1994 Buick Century, 3.1 V6 Problems! - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Buick When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

Reply
 
 
 
Thread Tools Search this Thread
Old 02-23-2014, 07:05 PM   #1
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Feb 2014
Posts: 19
Thanks: 0
Thanked 0 Times in 0 Posts
danjamesjr is on a distinguished road
Angry 1994 Buick Century, 3.1 V6 Problems!

Hello All!

I currently own a 94' buick century, 3.1 V6 with 104,000 miles. It'* white and it has been absolutely lovely to me... until recently.

A few problems to list:


Upon a cold start (overnight or a few hours) hard starting, once started idles extremely low and can stall
Pushing on the accelerator too far will result in bogging down and possibly stalling, have to "ease" throttle to gain RPM and keep running. Once warmed up for 5-10 minutes, will run OKAY until vehicle is placed under load.
Placing a load on the vehicle (In Drive or Reverse), immediately runs rough, bucks, hesitates, and then gets up to momentum. It slowly works itself to normal the longer it'* running.
Sounds like a possible misfire when running
Fuel pump is NOT making any noticeable sound near rear tire when key is "ON".


Parts replaced (related and non-related):


IAC Sensor
PCV Valve
Coolant Temperature Sensor
Cleaned Throttle Body (TB Cleaner) and MAF Sensor (MAF Cleaner)
New Throttle Body Gasket
Cleaned EGR Passage Way and EGR Valve
Completely new Emissions / Vacuum Harness (All Intake Manifold & Emissions Vacuum Lines)
Fuel Filter
Fuel Pressure Regulator
Oil Change + Filter
Spark Plugs
Alternator and Battery
Sea Foamed Gas Tank


Things I haven't done:


Compression Test (I have the compression tester, might do it soon)
Fuel Pressure Test (Need fuel pressure tester)
MAF Sensor Test (Need multimeter that can test Hz, mine doesn't)
TPS Sensor?
Intake Manifold Gasket Leak Test?


My patience is running low; I am a very patient guy.

Please if any one has experienced this issue before or has any guidance on what to next that doesn't involve a lot of money, I highly appreciate it!

Thanks,
Dan
danjamesjr is offline   Reply With Quote
Old 02-23-2014, 07:26 PM   #2
Senior Member
True Car Nut
 
Soft Ride's Avatar
 
Join Date: Jan 2012
Location: BC Canada
Posts: 3,588
Thanked 340 Times in 302 Posts
Soft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud of
Default

Welcome to the forum Dan!
Wow you sure have replaced a lot of parts!
Did you ever get the car scanned for stored codes?
Did any MiL (service soon or engine light) come on?
Did you replace the spark plug wires?
Soft Ride is offline   Reply With Quote
Old 02-23-2014, 07:34 PM   #3
Senior Member
Posts like a Camaro
 
rjblazer's Avatar
 
Join Date: Jan 2010
Location: Elmira, New York
Posts: 853
Thanked 31 Times in 29 Posts
rjblazer has a spectacular aura aboutrjblazer has a spectacular aura about
Default

I'm not sure what'* wrong. You have done a lot to it. The only thing I can think of is maybe the cat or exhaust restriction. But I am not sure.
rjblazer is offline   Reply With Quote
Old 02-23-2014, 08:53 PM   #4
RPH
Member
Posts like a V-Tak
 
Join Date: Jan 2012
Location: Dayton Ohio
Posts: 41
Thanks: 0
Thanked 6 Times in 5 Posts
RPH is on a distinguished road
Default

First things first Which style 3.1L do you have the Early 94 Gen II or the late 94 Gen III. Your car 94 is a mid year change.

I am going to tell you what I would test:
I would pull the upper intake off (gaskets are cheep) and OHM test my fuel Injectors. I would also make a noid light out of a 194 bulb and make sure I have signal to each injector.

194 blub with wire added to each leg, jam wires in injector power plug. if pluse light will flash. no lightm no power or ground. Light with no flash, no ecm spray signal.

I would also go threw the TPS Test and the EGR valve test. If the EGR pintle is hung in the 'Open' position your engine will not run rightm and codes may not set.
RPH is offline   Reply With Quote
Old 02-24-2014, 02:41 AM   #5
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Feb 2014
Posts: 19
Thanks: 0
Thanked 0 Times in 0 Posts
danjamesjr is on a distinguished road
Default

Quote:
Originally Posted by Soft Ride View Post
Welcome to the forum Dan!
Wow you sure have replaced a lot of parts!
Did you ever get the car scanned for stored codes?
Did any MiL (service soon or engine light) come on?
Did you replace the spark plug wires?
Thanks! Yes I have, a little too many lol.

I can't get it scanned, no shops around have obd1 scanners :(

No CEL

Did not replace spark plug wires.

Thanks
danjamesjr is offline   Reply With Quote
Old 02-24-2014, 02:43 AM   #6
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Feb 2014
Posts: 19
Thanks: 0
Thanked 0 Times in 0 Posts
danjamesjr is on a distinguished road
Default

Quote:
Originally Posted by rjblazer View Post
I'm not sure what'* wrong. You have done a lot to it. The only thing I can think of is maybe the cat or exhaust restriction. But I am not sure.
Yes I've thought heavily on cat but I don't want to spend $100 to figure that out.
danjamesjr is offline   Reply With Quote
Old 02-24-2014, 02:53 AM   #7
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Feb 2014
Posts: 19
Thanks: 0
Thanked 0 Times in 0 Posts
danjamesjr is on a distinguished road
Default

Quote:
Originally Posted by RPH View Post
First things first Which style 3.1L do you have the Early 94 Gen II or the late 94 Gen III. Your car 94 is a mid year change.

I am going to tell you what I would test:
I would pull the upper intake off (gaskets are cheep) and OHM test my fuel Injectors. I would also make a noid light out of a 194 bulb and make sure I have signal to each injector.

194 blub with wire added to each leg, jam wires in injector power plug. if pluse light will flash. no lightm no power or ground. Light with no flash, no ecm spray signal.

I would also go threw the TPS Test and the EGR valve test. If the EGR pintle is hung in the 'Open' position your engine will not run rightm and codes may not set.
How can I tell which generation? I know I've looked at obd port and from what most diagrams say to jump a and b pins to enter diagnostic mode. Well, those pins are not next to each other and completely different.

TPS sensor = 5 volts?

EGR test? The car has a non vacuum powered EGR it'* electronic.

Ehh, not looking forward to taking intake manifold off lol.
Testing with light seems good but doesn't measure if injector is clogged only dead? Does light dim if clogged?

Thanks
Dan
danjamesjr is offline   Reply With Quote
Old 02-24-2014, 08:05 AM   #8
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

i would test the fuel pressure, a failing pump can cause all these issues, and they rent them free with deposit.

tps test;
https://www.gmforum.com/trouble-shoo...sensor-279319/
jwfirebird is offline   Reply With Quote
Old 02-24-2014, 11:20 AM   #9
Senior Member
Posts like a Supercharger
 
Join Date: Aug 2013
Posts: 174
Thanked 7 Times in 5 Posts
tsaw5500 is on a distinguished road
Default

tps sensor will show a 5 volt reference. you are wanting to check output voltage.
tsaw5500 is offline   Reply With Quote
Old 02-24-2014, 02:09 PM   #10
RPH
Member
Posts like a V-Tak
 
Join Date: Jan 2012
Location: Dayton Ohio
Posts: 41
Thanks: 0
Thanked 6 Times in 5 Posts
RPH is on a distinguished road
Default

Quote:
Originally Posted by danjamesjr View Post
How can I tell which generation? I know I've looked at obd port and from what most diagrams say to jump a and b pins to enter diagnostic mode. Well, those pins are not next to each other and completely different.

TPS sensor = 5 volts?

EGR test? The car has a non vacuum powered EGR it'* electronic.

Ehh, not looking forward to taking intake manifold off lol.
Testing with light seems good but doesn't measure if injector is clogged only dead? Does light dim if clogged?

Thanks
Dan
How do you tell a Gen II 3.1 for a Gen III? Look at the upper intake manifold. If it looks like a 1988-1994 style, it;* a Gen II, if it looks like a 1995 to 2002 style it'* a Gen III.

Gen 2 engines are more prone to injector fails.

Either style removing the upper intake is required to access the fuel injectors.

The Test light is connected to the wiring harness on the engine, to check for signal from the ECM to the fuel injectors. Rare on those cars yet 1 out of 1000 might have that issue.

The Injector is checked with a Muilti-Meter on the OHMs Setting. Injectors have to fall between two spec to be acceptable. Injectors not in spec will NEVER fire. GEN II 2.8L & 3.1L engines will often not run at all if one is bad. They will not run at all if two go bad. It'* been a good 8 years since the last one of these I did.

There is a test procedure for Electronic EGR valve. I did it once 10 years ago and don't recall it. Common problem much like 4.3 V6 astro van: carbon chunks hold the pintle open when it should be closed. Others fail in the open position. This allows exhaust gas in to the intake stream at times it should not be entering. This effects the mixture and the ECM freaks out trying to compensate for an issue it can not,.
RPH is offline   Reply With Quote
The Following User Says Thank You to RPH For This Useful Post:
jimmy544 (02-26-2014)
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
1994 Buick Lesabre Problems Davepomrenke Buick 1 02-10-2014 12:44 PM
1994 Buick Century VSS alfpete Buick 2 09-06-2012 08:21 PM
Buick Century stalling, rough idle issues mjrgoodvibes Lounge 24 01-04-2011 01:17 AM
ATTN: Gearheads! 99 Buick Century issues vital49 Lounge 4 01-01-2006 05:02 PM
need a PN for Buick Century 1993 SLE Lounge 2 02-06-2005 11:26 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 09:00 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.