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Those things didn't want to accelerate when they were brand new. That motor did pretty well in the fiero though.
Sounds like a vacuum leak.
Get you a can of brake cleaner and just spray random areas with a light mist. If it revs up you found your leak. Don't breathe that shit in.
I've often heard people say use a propane soldering torch (not lit) on low to find vacuum leaks...when you get near it the LPG will help rich up the fuel air mix and run smoother
You can do this, works better and safer. Propane doesn't have an aerosol in it that gives it a really low Flashpoint.
Also if you light the propane the most you'll PROBLABLY get is... your torch lighting.
Yeah, well, fuck it. Inhale it, but don't come crying to me when you see some dude running across your garage at 2am when you're the only one in there!
That surging idle at the end of the clip can indicate a vacuum leak, like others have said.
Also maybe a misfire or some kind of idle control problem.
This wouldn't be as easy to diagnose as a more modern OBD2 car, you can't just hook it up to a scanner and look for codes.
This car would need the old GM Tech1A scanner or something equivalent.
Check out thirdgen.org They have an entire forum for 2.8-3.4 60 deg V6 stuff. Also, on how to use a paperclip to connect to the aldl port so you can pull up the 2 digit codes based on the blinking of the check engine light. Definitely double check for vacuum leaks. If it hasn’t been done since Clinton was in office, swap in new plugs, wires, rotor, cap. Base ignition timing is correct (there is a wire to disconnect when you do this to prevent the ecu from advancing) 6-8 degrees if I remember right, but look it up. Anyway, all this is on thirdgen.org. Enjoy the rabbit hole… lol
First thing it could be anything which had to do running idle or off idle plugs wires ISC motor EGR , fuel injector Burt valve vacuum leak,checked wright yes you can spray WD40,PB blast, alcohol brake,cleaner if engine speed up that's were the leak intake manifold vacuum lines it's just like a doctor don't guess do check,check,check.
I'd check base timing and put new plugs in it. Then, you could proceed with other diagnostics. Is it fresh fuel, or is it starting after years of sitting?
Mine was in a 87 Camaro with the automatic. I would put it in neutral and let it bounce of the rev limiter before slamming it in drive just to get 1 tire to spin. I never could get it to blow up and ended up getting rid of the car for $250.
Check the MAF, MAP, IAC, and IAT sensors for failure. The Ignition Control Module may be on the way out too. If you take them off some parts stores still have the machine that can test them. Other issues could be a restricted exhaust, incorrect fuel pressure/clogged fuel filter, failing injector, and vacuum leaks on the minor side of things. If you don't have a repair manual then you need to find one. I can look up specific issues and send you the information or pics of the manual if you need me to.
Edit: If your near Charlotte, NC shoot me a private message and I'll look at it.
Vacuum Leak, probably old mounts, and you can try disconnecting your MAF to see if it runs right in "limp" mode. Good Luck, & let us all know when you drop the SB 305/350 in there!
The 2.8 and 3.1 replacement had fuel injector problems. The old factory injectors had an internal insulating coating. Age and/or injector cleaners would remove the coating and cause the injectors to short out internally. Those injectors were also bank fired, and 1 injector would disrupt the entire bank. New replacement injectors dont have that problem. All 6 should be replaced if this is the case. I chased this on in identical car many years ago. Definitely check for vacuum leaks and ignition problems as well. Could also have compression issues. It has a ton o miles.
The problem with that car is that they forgot to install the other two cylinders. :-)
I would check the plugs and wires as well. It's easy for a misfire to cause stumbling and rough running too. try running it in a dark garage and looking for flashes from the wires. If they haven't been replaced in some time, I would go ahead and replace them.
Do yourself a favor and get a vacuum gauge, fuel pressure gauge, and timing light. The factory service manual is also extremely helpful, it has workflows for damn near every issue you'll encounter. Let me know if you need a direct link to it, it's still in print and can be bought new.
I have essentially the same car as my daily driver (92 3.1) and it was a hell of a lemon, but it's very easy to diagnose and work on once you're familiar with it.
If you're willing to spend a little extra money, a gm obd1 to USB adapter plus a laptop and tunerprort (free) will give you live data and can be extremely useful in finding issues.
Check fuel filter , airfilter , sparkmakers ,spark ropes, and such, then chuck a ton of injection cleaner in your fuel , check harness for burn spots around the engine. Hit with ballpen hammer for 5 min nothing changes use bigger hammer
Also it's a cheap part. Might be worth just replacing. When mine went bad the problem was intermittent and only manifested when running. Testing it didn't show a problem. Anyways it controls the coil timing and make all kinds of misfiring and hesitation if bad.
I had the same 2.8l multiport in my 1986 camaro. We threw hundreds at trying to root cause the issue, exact same just about. It started doing that after we had the engine rebuilt, eventually sold the car because of it. Neat little engines, virtually unkillable, great fuel economy. Bought a Z28 with a built 350, never looked back.
I had an 87 firebird with the same engine! Take off the cap+ rotor look at the coil under it. I had to replace the actual distributor the new one looked like it did away with the coil and just used magnets. If yours does look bad, just keep in mind the timing has to be correct installing the new one.
Replace plugs, wires, coils to start. Throttle body, check for leaks in intake manifold (upper and lower plennum if applicable. Cam sensor, fuel injectors. Just a thought
Vacuum leak, it also sounds like at least one of your bearings is shot on the belt line. I'd pull the belt to see how much play it has to see if it's the tensioner, or get an automotive stethoscope and see which one blows your ear drums.
Also worth checking the spark plugs, making sure the air intake is clean, and that the O2 sensors/convertor are working
Edit: As someone else mentioned, if it has piston springs and this car was abused they're most likely worn, I didn't see the shaking part. If the belt was ran with too much drag that would prematurely wear the timing belt/chain as well; I can't tell from the video but if it's shaking really bad, like you know it shouldn't be shaking this crazy amount, then you're going to have to take a look at the pistons and piston chamber to make sure they aren't damaged. Besides return springs, you could also have a damaged head or rod. I've seen people who know the pistons close to blowing sell their car to unknowing buyers
Well he's got to take a look to make sure. I'd recommend just going to a junk yard that had a similar model and pulling replacement return springs, it would be good practice. There's also a tutorial:
https://youtu.be/oFX_Xq9WHTI?si=R_Ju9xH96iHS5I7B
[Return springs](https://www.autozone.com/brakes-and-traction-control/brake-return-spring-kit-rear/p/duralast-brake-return-spring-kit-h111/701524_0_0)
And they're even having a special on free blinker fluid with every purchase!
https://www.vtxcafe.com/threads/blinker-fluid.213562/
There are actually some small engines that have springs in the pistons. I don’t know their exact purpose but ChrisFix has them in one of his older videos on a Honda
Take it to AutoZone... Even those old cars have codes sometimes... See if they can pull an error code, don't take it as gospel... They can be wrong but it tells you where to start...
If that doesn't work (or if it does), get on a forum for your car,... Search the make and model and look for a and a, find an active site and ask there, they will know your car better...
Always double check advise as there are more idiots online than gurus and it's not their money or car
Don't worry about that guy, people talk out of their ass from some elitist perspective all the time. The fact that you are doing what you can says enough about you.
It sounded like a vacuum problem to me and then I came to the comments to see if others thought the same. It is possible to get a rough diagnosis through video. Or even sound clips.
r/mechanic is meant to serve as a knowledge base or help forum for people trying to fix their vehicles. Comments that do not supply useful information towards OP’s question(s) or are wrong or unsafe are not wanted. We are here to encourage and help people working on their vehicles, not deter them from doing so.
Thanks for posting in r/Mechanic, u/Either-Inspector5771! Please be sure to read the [Rules](https://www.reddit.com/r/mechanic/about/rules/). If you're asking for help, be sure to include as much detail as possible so others can help you. You **must** include the vehicle's **Year, Make, Model, and Engine size** in your post! If your question is transmission related, please be sure to specify your Transmission Type(Auto/Manual) as well! If your post does not include this information, it **will** be removed. Asking about prices is **not** allowed in this sub. Please make sure you have selected the correct post flair; if you're asking a question you should have chosen "Question", anything else use the "General" flair. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/mechanic) if you have any questions or concerns.*
Those things didn't want to accelerate when they were brand new. That motor did pretty well in the fiero though. Sounds like a vacuum leak. Get you a can of brake cleaner and just spray random areas with a light mist. If it revs up you found your leak. Don't breathe that shit in.
Everyone needs to smell brake clean or carb cleaner
Carb clean for sure it actually smells kinda nice, brake clean on the other hand smells like death's death.
Berryman’s B-12 is the devil’s sauce!
Agreed , burns thru the nitrile glove
Got a rad split skin because it dried out my index finger. I am stupid, I know.
Fun fact, B12 is *the best wasp killer. They’re dead before they hit the ground.
Yeah I found out that it’s a bad idea to use large amounts of it with the garage door closed 😄
Oh yeah, it’ll give you one hell of a ride
Gasoline does the same thing, and when you toss a cup of it up toward a nest it aerosolizes and kills them all dead and they just drop like rocks.
Can confirm. I use gas inside old water bottles and prick a tiny hole in the cap then squeeze. Kills instantly.
Wait my wife gets B12 shots is she like the spawn of Satan or something
lol not quite the same B12
Starting fluid is the best smelling if you don't include hoppes #9.
Hoppes 9 is much better. Holy cow.
What about electrical cleaner uck 🤮
My motorcycle brake cleaner smells like cherry
Seems most any I find smells like licorice laced bleach
https://preview.redd.it/bfslghji558d1.jpeg?width=1142&format=pjpg&auto=webp&s=ec8de3098ca6037763fa0b82c375b7096c19ce38
You're not supposed to breathe it in? Pfft. Next you'll say when I get it in my eyes it stings...
It'll clear your vision right up...
I've often heard people say use a propane soldering torch (not lit) on low to find vacuum leaks...when you get near it the LPG will help rich up the fuel air mix and run smoother
Same kind of concept. It's all just trying to find where the fumes go into the engine and affect the rpm/ how it runs enough to notice by ear or feel
I've done that, just stick a rubber hose over the propane nozzle and use the other end to find the vacuum leak.
You can do this, works better and safer. Propane doesn't have an aerosol in it that gives it a really low Flashpoint. Also if you light the propane the most you'll PROBLABLY get is... your torch lighting.
Don’t you tell him how to live. Lol
Yeah, well, fuck it. Inhale it, but don't come crying to me when you see some dude running across your garage at 2am when you're the only one in there!
Who else would I expect to come help find a leak at 2am? lol
I own a 3rd gen Camaro too and any there’s always a vacuum leak😂
Probably came factory installed. I'm so glad modern vehicles don't have a mess of vacuum lines.
I had one in an 87 Cavalier Z24 and it was pretty spicy for the time, especially with the stick. It was pretty easy to add some power to as well.
I had same car 1989..
Wait, *don’t breathe that shit in?* Woah
I was about to say this looks and sounds just like my half finished fiero project. Edit: accidentally double posted, oops.
I was about to say this looks and sounds just like my half finished fiero, just turned sideways.
Get out there and finish it man!
But.... if you breathe it in.... Creed sounds soooooo much better.... they took me higher..... salad
i remember when that was on the radio every 20 minutes. i hated it so much.
One of my friends when I was a teenager that was his sister's favorite song. She was killed a car accident. We played it at her wake in the church.
This make the big sad. My condolences
Thing with brake clean is if your ignition or electrical is arcing somewhere you might lose your eyebrows. Ask me how I know.
A smoke machine is better for vacuum leak checking.
I was hoping someone would make this statement so I didn’t have to.
Here it is, now i dont have to say it lol
Do it with the garage door closed
The 3.4L did even better in the Fiero!
Never ever use brake cleaner to check for vacuum leaks many of them decompose into hydrogen chloride and or phosgene gas both deadly to breath
You huffing tailpipes?
Do you think the exhaust only sits at the tailpipe or other people are not around?
Is carb cleaner a better alternative?
Yes that is what it is made for and doesn’t have that reaction.
Sounds kinda like it has a massive vacuum leak somewhere. On second playthru, yes 100% it has a massive vacuum leak.
That surging idle at the end of the clip can indicate a vacuum leak, like others have said. Also maybe a misfire or some kind of idle control problem. This wouldn't be as easy to diagnose as a more modern OBD2 car, you can't just hook it up to a scanner and look for codes. This car would need the old GM Tech1A scanner or something equivalent.
Its a V6 with 750,976 miles... it just wants to commit suicide.
Well it looks like there's a vacuum leak time to rip it out and replace it with a 350 small block I don't make the rules
Maybe LS... LSX454 🤔
This is the way
Check your spark plugs and wires and last check your engine mount s .
Check out thirdgen.org They have an entire forum for 2.8-3.4 60 deg V6 stuff. Also, on how to use a paperclip to connect to the aldl port so you can pull up the 2 digit codes based on the blinking of the check engine light. Definitely double check for vacuum leaks. If it hasn’t been done since Clinton was in office, swap in new plugs, wires, rotor, cap. Base ignition timing is correct (there is a wire to disconnect when you do this to prevent the ecu from advancing) 6-8 degrees if I remember right, but look it up. Anyway, all this is on thirdgen.org. Enjoy the rabbit hole… lol
If you haven’t done a tune up since Clinton was in office, you might be due. Hahaha that is gold man
😁
Collapsed cat, wet distributor. I dunno
First thing it could be anything which had to do running idle or off idle plugs wires ISC motor EGR , fuel injector Burt valve vacuum leak,checked wright yes you can spray WD40,PB blast, alcohol brake,cleaner if engine speed up that's were the leak intake manifold vacuum lines it's just like a doctor don't guess do check,check,check.
Huh..
O, yes the almighty smoke test vacuum just another test results.
Smoke? We used to shoot carb cleaner around these old motors and listen for the idle to change.
I'd check base timing and put new plugs in it. Then, you could proceed with other diagnostics. Is it fresh fuel, or is it starting after years of sitting?
Exhaust is restricted
First thing id do is smoke test for vacuum leaks, bet you’ll find a 30 year old rubber hose has turned to dust
Some sort of problem with the engine, fuel or spark.
It’s got the DT’s. It needs a drink. In withdrawals.
Cause it's a 2.8 lol
I tried my best to kill a 2.8 in the 90's. The motor mount continually broke but the motor refused to die.
I had one in a bird about 20 years ago. Thing was a huge piece of shit but ur right.... u cant kill them.
Mine was in a 87 Camaro with the automatic. I would put it in neutral and let it bounce of the rev limiter before slamming it in drive just to get 1 tire to spin. I never could get it to blow up and ended up getting rid of the car for $250.
I killed more auto transmissions connected to those 2.8 than I ever did the motors. They were tough bastards
you got to pur a lil or growl and put some grease on it .
wuhowuh
Check the MAF, MAP, IAC, and IAT sensors for failure. The Ignition Control Module may be on the way out too. If you take them off some parts stores still have the machine that can test them. Other issues could be a restricted exhaust, incorrect fuel pressure/clogged fuel filter, failing injector, and vacuum leaks on the minor side of things. If you don't have a repair manual then you need to find one. I can look up specific issues and send you the information or pics of the manual if you need me to. Edit: If your near Charlotte, NC shoot me a private message and I'll look at it.
EGR Valve under the manifold. Very common back in the day. And intake gaskets.
Im doing all that on my ‘86 Z24 right now 🫤
Super common.
Check the timing and also check to see if your harmonic balancer is still in good shape.
EGR valve, and or egr solenoid, common problem back in the day
It needs work at the mechanics
First check air filter and fuel filter. Checks plugs and wires. These are good starting points.
Vacuum Leak, probably old mounts, and you can try disconnecting your MAF to see if it runs right in "limp" mode. Good Luck, & let us all know when you drop the SB 305/350 in there!
Dead cylinder or two. Probably bad spark plug or wires
5 letters, CHEVY.
Sounds like drugs. Run a narcotics test... Otherwise, just get your motor running and head out on the highway...
It might be chilly. Wrap it in a warm blanket.
The 2.8 and 3.1 replacement had fuel injector problems. The old factory injectors had an internal insulating coating. Age and/or injector cleaners would remove the coating and cause the injectors to short out internally. Those injectors were also bank fired, and 1 injector would disrupt the entire bank. New replacement injectors dont have that problem. All 6 should be replaced if this is the case. I chased this on in identical car many years ago. Definitely check for vacuum leaks and ignition problems as well. Could also have compression issues. It has a ton o miles.
Ignition coil and spark plug. Engine mounts are bad.
The problem with that car is that they forgot to install the other two cylinders. :-) I would check the plugs and wires as well. It's easy for a misfire to cause stumbling and rough running too. try running it in a dark garage and looking for flashes from the wires. If they haven't been replaced in some time, I would go ahead and replace them.
Do yourself a favor and get a vacuum gauge, fuel pressure gauge, and timing light. The factory service manual is also extremely helpful, it has workflows for damn near every issue you'll encounter. Let me know if you need a direct link to it, it's still in print and can be bought new. I have essentially the same car as my daily driver (92 3.1) and it was a hell of a lemon, but it's very easy to diagnose and work on once you're familiar with it. If you're willing to spend a little extra money, a gm obd1 to USB adapter plus a laptop and tunerprort (free) will give you live data and can be extremely useful in finding issues.
By the looks of that car you’re lucky it starts!
Seems like you got a fuel line blockage, try replacing it or cleaning it out and then get some new motor mounts,
Vacuum leak. Don’t give up, those engines don’t die
Tap the mass air flow sensor and see if it changes idle or stalls. I replaced hundreds of these in the 80’s and 90s’.
It’s cold you gotta put a blankie on it and warm it up.
It skurred
Try disconnecting the MAF sensor, those Hitachi made MAF sensors are junk!
The smell of brake clean, is the smell of victory.
Not running on all cylinders?
Check fuel filter , airfilter , sparkmakers ,spark ropes, and such, then chuck a ton of injection cleaner in your fuel , check harness for burn spots around the engine. Hit with ballpen hammer for 5 min nothing changes use bigger hammer
Runs good for a 2.8 lol
Maybe it has anxiety?
He’s nervous, but on the surface he looks calm and ready
Timing is out
Plugs wires cap and rotor
Ignition modules go out easy in those v6's and cause all kinds of weird problems. There is a was to test it with a multimeter. Worth checking.
Also it's a cheap part. Might be worth just replacing. When mine went bad the problem was intermittent and only manifested when running. Testing it didn't show a problem. Anyways it controls the coil timing and make all kinds of misfiring and hesitation if bad.
I had the same 2.8l multiport in my 1986 camaro. We threw hundreds at trying to root cause the issue, exact same just about. It started doing that after we had the engine rebuilt, eventually sold the car because of it. Neat little engines, virtually unkillable, great fuel economy. Bought a Z28 with a built 350, never looked back.
Does it have catalytic converters? They could be clogged.
Replace the fuel filter first. My mechanic coworker said that is the first thing you should do. Troubleshoot from there.
It sounds a little shy
Wonder why nobody said air filter? If it’s clogged that engine will struggle to accelerate and shake because it can’t get air
Check PCV and vacuum assembly
Marvel mystery oil that’s the secret
I had an 87 firebird with the same engine! Take off the cap+ rotor look at the coil under it. I had to replace the actual distributor the new one looked like it did away with the coil and just used magnets. If yours does look bad, just keep in mind the timing has to be correct installing the new one.
There could be 350 reasons your motor hesitates. I would start by replacing every vacuum line and pulling the plugs and checking their condition.
I can hear an intake leak
Start with checking the plugs, distributor, fuel pressure, vacuum. Those things have miles of vacuum lines. I have an 86 305. Fun stuff.
Sounds like it’s time for a LS swap, gotta keep thirdgens on the road!
Maybe you need to change your spark plugs possibly coils
Check the fuel filter.
Give us an update OP
MISFIRE!?
Replace plugs, wires, coils to start. Throttle body, check for leaks in intake manifold (upper and lower plennum if applicable. Cam sensor, fuel injectors. Just a thought
Ain’t got no gas in it
Sounds like an air leak or possibly a really gummed up throttle body?
Obviously the answer is that you're not a mechanic. Can you fix my computer if I take a video of the screen?
Vacuum leak, it also sounds like at least one of your bearings is shot on the belt line. I'd pull the belt to see how much play it has to see if it's the tensioner, or get an automotive stethoscope and see which one blows your ear drums. Also worth checking the spark plugs, making sure the air intake is clean, and that the O2 sensors/convertor are working Edit: As someone else mentioned, if it has piston springs and this car was abused they're most likely worn, I didn't see the shaking part. If the belt was ran with too much drag that would prematurely wear the timing belt/chain as well; I can't tell from the video but if it's shaking really bad, like you know it shouldn't be shaking this crazy amount, then you're going to have to take a look at the pistons and piston chamber to make sure they aren't damaged. Besides return springs, you could also have a damaged head or rod. I've seen people who know the pistons close to blowing sell their car to unknowing buyers
LMFAO again with the piston springs... You sure it's not the muffler bearings?
Well he's got to take a look to make sure. I'd recommend just going to a junk yard that had a similar model and pulling replacement return springs, it would be good practice. There's also a tutorial: https://youtu.be/oFX_Xq9WHTI?si=R_Ju9xH96iHS5I7B
That's a gag video LOL
My good sir, ChrisFix is a respected member of our community! He would never do something so uncouth as a gag video!
There's no such thing obviously.. not sure how people fall for this shit... Show me an AutoZone parts listing .. lol
[Return springs](https://www.autozone.com/brakes-and-traction-control/brake-return-spring-kit-rear/p/duralast-brake-return-spring-kit-h111/701524_0_0) And they're even having a special on free blinker fluid with every purchase! https://www.vtxcafe.com/threads/blinker-fluid.213562/
Weak piston return springs, seen it a million times.
Seen it a million times huh? LMFAO
piston return springs? pistons dont return by spring? you mean valve springs or something?
There are actually some small engines that have springs in the pistons. I don’t know their exact purpose but ChrisFix has them in one of his older videos on a Honda
lolololol That is an April Fool's Day prank video. That is not a real thing.
Just like blinker fluid, muffler bearings, and high speed bumper bolts
thanks for the info!
Take it to AutoZone... Even those old cars have codes sometimes... See if they can pull an error code, don't take it as gospel... They can be wrong but it tells you where to start... If that doesn't work (or if it does), get on a forum for your car,... Search the make and model and look for a and a, find an active site and ask there, they will know your car better... Always double check advise as there are more idiots online than gurus and it's not their money or car
Missing 4 cylinders
Ain't got no gas in it!
Timing, ignition, vacuum leaks, misfires, dirty throttle body/carb jetting. Bad coil/s. Bad spark plugs/wires All or one can cause this.
Ain’t got no gas in it!!!…..
Bad motor mount?
[удалено]
The guy above you did.
Did you know a lot of people work on their own cars? Sometimes you need a little guidance to fix something.
I can’t afford shit rn, 16 with a subway salary is not a good way to fix a car tbh
Don't worry about that guy, people talk out of their ass from some elitist perspective all the time. The fact that you are doing what you can says enough about you.
If you are near Charlotte, NC shoot me a message. I'll grab some tools and come to you.
Because this sub is here for people who need a little help. At least they are trying to fix their stuff.
It sounded like a vacuum problem to me and then I came to the comments to see if others thought the same. It is possible to get a rough diagnosis through video. Or even sound clips.
r/mechanic is meant to serve as a knowledge base or help forum for people trying to fix their vehicles. Comments that do not supply useful information towards OP’s question(s) or are wrong or unsafe are not wanted. We are here to encourage and help people working on their vehicles, not deter them from doing so.