So I picked up my car and about a week later it started happening again. But this time I was driving. I was in heavy traffic on a surface street when all of a sudden the car shut-off. I couldn’t steer the car, nothing. So trying to turn the wheel, I glided to a curb safely. I called my mechanic and told him what happened and he has no idea. All he can tell me it was something electrical. And they checked everything.

After about 20 minutes, the car started fine. But then I hear this weird noise coming from the back. At first I thought it was another car outside with loud music. But the sound is a low muffling, “roooom room room rooooom”. At this moment I’m scratching my head and clueless. So I drive home, check under the hood, all while the engine is running. I’m listening near the exhaust. Have no idea.

Since these incidents, I realized if I drive for long periods of time and the engine is not cooled off long enough, I start having these issues. It’s gotten to the point where now when I’m only driving for 2 hours, including stops here and there, it feels like it’s getting worse. I can drive it’s just that it struggles, like a slight stuttering. When I put the a/c on pretty noticeable.

The timing is not right now to get a new car. :confused:

Let me know if there is anything I missed or doesn’t sound right.


#2

May have a couple issues. First a bad fuel pump. Second a bad crank sensor.


#3

My two guesses: ignition module, ignition coil.


#4

Ugh…thanks guys…yeah I mentioned about the fuel pump, but my regular mechanic check it and said they looked into that. But I will mentioned the other 3, thanks guys!


#5

Is your check engine light on? If so, have you had the codes read? Can you post them here?


#6

As noted, you need to post error codes if there are any.

It it wasn’t done, the mechanic needs to do more than just a quick static (or even just idling) check of fuel pressure. They need to see if the system holds fuel pressure when shut down and on a restart. The weird noise from the back was probably from the fuel system and was probably from something like air or fuel vapor running through the return line to the tank.

There may be other issues, however.


#7

The sound you heard in the rear may have been from the fuel pump. It could be getting weak and that is causing the trouble. The fuel pump relay should also be checked to make sure it is okay along with the wiring to the pump. One thing that can be done to check the power out is to monitor the fuel pump current at the fuse location for it in the dash fuse panel. If the current is fluctuating a lot then something isn’t right.


#8

Yeah about the Check Engine light, I never had that fixed, smh. It was around 06-07 where it started malfunctioning and it hard to get a reading. At the time 2 previous mechanics told me it would cost $300 to fix the computer. But then one told me that you really don’t need it fixed.

So as time went by I just never fixed it. I pushed it aside to fix other major appears.

After this happenings, I kept thinking this would have been a great time to have the light fixed for diagnosis.

Cigroller and Cougar, yeah it sounds about right in terms of the fuel pump. And I’ll definitely look into the fuse. Funny I was wondering about the fuse panel yesterday.


#9

Let’s start with a better idea of what the check engine light is all about. It doesn’t need to be fixed, nor does it mean the computer needs to be fixed. The computer monitors the car’s main systems (as it also runs them) and if it see something out of spec it sets an error code. The error code points you to things that need to be fixed.

So…you should get the error codes. If the car a '95 it should be an OBD 1 system and you should be able to get the codes yourself: http://www.obd-codes.com/faq/read-gm-2-digit-obd-codes-free.php Get the exact 2 digit codes and post them.


#10

I should have also mentioned earlier, if the fuel filter hasn’t been changed recently that should be done. It may solve the idle problem if it is plugged up. It’s the simple things a lot of times.


#11

Update: turns out it was the fuel pump. It was so bad I could not accelerate on the freeway or go cruising on the street. It started resisting, hesitating pretty badly and continued struggling to start. What a mission. But it’s done! Thanks guys for all your input!


#12

Great that it’s sorted out and informed everyone as to the cause. In regards to the mechanic claiming the fuel pump was fine it should be kept in mind that pumps can fail in different ways.
They may just die and stay dead.
They may quit, come back to life, and quit again at some point in time.
They may run at slower speeds and cause performance issues while never really stopping completely.


#13

Glad you got it figured out. You’re welcome for the help and thanks for the update.


#14

ok4450 and Cougar, yeah I was freaking out. So far I haven’t the start up issue and idles fine. Thanks guys so much again!