2001 Saturn 1.9L bucking under load
 

I have tried everything to correct this and have found almost all bucking under load stops when the EGR valve is electrically disconnected.
Does anyone know the proper way to check EGR Valve electrically?
$373.00 here in canada
Weid this is when I disconnect the EGR the Check Engine Light comes on.
When I reconnect it and clear the Check Engine Light I can fight to drive it at around 30km and after
3 or more starts the check engine light does not come on. Go figure!
No check engine light equals no codes to read.

Thanks
Calvin

Remove and clean EGR valve with carb/choke cleaner to remove carbon deposit buildup. Quite common for the S car engines due to oil consumption......be sure the pintle (center) moves freely -- be careful not to damage it.

Also be sure to clean the two ports where the EGR attaches.

Based on above descr, EGR solenoid sounds operational-- seems like the EGR pintle simply can't move to where it's being commanded to go. This will usually eventually throw a code as an EGR system fault -- but not always. Hence your lack of codes.

have checked
 

Have had it out a month agoand the pintle moves freely. Almost looks as if it has never seen dirt. Looked in through the large hole and there is soot but again pintle seems to move freely.
How far should it move in? Just mooving and moving propper distance.
Reconnected EGR this morning.
Early this morning I drove around the block the car worked so, so and then when temp got almost up to 1/4 mark the severe bucking started again. Got out and disconnected the EGR connector and have to leave it off for now to drive car. Power now is way down and it has to fight to get up smalll hill. Monday don't know if I will be able to drive it to work on the Highway.

Did your cleaning at that time rid you of this issue, or was the cleaning part of the ongoing saga we're discussing now?

EGR issues often do not show themselves until the gunk gets warm---its then that the sticking begins. For me, I would notice it on deceleration, as mine would stick open while the PCM wanted it closed. SOme electrical problems are similar and do not appear until components get warm.

Sounds like your EGR is sticking closed....so I understand why you'd suspect the EGR solenoid. . ...which also may begin to fail as it gets hotter....

1) does the unwanted performance occur in your driveway if you let the car heat up to operating temp? Meaning do you see strange RPM behavior in neutral if you rev the engine while in neutral while sitting still? The EGR should still try to open under such circumstances (acceleration)....so you should see the misbehavior likely in the form of RPM gyrations, especially when you let off the accelerator

With the car at operating temp, put a voltmeter on the EGR solenoid output. The output should be constant (DCV) when the RPMs are raised and then held -- if not, I suspect the solenoid is bad.

How much oil do you burn betw oil changes?
How many times have you cleaned this particular EGR valve?

I just got back from trying driveability again. With engine at operating temp there is no sign of the problem in the driveway. You would never know anything was wrong. When driving this time there was no bucking but when pressing pedal beyond 1/4 inch car bogged down inturn slowed down. When releasing pressure on gas pedal car spead up. There was no flucation on temp gague or tach except dropping in revs as car bogged down. Would not be able to drive on highway acting like this. Normaly when it would buck severley the tack was flying all over the place. To measure the voltage you mentioned what colour wire is it on the EGR connector? I did a test yesterday also to check fuel flow out of filter to engine and got approx 1 litre of fuel in approx 8sec. while cranking.
Car has roughly 44th miles on it and burns hallf a quart of oil between changes. I purchased it a year ago and at that time it had roughly 24th miles on it. Original owner had coil pack replaced. Over the time the previous owner had it, it was only used in the summer months by his wife. I have only cleaned the unit once and it did not clear the problem.
Though do not know how far the pin is suppose to travel.
Hope I have not left anything out. Dissapointed it did not buck this time but will try again later today so I can completly answer your questions.

RPM Gyrations are telltale sign of EGR not going where it's commanded to go. It is hanging up in a position where it shouldn't. The question of course is why.

Measure voltage across the wires coming out of the EGR solenoid -- don't know the colors used in 99. IF you can, hook up your DVM and secure the leads to the test points, then feed the leads under the lip of the hood by the windshield and attach to your DVM so that you can see the voltage changes while you drive. Make sure hood is latched appropriately. When you hit and hold the gas under load, I'd expect to see a steady DCV corresponding to commanding the EGR to stay open--though honestly I've never tried this myself.

Intermittency can be annoying as hell when going after these types of things.

Seems EGR can't go where it's commanded b/c
1) EGR Solenoid is flaking out
2) Coils inside the EGR itself are flaking out
3) The pintle movement is obstructed/improper......

Will check wire colors on my 97 SC2 and post....

Also recommend changing ECTS and connector on this vehicle--should help with bogging. Replace with BRass style OEM replacement. Connector is Dealer only.

For such low miles, sounds like someone needs to clean this puppy out on the highway once you solve all this.

This is a 2001 SC1 with the 5 wire I beleive EGR. No vacume lines.
I have a Haynes book but pictured and in the wiring drawing is the old EGR with the vacum lines and different coloured wires.

Sorry I meant SL1 in above reply. This auto is frustrating me. Can't wait till all this is over. Repaired I mean.

5 wire? Like you I have an older chilton manual for 1st gen saturns, so I will check my 97 later today and see if I can sort it out on mine.

I miss Low Saturn -- he has a full set of shop manuals for pretty much everything Saturn S Series

Update
 

Just removed the EGR again and recleaned it. Funny that first time I removed it the Pin port in the intake was almost clean. This time it looked somewhat like the exhust port. Reinstalled and took for drive.Cleaned the connector also and reset the PCM by removing its fuses for 2 min.
Result same as first. Low power and when temp gague hit the quarter mark severe bucking to the point it stalled.
I have just ordered a new EGR valve and will have to wait for it to arrive in 9 days to see what happens.

Calvin

Update
 

Changed ECTS and there was no change in the driveability.
Attempted to drive the car to work today and could not get
above 75KM per Hour. Had to turn around and go home to get wife's car
to get to work.

Changed EGR no change
 

Just installed new EGR Valve in 2001SL1. Car have been sitting for 2 days.
Went out for a drive and car seemed to work great. Temp guage reached around1/4 scale and when I touched the gas engine almost stalled. ried again with same result. Coasted to side of road and disconnected EGR valve. Started up ad went on my way. Car had reduced power and would not be able to be driven on highway due to sever bogging when gas pedal was depressed over 1/4.

Replaced so far:
Gas Filter
Sparkplugs
Sparlplug wires
Coolant temp sensor
EGR Valve

Tested
Maf Sensor Cold within spec.
Throttle position sensor. Within Spec.
Coils Within spec. (Cold)

Hope I have not forgot anything.
HELP!!!!!

Calvin

Update Codes
 

Just came from Garage. Mechanic had only limited time.
Car was put on computer and the only code showing was PO172a
FUEL TRIM RICH. Then he checked fuel pump pressure. 63LBS
This pressure is above the max 55 spec. There were no other codes.
I expected the O2 sensor readings to be outside the min max which would indicate to the computer MIX was too rich and it should lean out causing the problem I have.

Can Any Body Help Please? I hate to go back to the mechanic for he said it will take quite a time to figure this one out.

fuel pressure regulator?

Fuel Pressure regulator?
 

Just wondering? I thought the fuel pressure regulator was in
the fuel filter? If it is I have changed the fuel filter twice with no change in the way the car is working though I did not check the fuel pressure every time.

Am I correct or not?

Calvin