rough running blazer

[dukducgoos]

my 95 blazer has a jerky miss. i've replaced plugs. wires, rotor, dist. cap. took it to a local mechanic to be checked, he replaced the egr valve[claimed it had the wrong part number on the old one] anyway it did'nt fix the problem. he told me he thought the computer could be the problem. the truck runs better with the egr unplugged, but it still has the jerky miss. the miss occurs when your at a steady speed only, if you accelerate it runs fine.when the egr is plugged in it misses alot more but runs ok when i accelerate. there is no check engine light coming on, so i'm stumped as to whats causing this problem. can anyone please help? do you think it is the computer? any ideas would be appreciated. its driving me crazy.

[way2rud]

I am having the same problem with my truck. Had it checked out today, possibly the cam shaft sensor but more than likely it is the fuel injection system. Repleaced the egr on Tuesday and it did not help any. I am going to put both in next weekend. Is your truck running rich, smell gas once in awhile or carboning around the exhaust tip?

[dukducgoos]

Originally Posted by way2rud

I am having the same problem with my truck. Had it checked out today, possibly the cam shaft sensor but more than likely it is the fuel injection system. Repleaced the egr on Tuesday and it did not help any. I am going to put both in next weekend. Is your truck running rich, smell gas once in awhile or carboning around the exhaust tip?

i don't think it is running rich and i don't smell gas. i'm getting about 16mpg all around driving.

[Mikado14]

Your description sounds as if the problem is ignition.

I would recheck my work.
1. Is the cap seated properly?
2. Are all the wires seated in the cap and on the plugs?
3. Are your wires not intertwined where you could be inductively coupling into another wire?

[BlazerLT]

Originally Posted by dukducgoos

my 95 blazer has a jerky miss. i've replaced plugs. wires, rotor, dist. cap. took it to a local mechanic to be checked, he replaced the egr valve[claimed it had the wrong part number on the old one] anyway it did'nt fix the problem. he told me he thought the computer could be the problem. the truck runs better with the egr unplugged, but it still has the jerky miss. the miss occurs when your at a steady speed only, if you accelerate it runs fine.when the egr is plugged in it misses alot more but runs ok when i accelerate. there is no check engine light coming on, so i'm stumped as to whats causing this problem. can anyone please help? do you think it is the computer? any ideas would be appreciated. its driving me crazy.

Remove the EGR and clean it with throttle body cleaner and reinstall it with a new gasket.

Doe sthe truck idle properly?

Does the truck not start all the time and will sometimes take extended cranking to get it to fire up?

Also, search the forums for CPI injector checking if you have the Orange Vortec plate on top of your engine.

[dukducgoos]

Originally Posted by Mikado14

Your description sounds as if the problem is ignition.

I would recheck my work.
1. Is the cap seated properly?
2. Are all the wires seated in the cap and on the plugs?
3. Are your wires not intertwined where you could be inductively coupling into another wire?

i haven't rechecked all of these because it was doing the same thing before i changed them. sometimes after the truck has been driven and shut down for a period of time it runs fine, but if it cools completely down, like overnight, it starts to miss and jerk again.

[dukducgoos]

Originally Posted by BlazerLT

Remove the EGR and clean it with throttle body cleaner and reinstall it with a new gasket.

Doe sthe truck idle properly?

Does the truck not start all the time and will sometimes take extended cranking to get it to fire up?

Also, search the forums for CPI injector checking if you have the Orange Vortec plate on top of your engine.

i'll try to clean the egr. the truck idles fine after it warms a little, sometimes cold the idle will flucuate 2-3 hundred rpms. it starts just fine though. it is the vortec motor. what is the process for checking the cpi injector?

[BlazerLT]

1.) Clean and reinstall your EGR valve with a new EGR gasket.

2.) Remove the IAC valve and clean it with throttle body cleaner, scrub it with a tooth brush and get rid of the carbon and rinse it again with the TB cleaner.

Reinstall and your idle problem should be fixed.

Also, consider doing a fuull tuneup if you haven't done so including:

Cap & Rotor
Spark Plugs
Air Filter
Fuel Filter
PCV Valve.

[dukducgoos]

Originally Posted by BlazerLT

1.) Clean and reinstall your EGR valve with a new EGR gasket.

2.) Remove the IAC valve and clean it with throttle body cleaner, scrub it with a tooth brush and get rid of the carbon and rinse it again with the TB cleaner.

Reinstall and your idle problem should be fixed.

Also, consider doing a fuull tuneup if you haven't done so including:

Cap & Rotor
Spark Plugs
Air Filter
Fuel Filter
PCV Valve.

i have changed all of those, no improvement. i'll try cleaning the egr. just don't think it will help since it still missed and jerked after the mechanic installed the new one. sometimes after the truck has been driven and shut down for a period of time it runs fine the next time i drive it.

[BlazerLT]

Read my whole reply.

I also said to clean the IAC valve.