350 tpi stumble rough idle
#1
350 tpi stumble rough idle
Just changed my plugs car fires up right away on like one crank now but stumbles and struggles to iddle keeps trying to die but doesnt. What could be the problem i need help fast pleaseeee
#2
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Car: 1975 Novamaro
Engine: 1988 305 TPI
Transmission: 700R4
Axle/Gears: 3.42
Re: 350 tpi stumble rough idle
Have you try resetting the IAC motor? What reading do you have on the TPS at idle? What is your base timing? Have you ever removed and cleaned off the IAC motor? They can get quite a bit of carbon build up on them that will effect their ability to operate properly.
#3
Re: 350 tpi stumble rough idle
Im brand new to this engine dont know where anything is. I have no idea where timing is set. Where is the iac motor so i can check in and clean it.
#5
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Car: 92 1LE B4C
Engine: 350
Transmission: 4L60
Axle/Gears: 4th gen 3.42
Re: 350 tpi stumble rough idle
i would check the iac like sharkbait said and then the map sensor vacuum connection if you are speed density.
#7
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Car: 87 Iroc-Z
Engine: 305 tpi
Transmission: 700-r4
Axle/Gears: 3.42
Re: 350 tpi stumble rough idle
its on the pass. side of the throttle body under the tps sensor. theres a square 4 wire plug going to it.
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#8
Re: 350 tpi stumble rough idle
I will check it out in the morning i have to take care of a vacuum leak i found. All the lines are old so i may just replace them all. Maybe the vacuum leak is whats been causing my car to run realy rich
#11
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Car: 1975 Novamaro
Engine: 1988 305 TPI
Transmission: 700R4
Axle/Gears: 3.42
Re: 350 tpi stumble rough idle
Mine was siezed up pretty good. I found it necessary to remove the throttle body to get a wrench on it and apply the proper leverage to break it loose.
#14
Re: 350 tpi stumble rough idle
sorry didnt fix vacume need to replace the long line that leads to by the right headlight its worn to hell and if i move it where it connects near the passenger rear side of the plenum i can hear air escaping. Also do i need to drain coolant to remove the throttle body? because i cant get anything arround the iac to even start turning it.
#15
Re: 350 tpi stumble rough idle
took it for a spin arround the block before i noticed the second vacuum leak felt a little weak and stubled at stops but not getting any check engine lights
#16
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Car: 88 Iroc-Z
Engine: 6.2 LS3
Transmission: 4L70E
Re: 350 tpi stumble rough idle
You might wanna make sure you didnt crack a plug when you were putting them in. This is how i actually got my car. The PO had installed a new set of plugs and cracked one putting it in, he coudldnt figure out why it wouldnt run right and invested alot of money in random new parts trying to figure out the problem. He never checked the plugs since he had just put new ones in and eventually got frustrated and sold it to me dirt cheap. First thing i did when i got it home was check the plugs, Bingo, 3rd plug back on drivers side was visibly cracked looking at it from under the car
At least check
At least check
#17
Re: 350 tpi stumble rough idle
well i just changed the plugs because of the problem so and before i changed them i was having starting issues but she fires right up now and fir about 5 seconds idles at like 1k then drops and starts to have trouble
#19
Re: 350 tpi stumble rough idle
nope it moved without hesitation. Its not driving like its not getting spark or enough fuel. But it is even richer then it was before i changed my plugs
#23
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Car: 1991 Camaro Z28
Engine: 5.0 LB9 TPI
Transmission: 700r4
Axle/Gears: 2.73 posi drum
Re: 350 tpi stumble rough idle
I had a back fire problem with my tpi, did you try checking the egr valve? Ive heard that can make a car backfire and have a bad idle shake
#25
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Car: 89 Trans Am GtA
Engine: 5.7 TPI
Re: 350 tpi stumble rough idle
i actually have the exact same problem, starts right up stays at about 1thousand RMP and drops between 5-700 rpm and the back end starts to shake. i havent been able to figuer out what it might be yet, but any help would be greatly apreciated
#27
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Car: 87 Iroc-Z
Engine: 305 tpi
Transmission: 700-r4
Axle/Gears: 3.42
Re: 350 tpi stumble rough idle
what does your volt gauge say when this happens. unplug est wire does it run a little smoother. Ive been chasing the same problem for the better part of this year.
#29
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Car: 1989 IROC-Z
Engine: 355, 6.0 (LQ4) soon
Transmission: 700R4
Axle/Gears: Borg Warner 2.77 for now
Re: 350 tpi stumble rough idle
Try cleaning/replacing your O2 sensor, it's always a good thing to do when you replace the plugs, just another routine maintenance item that gets left out.
#30
Re: 350 tpi stumble rough idle
havent checked the 02 sensor but i just cleaned the iac and did the throttle body coolant bypass. and still idleing like **** and gets worse when i put it in gear
#31
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Car: 1991 Camaro Z28
Engine: 5.0 LB9 TPI
Transmission: 700r4
Axle/Gears: 2.73 posi drum
Re: 350 tpi stumble rough idle
I am still having the same problem and i have no codes that show, do you have any codes?
#35
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Car: 1991 Camaro Z28
Engine: 5.0 LB9 TPI
Transmission: 700r4
Axle/Gears: 2.73 posi drum
Re: 350 tpi stumble rough idle
Alright basically if you no where your A and B ports are under the dash you stick one part of the paper clip in the A port and the other end in the B port. The A and B port are to the right and on the top the first two right next to each other. Heres a link that explains it better https://www.thirdgen.org/forums/tech...lip-trick.html Here is the A and B ports http://tunertools.com/vendorinfo/obd1pinout2.gif
#38
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Car: 1991 Camaro Z28
Engine: 5.0 LB9 TPI
Transmission: 700r4
Axle/Gears: 2.73 posi drum
Re: 350 tpi stumble rough idle
It should be right by your battery, look at the first picture. Its in a black cover and you have to open and the fuse is inside. https://www.thirdgen.org/forums/elec...e-problem.html
#39
Re: 350 tpi stumble rough idle
so i cleared my codes and started her to try and use the paperclip trick but now she wont throw any codes but when i rev her to 2 or 3 k im getting sweet smelling smoke from the exhaust and still idling realy rough then if i put it in drive car starts to shake and jump and just dies out. But never throws a code and when i use the paperclip all i get is the 12 the it starts with.
#40
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Car: 1991 Camaro Z28
Engine: 5.0 LB9 TPI
Transmission: 700r4
Axle/Gears: 2.73 posi drum
Re: 350 tpi stumble rough idle
Alright i might have found my problem, a bad coil. Test all you spark plugs by removing the spark plug and once its out plug it into the wire and have someone start the car and obviously have a pair of pliers with the rubber grip and hold it to the exhaust manifold while someone start the car. It should be a powerful and blue spark
#44
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Car: 1991 Camaro Z28
Engine: 5.0 LB9 TPI
Transmission: 700r4
Axle/Gears: 2.73 posi drum
Re: 350 tpi stumble rough idle
The one on the drivers side closest to the front. Drivers side first one in the front
#45
Re: 350 tpi stumble rough idle
i dont think i remembered to point out this whole problem im having happened after driving thru a deceptively deep puddle. It was deep enough that i saw steam from the water getting onto the hot engine comming from my hood.
#46
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Car: 1991 Camaro Z28
Engine: 5.0 LB9 TPI
Transmission: 700r4
Axle/Gears: 2.73 posi drum
Re: 350 tpi stumble rough idle
Most likely you have an electrical problem. I would check cylinder 1 spark.
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