Where is the egr valve on a 3.4L olds 1993

That previa has a central engine, so all engine work requires you take out driver and or front passenger seat out.

The EGR placement is here >> http://www.autozone.com/autozone/repairguides/Toyota-Previa-1991-1997-Repair-Information/EMISSION-CONTROLS/Exhaust-Gas-Recirculation-System/_/P-0900c1528008a1d5

near the bottom of the page.
Good luck

A flat spot on acceleration could be low fuel pressure or a faulty throttle position sensor. Could also be a vac leak such as a faulty EGR valve.
Is the check engine light on ?

probly age--needs boiling out or jet ajust-------try fixin idle speed with screwdrivr---------cud be engine issue-like tuneup---inspect inside distributer cap for corrosion or worn plug wires---also egr valve mite be bad--------get vehicle scanned

Depending on type of engine, its usually on the back of the intake manifold near the firewall.

Sounds like it could be a faulty EGR Valve.Try this,get the car up to 55 mph and if the engine smoothes out then replace the EGR Valve.

The 3.1 litre has an electronic EGR valve. It should be on the passenger side towards the firewall. It looks like this...

http://www.autopartswarehouse.com/popup/?type=more&image=L2ltYWdlcy9wcm9kdWN0X2ltYWdlcy9pbWFnZXMvYWNfZGVsY28vYWMyMTQyMTI5LmpwZw==&title=QUMgRGVsY28gRUdSIFZhbHZl&text=QUMgREVMQ08gRUdSIFZBTFZFIC0tIEEgaGlnaCBxdWFsaXR5LCBPRSByZXBsYWNlbWVudCBFR1IgdmFsdmU7IFJlcGxhY2VzIE9FIG51bWJlciAxOTE4NzMxMS4=

Checkk the EGR system for the EGR valve should open when the engine gets to operating temperature. If not the engine will stall out

Your vehicle has an EGR valve attached to the intake manifold. About how to replace an EGR Valve, check this procedure...
Parts:
1. EGR Valve

Tools:
1. Scan Tool
2. 3/8 in. Drive Ratchet
3. Wrench
4. Socket Set

Steps:
Step 1 Locate the OBD-I or OBD-II data link connector (DLC). Refer to your vehicle owner’s manual for the specific location.
o Tip: The OBD-I data link connector is usually located in the engine compartment near the battery or the fuse box. The OBD-II connector (post 1995 cars) is usually located beneath the instument panel next to the steering column.

Step 2 Turn your key to the“ON” position. Do not start the engine.

Step 3 Plug your scan tool into the DLC and follow the manufacturer's steps to read the diagnostic trouble code. Codes between P0400-P0408 are generic trouble codes for the EGR system.
o Tip: The OBD-II diagnostic trouble code (DTC) is a 5 character alphanumeric code. The first digit is a letter that indicates the component group, the second digit is OBD mandated or manufacturer specfic, the third digit is a subgroup, and the fourth and fifth digits define the component and basic problem.

Step 4 To test the EGR valve: Remove the vacuum line to the valve and install a manual vacuum pump. Start the engine and apply vacuum to the valve. If the engine idle speed drops, the EGR valve is working. If the engine idle speed does not change, the EGR system is not working. Most engines will stall if you fully open the EGR valve while idling.
o Tip: Some vehicles are equipped with electronically controlled EGR valves. Use a scan tool to test these valves.

Step 5 Remove the vacuum line or electrical connector from the EGR valve.

Step 6 Remove the EGR mounting bolts. Remove the EGR valve.

Step 7 Using a new gasket, attach the new EGR valve with the original mounting bolts. Torque the bolts to the manufacturer's specifications.

Step 8 Reconnect the vacuum line or electrical connector.

Step 9 Erase any codes on the scan tool through the“delete” or“erase” command. Remove the scan tool.

Step 10 Road test your vehicle to verify the repair.
o Tip: If the check engine light returns, repeat the diagnostic process for additional DTCs or take your vehicle to a certified repair shop.

Check the RIGHT PART before to take off the parts. Its possible that you can find few TSB in your library or dealer about this LINK.

Hope helps.

check your timming, it sounds like its out of adj.

Hello, yes the problem could me related to a vacuum leak around the intake manifold or carburetor area. What technicians often do is listen for vacuum leaks or spray some carburetor cleaner spray (can) that you can get at an auto parts store around the rubber vacuum hoses to locate the leak. If the engine speeds up when your are spraying, you have located the leak.
The other problem that likely comes up is the EGR valve opening up too soon or when the engine revs and this causes the engine to cut out. You can block off the EGR valve to trouble shoot the problem. If blocking off the EGR valve solves your problem, then you know where the problem is.