Will L.
Well-Known Member
1993 buick century with 3.3 v6 gas with 166,000 miles.
Currently runs HORRIBLE cold. 5 minutes idle and rough high idle- runs great. No codes.
Ideas?
Now the book of details and parts:
Bil car. He bought it year ago or so and put on probably 12,000 miles no problems. He never did anything other than oil change and quicky lube. (If that)
Couple weeks ago on freeway going up a descent hill- runs out of gas. My wife went rescue him and i sent her with 3-4 gallons of either heavy mixed 2 stroke or gas/diesel mix. (Loaned that can to my nephew who owns 6.2 and a street bike). It smelled like gas but when my bil poured it in he saw it was a little dark he tells me later.
Car never started- tow truck to my house.
Thinking maybe fuel was a little old- I go get 5 gallons of premium grade chevron.
I checked fuel pressure just by hitting schrader vale- low pressure. I swapped fuel filter which is next to tank- very plugged up. Still no start. Disconnect filter and use intank pump to get sample before filter. Dark fuel, tiny amount of water in fuel, rust in fuel. Call bil, this is when he tells me he thinks it was diesel fuel. Only I smelled it and so did a friend of mine that was over who is top notch mechanic- he confirmed not old gas, should be good. So maybe some junk in bottom of plastic can?
With new fuel added and we run till clean fuel comes out, car starts but runs rough. No time to keep messing with it, my big fuel pressure test kit is gone- so just pressing the schrader Valve on engine fuel line we think pressure is low & low volume. Car can drive barely. next day Bil drives car to trust d mechanic in town but doesn’t tell the mechanic what I said about fuel pump.
Mechanic after week of back and forth because bil did not share what i said to tell him...
Replaces all fuel.
New fuel pump (was at minimum spec pressure and volume first time)
Another fuel filter
plugs & plug wires (looked original before going there) check timing
new air filter
new MAF
new temp sensor (known issue for this engine and with cold running problem seems likely guess)
When you first start it cold- 40° or 55° - just engine not ran recently- idle is real rough. After few seconds you can rev up rpm but missing bad. If at idle you put it in gear, engine dies. But after idling for 4-5 minutes or high rpm in park for 2-3 minutes- engine clears up a bit. Put it in gear and drive away. By time you are at 5 mph- runs great. Feels like a car ok to take across country.
All below I did, mechanic did at his shop also.
Checked all the vacuum lines, sprayed starter fluid hunting for vacuum leaks on them, intake, brake booster- no vacuum leaks anywhere we can tell.
Injectors signal the flashing light style tester shows all injectors firing ok.
Removed vacuum line from fuel pressure regulator- no leaking fuel.
New fuel pump 1 psi below top spec, improved flow volume according to mechanic (i haven’t rechecked)
Mechanic added a fuel injector cleaner to fuel hoping some debris may get cleaned up.
But i need my lil pickup back from bil so he has to deal with 1930’s style warm the engine before driving for now.
I read clean electrical ground connections on engine near oil filter so will do that in morning.
The mechanic that did the work is late 50’s pro that I have seen work on things for 20 years- he is top notch usually and amazing on older gas rigs, and new electronic cars as well. Total trust in this guy. He just feels horrible to not have solved this one, but has only few minutes to test with it running before problem disappears, so he gets 2 tries for 3 minutes a day then it has to all cool down.
I am stuck on what else at this point. Still getting over covid and have “covid brain fog” bad right now still. Had to ask for directions to take my son to his dr he has been going to once a month for 6 months today- been eating a restaurant newr that corner for 25 years with my wife- couldn’t envision the intersection. Covid fog SUXXXX!
Ok boys and girls, ideas please?
Currently runs HORRIBLE cold. 5 minutes idle and rough high idle- runs great. No codes.
Ideas?
Now the book of details and parts:
Bil car. He bought it year ago or so and put on probably 12,000 miles no problems. He never did anything other than oil change and quicky lube. (If that)
Couple weeks ago on freeway going up a descent hill- runs out of gas. My wife went rescue him and i sent her with 3-4 gallons of either heavy mixed 2 stroke or gas/diesel mix. (Loaned that can to my nephew who owns 6.2 and a street bike). It smelled like gas but when my bil poured it in he saw it was a little dark he tells me later.
Car never started- tow truck to my house.
Thinking maybe fuel was a little old- I go get 5 gallons of premium grade chevron.
I checked fuel pressure just by hitting schrader vale- low pressure. I swapped fuel filter which is next to tank- very plugged up. Still no start. Disconnect filter and use intank pump to get sample before filter. Dark fuel, tiny amount of water in fuel, rust in fuel. Call bil, this is when he tells me he thinks it was diesel fuel. Only I smelled it and so did a friend of mine that was over who is top notch mechanic- he confirmed not old gas, should be good. So maybe some junk in bottom of plastic can?
With new fuel added and we run till clean fuel comes out, car starts but runs rough. No time to keep messing with it, my big fuel pressure test kit is gone- so just pressing the schrader Valve on engine fuel line we think pressure is low & low volume. Car can drive barely. next day Bil drives car to trust d mechanic in town but doesn’t tell the mechanic what I said about fuel pump.
Mechanic after week of back and forth because bil did not share what i said to tell him...
Replaces all fuel.
New fuel pump (was at minimum spec pressure and volume first time)
Another fuel filter
plugs & plug wires (looked original before going there) check timing
new air filter
new MAF
new temp sensor (known issue for this engine and with cold running problem seems likely guess)
When you first start it cold- 40° or 55° - just engine not ran recently- idle is real rough. After few seconds you can rev up rpm but missing bad. If at idle you put it in gear, engine dies. But after idling for 4-5 minutes or high rpm in park for 2-3 minutes- engine clears up a bit. Put it in gear and drive away. By time you are at 5 mph- runs great. Feels like a car ok to take across country.
All below I did, mechanic did at his shop also.
Checked all the vacuum lines, sprayed starter fluid hunting for vacuum leaks on them, intake, brake booster- no vacuum leaks anywhere we can tell.
Injectors signal the flashing light style tester shows all injectors firing ok.
Removed vacuum line from fuel pressure regulator- no leaking fuel.
New fuel pump 1 psi below top spec, improved flow volume according to mechanic (i haven’t rechecked)
Mechanic added a fuel injector cleaner to fuel hoping some debris may get cleaned up.
But i need my lil pickup back from bil so he has to deal with 1930’s style warm the engine before driving for now.
I read clean electrical ground connections on engine near oil filter so will do that in morning.
The mechanic that did the work is late 50’s pro that I have seen work on things for 20 years- he is top notch usually and amazing on older gas rigs, and new electronic cars as well. Total trust in this guy. He just feels horrible to not have solved this one, but has only few minutes to test with it running before problem disappears, so he gets 2 tries for 3 minutes a day then it has to all cool down.
I am stuck on what else at this point. Still getting over covid and have “covid brain fog” bad right now still. Had to ask for directions to take my son to his dr he has been going to once a month for 6 months today- been eating a restaurant newr that corner for 25 years with my wife- couldn’t envision the intersection. Covid fog SUXXXX!
Ok boys and girls, ideas please?