Burgundy&TanMan

EGR beig stuck open a lil bit can make it idle like its cammed, so egr could be some of the problem. I guess it could be stock manifolds leaking, they're terrible about breaking the heads of the bolts and I guess after a while it could leak past stock manifold gasket. If he has a scan tool he could check the long tem & short term fuel trims that can be some indication of what the ecu is trying to do. but yeah usually flashing check engine light means random misfire. One question when do it do this? certain RPM, when engine is cold?
all the time, just trying to get more info.

NLalexx

Ok guys.. so i took the truck to my tunner and he connected it and guess what... NO CODES and the engine check was blinking... the guy at the shop found a p1154 and we changed bank 2 1 O2 sensor and it got a little better but it still sounds wierd and smells like a lot of gas... plugs and wires were checeked and still the same.. it runs and my Stall wont lock up but as soon as e erases the check engine flashing it locks.. so i lean more into the electrical side than any mechanical thing... What do you all think help please

AKlowriderZ71

iTrader: (22)

Your guy helping you needs to do more than just check for codes. He needs to scan live data while the engine is running. A flashing check engine light means that you have catalyst damaging misfires. Your tune (most likely) has the misfire count tables set very high, and that's why the DTC's are not being set.

With HPT, EFI Live, or many other quality scan tools, a tech can moniter current misfires for all cylinders, and history misfires for all cylinders. That will narrow down which cylinder is the problem in your case, and then the troubleshooting can begin.

NLalexx

yhea bro all the time he checked and said all my sensors were working great and all fuel and ignition things looked great too... he mentioned that it could be a broken valve spring... too but i dont hear anything in my engine ...he checked for thaat too all cylinders everything great... no history codes... and yet check engine kept blinking and stoped at times... and came back minutes later ect... strong gas smell

NLalexx

he ran it and checked and said all the senors looked good and that fuel delivery was great too and ignition stuff... and also no codes.. the engine sounds kind of weak and its like boom boom boom boom ... not a solid tone as it was...

AKlowriderZ71

iTrader: (22)

I hope this helps. If your guy does this, you'll know which cylinder your problem is on. Of course, he'll still have to actually diagnose the problem....

Crisdg.KHP

Does any of the forum rules specify people are not allow to type words in Spanish?? I don't think so..

CalEditor@PCMCalibrators

iTrader: (4)

Flashing MIL

I think it had to be a percentage over the FTP standard (over the 1.5 time listed below) to cause a flashing light. This would include Misfires as listed below

IMPORTANT
For the misfire diagnostic only: If a sufficiently high rate of misfire is detected within a speedlload window which could result in catalyst damage, the MIL will flash continuously until the vehicle is no longer in such an operating condition. It will then remain on.

MISFIRE MONITORING
Requirements
Failure criteria for the misfire diagnostic includes the following:

1. A level of misfire sufficient to result in emission levels exceeding 1.5 times the FTP standard
2. A level of misfire sufficient to result in catalyst damage at the current operating condition (engine speed, load and coolant temperature)
3. A level of misfire sufficient to cause the vehicle to fail the California Inspection Maintenance (11M)test

Regulations require misfire monitoring under all positive speed and load conditions (defined as cruises, accels, and idle). The diagnostic must discriminate between single versus multiple cylinder misfiring. If a single cylinder misfires, the diagnostic must identify the specific cylinder and the conditions under which the misfire occurred. The control module records the amount of misfires using software functions known as accumulators. Current and history misfires are recorded for each cylinder. Do not use misfire information for diagnosis unless directed to do so by the service manual.

Both Current and History Misfire counts are viewed on Tech 2 Misfire Data List, under the Specific Engine Data Menu.

Under criteria 1 and 3 (above), a DTC will set and the malfunction indicator lamp (MIL) turns "on" when misfire is detected in a similar engine speed, load, and coolant temperature window for two consecutive trips. The MIL must also be turned "on" if there is a malfunction in two non-consecutive trips (not more than 80 trips apart) under similar engine speed, load, and coolant temperature conditions. If misfire is detected on two consecutive trips, the MIL will turn "on" regardless of engine speed, load, and coolant temperature.

Under criteria 2, the MIL must flash once per second if misfire is serious enough to result in catalyst damage. Catalyst damage can occur with misfire at high engine speeds and loads. Flashing the MIL is intended to discourage the driver from operating the vehicle in this condition (to ease off the throttle) before catalyst damage results. If criteria 2 has been met, the MIL must turn "on" within 200 engine revolutions of the onset of misfire. Further, the MIL must cease to flash and be steadily turned "on" when the vehicle is no longer in an operating condition where misfire will result in catalyst damage.

-NOTICE-"Similar engine speed" must be within 375 RPM, and calculated load must be within 10%.