Aw crap, where do I start? Engine problems..

[2damslow]

My 94 4runner lurches like it has ignition problems. It only happens when it's cold though, as soon as I drive it a bit it runs great.
Check engine light is now on.

Where can I get a code reader? Is there any specific type I should avoid?

 

[KLF]

The only code reader you need is a paper clip. Read this:

http://www.off-road.com/toyota/tech/codes/

 

[Grim Reaper]

You need to start by getting a shop manual. Even a Cheap Haynes would help.

 

["N8"]

The hayns or chiltons will narow it down but for starters ide look into the o2 sensor or the mass air flow sensor.

 

[2damslow]

My truck shows a code 71. I have already taken the EGR off and cleaned it. I applied vacuum to it and it operates freely. I think I need to test out that little pigtail sensor on the EGR body.
After that I plan to put a high flow cat on and run the sucker.
Keep the ideas comin...

 

[Chartdog]

If you are going to keep the truck for a while spend the $$ and get the Toyota FSM. You will use it again and again and it will save much frustration. IMHO the others are not detailed enough.

Not sure about Utah smog but when I tried a high flow cat my rig failed smog. It was very hard to get the cat hot enough to do it's job. Plus it made very little difference in performance.

 

[WristPin]

My truck shows a code 71. I have already taken the EGR off and cleaned it. I applied vacuum to it and it operates freely. I think I need to test out that little pigtail sensor on the EGR body.
After that I plan to put a high flow cat on and run the sucker.
Keep the ideas comin...

egr gasket could be leaking. you could have a vacuum hose disconnected. your cat could be clogged and that whould cause an exasust leak. a faulty O2 can cause the egr valve to over-work, and may stay stuck open. but likely would see a code for an O2. take it to an exhast shop and get a back pressure test and smoke test done, intake and exhaust. make sure your shop uses nitrogen, NOT shop air.

aside from the specific code data, be sure your ground strap on the plenum to manifold bolt is secure and clean.

you can use a handheld vacuum pump, to acuate the egr valve directly. you should hear the diaphram 'pop' open and close. the actuator valve must function too. it has three ports, one from the electronic solenoid, acts as the 'valve switch'. the other two are in and out , which is opened and close by the 'valve switch'