Idle Surge (At idle & During Acceleration)
I need little help on this vehicle here today. Vehicle came to me from a different repair shop with customer concern that Idle is surging or fluctuating while at idle or driving.
I have replaced Throttle Body, USED ECM and Update and tried learning idle several time with Snap On, Autel & OE HDS scan tool but its not learning at all. Its keep on showing on graph that its switching between "Not Completed to Learning" but never learns for some reason.
Fuel trips are switching between positive & negative 6. And I checked for leaks on cold engine and visually inspected everything properly but didn't not find anything wrong either.
I would look at was is causing surge at cruise first .
After you do throttle position relearn next be patient and let it idle all loads off at least 20min. assuming there is no other issues. monitor live data pid idle learn status after at least 20min of idling all loads off will switch to learned
Hello Luis. I let the vehicle idle for almost more than 2 hours and also took it for drive couple of times and I have been doing this for almost a week now. Still having bad luck :(
With HDS did you do the following tripple check there is no vacuum leaks. Select TP POSITION CHECK, in the inspection menu and clear the throttle position learned value. 3. Turn off the ignition, then, turn it back on. 4. Reset the ECM/PCM. 5. Do the idle learn by letting it idle surging while driving I would check egr live data pids and brake switch. did the engine or head get recently…
I WOULD PULL egr of and check . not un common for valve to get junk stuck in it .ecm can not do idle relearn if ecm does not like something. go back to basics what is causing the cruise surge ?????
Hello Luis. I have checked everything for leak on cold engine and very closely but did not find any leak. - this vehicle came from a body shop because customer had accident on driver side. Body shop have repaired everything but I'm not even sure if problem was before the accident happened or vehicle started doing this after the accident & I decided to call the body shop who performed…
Also; Saw one with a loose / broken air-box driving the MAF crazy due to non-steady air stream. Double check that the air-filter actually fits correctly and tightly in the air-box.
Hello. Geoff. I have checked to make sure filter is properly installed and sealed properly with clips on proper position.
Make sure no air pockets in coolant, iac valve not sticking, ect functioning correctly, good coolant flow through iac.
Graph ect . I think in fuel management . Surge at cruise????
Hello Benjamin. I have checked everything and there is no air in coolant & Already replaced ECT (OEM Part) and flow is good. I'll check EGR valve and see if I notice anything.
I have checked more than 5 times on cold engine and did not find any.
Do you have access to a scope to post a cranking compression test. what is map sensor reading
Hello Luis. I checked the MAP reading and its around 0.8V at idle. Thats what I'll do next to see if I have a compression issue.
I had 2 of these that idled too fast to complete the idle learn. Much like a Nissan, I had to force a misfire and perform the learn. Once complete, fix the miss and clear the codes. I can't remember if those cars surged at cruise, but might be worth a shot.
Hello Scott. I tried to create a misfire also to see if it learn but still no help.