99 Blazer Acceleration Problems


LJP_GURU
05-29-2006, 10:27 AM
When I press on the gas pedal to accelerate at any speed it begins to sputter/jerk and very slowly (dangerously slow) gathers speed and sticks in a lower gear until I back of the gas. When I back of the gas it switches gears but then there is no power and it slows down. I have to floor it to get it to switch gears again to gain acceleration and then I have to repeat process to keep moving. It is burning a ton of fuel now and because it is in a lower gear more often it gets the temperature higher than normal.

I have

Changed the fuel filter (which was plugged so I installed new one)
Checked the fuel pressure from the pump and the return line (all was acceptable)
Checked the EGR Valve (little rusty but functioning fine)
Checked to see if there was any obvious disconnected hoses or electrical connections (none found)
And the problem remains. So I look for any additional suggestions from a good Samaritan who may have encountered someone else or have experience this problem themselves and would share some tips on how I could narrow down the problem. Thanks

LJP_GURU
05-29-2006, 01:14 PM
Could a plugged catalytic converter be the source of the problem and cause all the fore mentioned headaches?

kmacmmac
05-29-2006, 02:11 PM
I simply removed the converter (6 bolts) and took a long broom/handle wooden dowel and broke everything out of the inside of it. The rattling was driving me crazy but I had no performance problems prior or subsequent to the "gutting". It ran great for more than 2 years. I did get a SES indicator light shortly afterward. I removed the positive battery lead for 10 minutes and the computer reset itself after several miles of normal driving. I believe this problem of high speed shut down is something else and I'm not totally convinced it is the fuel pump. I'll keep you posted as I continue replacing and spending!! It's killing me that I can't figure this one out.

LJP_GURU
05-30-2006, 10:42 AM
I'm shocked that there are not many replies or response for this one as this seems to be a fairly common issue. Any way I will give you what I know to try and help the next person out. From reading some other threads here on this great forum I came across three common things to check when their is loss of power or hesitation at any speed. 1. Was check the fuel flow and pressures on delivery and return lines (Mine checked out fine) 2. Check the EGR valve (It was a little rusty but the valve worked fine) 3.Check the catalytic converter (Well this was my problem it was completely blocked!) I did not think the cat would cause all of the headaches I had with lack of performance. I had acceleration problems, shifting problems for the auto tranny and I had to get a second mortgage for fuel consumption.

I took the old cat off and inspected the inside and it was clear to see it was plugged and there was no or very little air flow going through it. I read on another thread by kmacmmac he had gutted his cat so I asked how he did this and I did the same (FYI I do not recommend or endorse gutting the catalytic converter as a permanent solution to drive around with as it is illegal in most states and provinces) had to say that I'm from the CMA university (cover my ass) incase someone thinks these discussions are gospel. Any way after inspecting and determining the cat was plugged I gutted and took a test drive. This was defiantly the bulk of my problem and most of the serious issues were gone. I am surprised I did not get a check engine light though until after I took the cat off. I will be replacing cat this weekend and hopefully all is back to normal.

corning_d3
05-31-2006, 01:46 AM
Try cleaning the mass airflow sensor. Go get a can of brake parts cleaner, disconnect the ground cable from the battery and remove the MAF from the intake duct and spray into both ends until clean. Take care not to spray the plastic part of the sensor or the connector. Also take care not to break the fine wires inside. Make sure it has dried completely before you fire it back up. While your at it, I recommend cleaning the throttle valve with the cleaner also. By the time it takes you to clean both, you can hook the battery back up and start it. Don't touch the gas until the idle has leveled out, then take it out for a test drive. I forgot to mention the TPS may be faulty but I'm bettin on a dirty MAF.

LJP_GURU
05-31-2006, 09:44 AM
Try cleaning the mass airflow sensor. Go get a can of brake parts cleaner, disconnect the ground cable from the battery and remove the MAF from the intake duct and spray into both ends until clean. Take care not to spray the plastic part of the sensor or the connector. Also take care not to break the fine wires inside. Make sure it has dried completely before you fire it back up. While your at it, I recommend cleaning the throttle valve with the cleaner also. By the time it takes you to clean both, you can hook the battery back up and start it. Don't touch the gas until the idle has leveled out, then take it out for a test drive. I forgot to mention the TPS may be faulty but I'm bettin on a dirty MAF.

Thanks I will clean these items in addition to installing some exhaust components on the weekend. Is there a suggested maintenance routine on sensors and stuff like that or is it a when a problem arises clean and trouble shoot approach?

Blazer_boy
05-31-2006, 01:49 PM
haven't had that problem with my 99 Blazer but it does switch gears quite a bit up there... I tend on mine to get into overdrive when I push the gas pedal to the floor :P

corning_d3
05-31-2006, 02:49 PM
There's always preventative maintainence that can be done to increase the life of some sensors. Use good fuel and a bottle of O2 sensor safe injector cleaner every week. Avoid giving or recieving jump starts, minimizing idle time, etc. Heat, vibration and fluids are a sensors #1 enemy. Also keep any mud or dirt off the oxygen sensors. They detect oxygen outside the exhaust pipe as well as inside.

jenmcgee79
12-13-2006, 04:52 PM
For future references: I just had this same problem on my 2002 Blazer. For a couple months now we have been smelling a hot smell, then my distributor went out. We had it replaced 2 x's and no fix on poor mileage and acceleration. I took it to GM, and a mechanic once again put a new distributor on it thinking it was a timing issue. Well that finally did help but didnt completely fix it. Come to find out our cat was plugged we could accelerate slowly but if you stomped it to the floor you could forget it. I had it replaced at a local muffler shop that has done the exhaust work on all my vehicles. IT NOW RUNS GREAT and only cost me $120 for parts and labor. They showed me my cat and it was plugged with metal shavings, chunks and anything else you can imagine. Oh and by the way, my truck had started throwing a MAF sensor code, it is now fine.

ZL1power69
12-13-2006, 06:05 PM
welcome to af. thanks for providing that info but this thread is more than 6 months old. please refrain from posting in older threads in the future.

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