Running REAL rough again....
#11
05-26-2006 | 04:04 PM
Junior Member
Joined: Jan 2006
Posts: 378
From: Northern VA
RE: Running REAL rough again....
Check your EGR Valve, carbon that builds up can flake off and cause the EGR valve to stick open, causing the symptoms youre describing. Spray some intake/carb cleaner in it. This problem is mostly on 95 CPI Blazers. Advance Auto has a EGR valve gasket with a screen to block the carbon. I went through 5 EGR valves before realizing what it was (dealership "couldnt" just clean it, had to replace it). If you look below your throttle body and back in a little, you can see the EGR valve. It only has two bolts, and one electrical connector, you can wiggle it out of the tight spot its in.
#12
05-26-2006 | 05:03 PM
RE: Running REAL rough again....
Thanks for the heads-up... I just finished buttoning it all up, and came in for a nice ice-cold iced tea to cool off with....
Anyway - Yes - I did check the EGR while I had it all open. All clear, and passages leading to the valve are clear (for now).
Rex
Anyway - Yes - I did check the EGR while I had it all open. All clear, and passages leading to the valve are clear (for now).
Rex
#13
06-05-2006 | 12:47 AM
New Member
Joined: Jun 2006
Posts: 2
From:
RE: Running REAL rough again....
I wish I was so lucky. All we have is 10% and I don't like it. I don't have hard numbers, but I'm getting about 20 miles a tank less than I used to. I was driving a rental car for work and I was able to fill up with non ethanol gas and the mileage was noticably higher. Living in NY sucks.
ORIGINAL: swartlkk
Just FYI for everyone, any vehicle produced after '91-'92 will have the fuel system components (viton o-rings) to handle up to a 20% ethanol blend. Beyond that, fuel and timing maps must be modified as to not decrease performance. 4-5 tank fulls wouldn't even begin to be enough time for a 10% ethanol blend to do any harm what so ever.
I for one LOVE how my vehicles run on 10% ethanol and wish that all of the gas stations around me would switch over already! The first few tank fulls will always be the clean out stage where your entire fuel system gets wiped clean of all of the varnish and deposits regular gasoline lays down. After that (in my experience), I have gotten better fuel mileage in my Bonneville and Bravada without any change in the way I drive. I have since moved and do not have a gas station that carries 10% blend anymore.
The rotten egg smell is typical of a clogging cat, but the rest of your symptoms don't sound like that is the problem. Any rich condition will severely shorten the life of the cat. Your fuel system problems prior to now, if the engine was allowed to run for long in that state, could have lead to the current demise of the cat. Additional fuel would be cause for some hesitation and run-on as you described. Try to pressurize the system and see if there are any leak points. Is it possible that an o-ring was damaged during the reinstallation of the new components?
Just FYI for everyone, any vehicle produced after '91-'92 will have the fuel system components (viton o-rings) to handle up to a 20% ethanol blend. Beyond that, fuel and timing maps must be modified as to not decrease performance. 4-5 tank fulls wouldn't even begin to be enough time for a 10% ethanol blend to do any harm what so ever.
I for one LOVE how my vehicles run on 10% ethanol and wish that all of the gas stations around me would switch over already! The first few tank fulls will always be the clean out stage where your entire fuel system gets wiped clean of all of the varnish and deposits regular gasoline lays down. After that (in my experience), I have gotten better fuel mileage in my Bonneville and Bravada without any change in the way I drive. I have since moved and do not have a gas station that carries 10% blend anymore.
The rotten egg smell is typical of a clogging cat, but the rest of your symptoms don't sound like that is the problem. Any rich condition will severely shorten the life of the cat. Your fuel system problems prior to now, if the engine was allowed to run for long in that state, could have lead to the current demise of the cat. Additional fuel would be cause for some hesitation and run-on as you described. Try to pressurize the system and see if there are any leak points. Is it possible that an o-ring was damaged during the reinstallation of the new components?
#14
06-12-2006 | 08:34 PM
Update RE: Running REAL rough again....
Well, things seems to be getting worse with my '95 Blazer.
I took it to my local muffler shop last week, suspecting a clogged catalytic converter. They used a gas cutting torch to make a small hole in the rear of the cat. converter to inspect it while the blazer was running, and the honeycomb insde was glowing red - they say this is a BIG indicator of lots of fuel being dumped into the converter, and the converter is burning it off - thus creating gthe rotton egg smell. The converter is well, and is performing it's job.
Blazer still has the shakes real bad when accelerating... And last night I notices that the freeze plug above the starter motor is seeping/leaking. I'm not nearly equipped enough to takle pulling the engine to do that myself - so it may be time to find a shop to do the work.
Is there a way of testing my MAP sensor / EGR Valve / and the other things that may be causing this running rough situation? I've not had a chance to open up the intake plenum again - but last time I opened it, there was a good spray of oil inside there, and a little accumulation of teaspoon - sized puddles in the lower portions.
Rex S. - who may be in the market for another vehicle soon.... (if I can't get this kicked)
I took it to my local muffler shop last week, suspecting a clogged catalytic converter. They used a gas cutting torch to make a small hole in the rear of the cat. converter to inspect it while the blazer was running, and the honeycomb insde was glowing red - they say this is a BIG indicator of lots of fuel being dumped into the converter, and the converter is burning it off - thus creating gthe rotton egg smell. The converter is well, and is performing it's job.
Blazer still has the shakes real bad when accelerating... And last night I notices that the freeze plug above the starter motor is seeping/leaking. I'm not nearly equipped enough to takle pulling the engine to do that myself - so it may be time to find a shop to do the work.
Is there a way of testing my MAP sensor / EGR Valve / and the other things that may be causing this running rough situation? I've not had a chance to open up the intake plenum again - but last time I opened it, there was a good spray of oil inside there, and a little accumulation of teaspoon - sized puddles in the lower portions.
Rex S. - who may be in the market for another vehicle soon.... (if I can't get this kicked)
#15
06-13-2006 | 01:17 AM
BF Veteran
Joined: May 2005
Posts: 3,890
From: Central Illinois
RE: Update RE: Running REAL rough again....
I'll give ya $50 for it. 
Couple of things.
Hogwash, older vehicles run just fine on 10% ethanol blend. Been running it in my '87 S10-Blazer for over 2 years now. The dealer is blowing smoke up yours. Mgiht be that way on highly tuned caddy engiens, bu the good old work horse 4.3L doesn't have that problem, especially on a '95. My '93 Astro van with a 4.3L only got feed 10% mix and I never changed the fuel filter. I had 286,000 miles on it before I totaled it one mornign on my way to work. Engine was as strong as the day I got it with 60,000 miles on it. Ethanol will clean out your fuel system, and yes it could be a partially plugged fuel filter. By the way, when was the last time you gave your truck a tune up? Air filter could be so plugged that your not getting a proper mix, it could also be a faulty O2 sensor. Defualt mode is to dump fuel, it runs, but like crap. PVC valve? Fuel pressure? spark plug gap, distriburator cap. Any and all of them combined will cuase all sorts of problems.
The best thing to do is check for any codes, and give it a tune up if it has been 3 years or more.
Couple of things.
Hogwash, older vehicles run just fine on 10% ethanol blend. Been running it in my '87 S10-Blazer for over 2 years now. The dealer is blowing smoke up yours. Mgiht be that way on highly tuned caddy engiens, bu the good old work horse 4.3L doesn't have that problem, especially on a '95. My '93 Astro van with a 4.3L only got feed 10% mix and I never changed the fuel filter. I had 286,000 miles on it before I totaled it one mornign on my way to work. Engine was as strong as the day I got it with 60,000 miles on it. Ethanol will clean out your fuel system, and yes it could be a partially plugged fuel filter. By the way, when was the last time you gave your truck a tune up? Air filter could be so plugged that your not getting a proper mix, it could also be a faulty O2 sensor. Defualt mode is to dump fuel, it runs, but like crap. PVC valve? Fuel pressure? spark plug gap, distriburator cap. Any and all of them combined will cuase all sorts of problems.
The best thing to do is check for any codes, and give it a tune up if it has been 3 years or more.
#16
06-13-2006 | 04:07 AM
RE: Update RE: Running REAL rough again....
No codes being published... I check it every couple of days, now just to make sure.
Oil changed last in mid-March of this year, Air filter changed at same time...
Fuel filter - changed appx 3-4 weeks ago (about a week after the current condition started).
O2 Sensor - Changed in late March of 2005. (so about 15 months ago)
Plugs changed in October of last year (8 months ago) - along with the spider kit & nut kit.
Wires changed in March 2004.
On my first tank of 10% Ethanol blend, I got right at 22 MPG - so I can't complain about the initial mileage... But that's gone down the tubes for now.
Thanks,
Rex
Oil changed last in mid-March of this year, Air filter changed at same time...
Fuel filter - changed appx 3-4 weeks ago (about a week after the current condition started).
O2 Sensor - Changed in late March of 2005. (so about 15 months ago)
Plugs changed in October of last year (8 months ago) - along with the spider kit & nut kit.
Wires changed in March 2004.
On my first tank of 10% Ethanol blend, I got right at 22 MPG - so I can't complain about the initial mileage... But that's gone down the tubes for now.
Thanks,
Rex
#17
06-14-2006 | 02:37 AM
BF Veteran
Joined: May 2005
Posts: 3,890
From: Central Illinois
RE: Update RE: Running REAL rough again....
Have you checked for a vacuum leak?
Look for a lose hose on the backside of the intake manifold. About where the distriburator cap is. Also check the air pump, and air pump valves. I haven't had to service them yet so I am unfamiliar with how to do it.
Look for a lose hose on the backside of the intake manifold. About where the distriburator cap is. Also check the air pump, and air pump valves. I haven't had to service them yet so I am unfamiliar with how to do it.
#18
06-14-2006 | 12:19 PM
Joined: Mar 2006
Posts: 142
From:
RE: Update RE: Running REAL rough again....
ORIGINAL: ShadowHawk
No codes being published... I check it every couple of days, now just to make sure.
Oil changed last in mid-March of this year, Air filter changed at same time...
Fuel filter - changed appx 3-4 weeks ago (about a week after the current condition started).
O2 Sensor - Changed in late March of 2005. (so about 15 months ago)
Plugs changed in October of last year (8 months ago) - along with the spider kit & nut kit.
Wires changed in March 2004.
On my first tank of 10% Ethanol blend, I got right at 22 MPG - so I can't complain about the initial mileage... But that's gone down the tubes for now.
Thanks,
Rex
No codes being published... I check it every couple of days, now just to make sure.
Oil changed last in mid-March of this year, Air filter changed at same time...
Fuel filter - changed appx 3-4 weeks ago (about a week after the current condition started).
O2 Sensor - Changed in late March of 2005. (so about 15 months ago)
Plugs changed in October of last year (8 months ago) - along with the spider kit & nut kit.
Wires changed in March 2004.
On my first tank of 10% Ethanol blend, I got right at 22 MPG - so I can't complain about the initial mileage... But that's gone down the tubes for now.
Thanks,
Rex
How about the CAP, ROTOR, WIRES, COIL. How old are they? Sometimes the obvious slips right by us. have you checked for leaking wires at night?
#19
06-25-2006 | 04:14 PM
RE: Update RE: Running REAL rough again....
Well, 2 days ago, I changed the PCV valve and the EGR valve. Still oily in the intake plenum... and the rough idle didn't change after I reset the computer (by disconnecting the battery for about an hour while performing the changeout of the EGR valve).
One thing I noticed, was that when I bought the EGR valve, Auto-Zone's computers had a note stating "LOCATE TEST CHART EGR1 IN WELLS TEST MANUAL" - Does anyone here have a copy or access to this manual? My Auto-Zone did not have it there for reference...
THis recirculation circuit has me a bit baffeled.. I understand how it works.. and what it does - on paper... but I'd like some direction on testing individual components without the expense of just buying new and replacing 'til it works.
Hose to back of manifold is intact - and was replaced about 15 mos. ago. All hoses that I have access to appear to be intact. THere's one hose from the MAP sensor that also goes WAY down to the back of the engine, but I lose track of it before I can see where it terminates - so I can't fully say that it's leak-free. Air pump? Unfamiliar with that...
Cap, rotor, coils & wires were all replaced about 2 years ago IIRC. I have run it at night with the hood up, but have not noticed any light or arcing from wires.
Thanks,
Rex S
One thing I noticed, was that when I bought the EGR valve, Auto-Zone's computers had a note stating "LOCATE TEST CHART EGR1 IN WELLS TEST MANUAL" - Does anyone here have a copy or access to this manual? My Auto-Zone did not have it there for reference...
THis recirculation circuit has me a bit baffeled.. I understand how it works.. and what it does - on paper... but I'd like some direction on testing individual components without the expense of just buying new and replacing 'til it works.
Have you checked for a vacuum leak?
Look for a lose hose on the backside of the intake manifold. About where the distriburator cap is. Also check the air pump, and air pump valves. I haven't had to service them yet so I am unfamiliar with how to do it.
Look for a lose hose on the backside of the intake manifold. About where the distriburator cap is. Also check the air pump, and air pump valves. I haven't had to service them yet so I am unfamiliar with how to do it.
Hey Rex...
How about the CAP, ROTOR, WIRES, COIL. How old are they? Sometimes the obvious slips right by us. have you checked for leaking wires at night?
How about the CAP, ROTOR, WIRES, COIL. How old are they? Sometimes the obvious slips right by us. have you checked for leaking wires at night?
Thanks,
Rex S
#20
06-25-2006 | 06:41 PM
Joined: Jun 2006
Posts: 89
From: http://teamrpm.org
RE: Update RE: Running REAL rough again....
just last week i noticed some of the same things and i drove to the video store and it was sure dumb luck that i looked under the frund wheel well and notaced a small arc caused by my spark plug wire poping off(not all the way off but like half way off) i took it home and let it cool down cuz its the one behind the stering shaft(same blazer you have) i pushed it all the way on and that solved the problem.
my blazer ran like that for almost a hole week and i tried almost everythign but that seemed to fix it i went ahead and checked the rest of the wires to be sure
you mite want to try that.
its simple but it fixed my problem
my blazer ran like that for almost a hole week and i tried almost everythign but that seemed to fix it i went ahead and checked the rest of the wires to be sure
you mite want to try that.
its simple but it fixed my problem