I got issue...sigh
Thread Starter
Instructor
Joined: Nov 2018
Posts: 126
Likes: 6
From: Boalsburg PA
I got issue...sigh
So this is whats happening with my 95 Base A/T
Last 2 days, she is having an intermittent starting issues.
You drive aroud for a while so everything is up to operating temp. you park your car, and shut the car off. Its been hot last 2 days - 89f today, and was mid 80's yesterday.
she sat in parking lot under the sun for about 45min before I started her back up.
Car starts up right away. But run really shitty. Like as if its running on 5 cylinders, no fuel pressure, or bad timing. barely running at around 500rpm or less. it shakes the car as well.
As its running like crap, if you give it a slight gas to keep it running(I think I kept It at around 2000rpm...) within few seconds, she'll run fine, and idle smooth as she normally would with no issue. Untill you shut the car off again...
and while running like total poo, if you don't give any gas, she'll die.
everything in my car is stock, right down to paper air filter. has 58k miles. 95 Base with 4L60E.
only thing I did was repair the leaky intake manifold over the winter.
No CEL.
Guys, Where should I start?
Last 2 days, she is having an intermittent starting issues.
You drive aroud for a while so everything is up to operating temp. you park your car, and shut the car off. Its been hot last 2 days - 89f today, and was mid 80's yesterday.
she sat in parking lot under the sun for about 45min before I started her back up.
Car starts up right away. But run really shitty. Like as if its running on 5 cylinders, no fuel pressure, or bad timing. barely running at around 500rpm or less. it shakes the car as well.
As its running like crap, if you give it a slight gas to keep it running(I think I kept It at around 2000rpm...) within few seconds, she'll run fine, and idle smooth as she normally would with no issue. Untill you shut the car off again...
and while running like total poo, if you don't give any gas, she'll die.
everything in my car is stock, right down to paper air filter. has 58k miles. 95 Base with 4L60E.
only thing I did was repair the leaky intake manifold over the winter.
No CEL.
Guys, Where should I start?
Last edited by Mity2; Jun 9, 2020 at 03:29 PM.
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
First thing I'd want to look at are some logs. I'd invest in an ALDL cable and then use the free software EEHack to log data while the car is running.
With data, you can look to see if anything is out of the ordinary. It being relating to temperature and fueling makes me wonder about coolant temp sensors and intake air temp sensors.
Anyway, that's my go-to for a '95. Start with data, make sure all the sensors are actually reporting correctly, and fix any that don't. Just remember that only a sensor that fails to connect will throw a code. A sensor that sends incorrect data will not throw a code because the computer has no way of knowing the sensor is lying.
With data, you can look to see if anything is out of the ordinary. It being relating to temperature and fueling makes me wonder about coolant temp sensors and intake air temp sensors.
Anyway, that's my go-to for a '95. Start with data, make sure all the sensors are actually reporting correctly, and fix any that don't. Just remember that only a sensor that fails to connect will throw a code. A sensor that sends incorrect data will not throw a code because the computer has no way of knowing the sensor is lying.
Le Mans Master
Joined: Oct 2004
Posts: 7,706
Likes: 485
From: Everett WA
C4 of Year Finalist (appearance mods) 2019
First thing I'd want to look at are some logs. I'd invest in an ALDL cable and then use the free software EEHack to log data while the car is running.
With data, you can look to see if anything is out of the ordinary. It being relating to temperature and fueling makes me wonder about coolant temp sensors and intake air temp sensors.
Anyway, that's my go-to for a '95. Start with data, make sure all the sensors are actually reporting correctly, and fix any that don't. Just remember that only a sensor that fails to connect will throw a code. A sensor that sends incorrect data will not throw a code because the computer has no way of knowing the sensor is lying.
With data, you can look to see if anything is out of the ordinary. It being relating to temperature and fueling makes me wonder about coolant temp sensors and intake air temp sensors.
Anyway, that's my go-to for a '95. Start with data, make sure all the sensors are actually reporting correctly, and fix any that don't. Just remember that only a sensor that fails to connect will throw a code. A sensor that sends incorrect data will not throw a code because the computer has no way of knowing the sensor is lying.
Aren't there values in the program tables such that if a sensor puts out a reading that is out of the "acceptable range" for that table item..... a code is then generated? Or is it only upon failure?
Pro
Joined: Dec 2017
Posts: 534
Likes: 162
From: Omaha, NE
Issue
You need to get a Factory Service Manual for your year. Check for codes. Search for code reading on this site. I would install a new air filter, just as a maintenance item. You could check some plugs to see if there wet with gas after you shut if off hot. If so your injectors could be leaking. You need to check your fuel pressure with a gage and see if it holds the pressure. It should hold for while. Should have around 40 psi. If it doesn’t then could be injectors and/ or fuel pump. Kevin
Burning Brakes
Joined: Mar 2010
Posts: 1,094
Likes: 68
From: Providence RI
Scan it and see live data. Screams throttle position sensor to me. You can test with a multimeter. I’d start there. They wear in spots and give false readings in certain spots.
i had one that was shot but never threw a code.
i had one that was shot but never threw a code.
Last edited by Deepa; Jun 9, 2020 at 07:49 PM.
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
This exactly. I was going to suggest TPS as well but since it doesn't return unless the car is restarted I didn't want to commit. Looking at live data with a laptop, you'd spot a TPS problem instantly.
Thread Starter
Instructor
Joined: Nov 2018
Posts: 126
Likes: 6
From: Boalsburg PA
Getting live data is the way to go. And normally I use my friends shop for that(they have fancy as soon data logger that I can borrow), but he is still closed due to this whole Corona thing...
I would like to look in to option of using my own laptop and buy cable idea that was mentioned earlier in thread tho
I would like to look in to option of using my own laptop and buy cable idea that was mentioned earlier in thread tho
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Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
Getting live data is the way to go. And normally I use my friends shop for that(they have fancy as soon data logger that I can borrow), but he is still closed due to this whole Corona thing...
I would like to look in to option of using my own laptop and buy cable idea that was mentioned earlier in thread tho
I would like to look in to option of using my own laptop and buy cable idea that was mentioned earlier in thread tho
Software: http://fbodytech.com/eehack-2/download-eehack/
Support: http://www.gearhead-efi.com/Fuel-Inj...GM-EFI-Systems
Good luck!
Thread Starter
Instructor
Joined: Nov 2018
Posts: 126
Likes: 6
From: Boalsburg PA
Cable: http://aldlcable.com/products/aldlobd2u.asp
Software: http://fbodytech.com/eehack-2/download-eehack/
Support: http://www.gearhead-efi.com/Fuel-Inj...GM-EFI-Systems
Good luck!
Software: http://fbodytech.com/eehack-2/download-eehack/
Support: http://www.gearhead-efi.com/Fuel-Inj...GM-EFI-Systems
Good luck!
what exactly does this do? Is it basically a OBD code reader?
Safety Car
Joined: Apr 2016
Posts: 4,648
Likes: 1,059
From: N.E. Ohio OH
Finalist 2020 C4 of the Year - Modified
Which direction was the water running from the leaky intake manifold. If over the front of the engine you might be having Optispark issues, same as if the water pump was leaking water onto it.
A malfunctioning distributor (Optispark) can cause that miss (engine shaking).
A malfunctioning distributor (Optispark) can cause that miss (engine shaking).
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
This cable and software allows you to plug into your car, view realtime data on all sensors at once in a convenient dashboard readout, and even allows you to download the tune from your car and upload new tunes (using the separate program Flashhack).
It's the ability to view all that realtime data that we're suggesting you do. Because that way you can spot sensor readings that are way out of the ordinary.
Thread Starter
Instructor
Joined: Nov 2018
Posts: 126
Likes: 6
From: Boalsburg PA
No, it is far more advanced than that. An OBD code reader is built into the car and you need little more than a paper clip to do that.
This cable and software allows you to plug into your car, view realtime data on all sensors at once in a convenient dashboard readout, and even allows you to download the tune from your car and upload new tunes (using the separate program Flashhack).
It's the ability to view all that realtime data that we're suggesting you do. Because that way you can spot sensor readings that are way out of the ordinary.
This cable and software allows you to plug into your car, view realtime data on all sensors at once in a convenient dashboard readout, and even allows you to download the tune from your car and upload new tunes (using the separate program Flashhack).
It's the ability to view all that realtime data that we're suggesting you do. Because that way you can spot sensor readings that are way out of the ordinary.
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
Burning Brakes
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From: Park City, TN
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Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
The '96 PCM is OBDII, so no. For the '96, you can use any decent OBDII diagnostic program to do datalogging. I have a cheapo $50 OBDScan cable that would work. It'll let you check codes and log data, though that's not quite the same level of detail that EEHack provides the 94-95 cars. Still, the point here is to log data to try to find where the problem is, so yeah.
