Ran a code tester (KOER) test and the tester grabbed a few codes.

13R (RPM at idle out of range/low)
25R (Knock not sensed during Dynamic Response test)
33R (EGR valve fault/ not closing properly)
44R (Thermactor air system fault)
52O (Power steering pressure switch open)
73O (Insufficient Throttle Position change during Dynamic Response test)

The truck has a bad studder that shakes the whole truck while driving. I'm not sure where to begin to fix it. The egr valve is brand new and I don't know why the code 33r comes up...so I don't know. Also, How do you if a torque converter is going bad?

Here is what I have replaced:
Head gasket
New egr valve
New EVP sensor
New TP sensor
New O2 sensor
Checked timing w/ a timing light
new plugs, wires, cap, rotor
Checked for air leaks -- none

anybody have any suggestions as to where to begin to fix this problem.

 

check for bad or unhooked vaccum lines around the egr. that might take care of 13r and 33r. not sure what tranny this is but on my 4r70w, a simple fluid/filter change took care of my torque converter shudder... if that is your trouble. erase your codes, warm it up, chk codes again.

 

I beleive the last 2 codes, the 52 and 73, are appearing by mistake. During the KEOR test, you have to give it a quick wide open throttle and turn the steering wheel about half a turn. I only know this because it happened to me. Hope this helps.

 

Check your EVR, if the solenoid doesnt work, it wont get vacuum to the EGR. I had that code after replacing the EGR and EVP, and i replaced that after finding out there was no vacuum getting to the egr. The hanyes manual has a good description of how to check it.

 

Thanks for the suggestions...

Kc73, the tranny is a 4spd. Not sure the real name for it.

miked79928, Yeah think those last two codes are mistakes too...I will try KOER test again tomorrow...

thomadm...what kind of symptoms did your truck have and what made you change those two parts in the first place?

thanks again for responding, I really want to get this truck running right again. Keep the suggestions coming.

 

When is the shudder happening? In all gears? just in 3 and 4? Only when between 35 and 50 mph? When it is not moving?

 

The studder is happening between 1500 and 2000rpm mainly....The studder is really noticable in 4th gear and around 35 mph.

 

That sounds like torque convertor shudder. Try changing the fluid and give it a couple of weeks.

 

well im having a very similair problem as u r.. did the whole OBD test also and replaced many parts without fixing the problem.. soi decided to bring her down to the shop.. found a performance shop.. they did many tests and there thinking its the intake manifold leaking some where.. causing a vacuum leak.. my truck also has a high idle tho.. 1000 rpm.. and i get the same stumble as u.. the cost for them to replace the gasket is kinda high.. but if there pretty sure thats it.. then im willing to pay.. i'm gona get it done this week or next week hopfuly.. the owner is gone for a week.. if i can put up with it that long then ill do so.. if not i'll get one of his employees on it rite away.. if i havent solved the problem bye the time i get the gasket replaced i'll let ya no how it goes and if thats the problem.. but wut gets me.. i just read u replaced a head gasket?? so u had the manifold off them rite?? ok i think i just wrote all this for nothin.. haha

 

drive the truck about 35 mph, let off the throttle, then step back on it do not floor it if its the converter it will shutter every time, if servicing it dosent help , you will half to change the converter.

 

My convertor would only shutter part of the time between 35 and 55.
If it's the convertor push the brake just a little that will unlock the convertor.

 

Thanks for the suggestions, I going to change the fluid here pretty soon.

Trav460, the intake gasket is brand new, so I dont' think it is leaking...

 

could u please keep us updated if u figure out wuts wrong.
thanx

 

I will keep you guys updated....and I hope that I get this studder figured out....I want my truck back to the way it was!

 

Check your engine harness grounds. All these sensors probably share the same ground. Check for loose harness connectors and corrosion in them.