Major timing corrections, super knock & misfires

Msport335

Specialist
Jun 7, 2018
74
Having engine mounts checked tomorrow... could possibly be the cause of all the timing corrections. Most definitely seems to be the cause of the broken aluminum charge pipe
 
  • 1Wow
Reactions: Jeffman

Msport335

Specialist
Jun 7, 2018
74
couple updates on the car and things i've replaced still trying to decipher what's causing all the timing correction on high power maps...

New oem HPFP & engine mounts

I thought the mounts were completely gone as my ER charge pipe snapped off at the throttle body c clip so i figured there was more engine movement then there should be. Car definitely feels tighter and planted with the new mounts but I don't think it was the underlying issue to timing corrections on the ethanol or meth maps.

Below are a couple logs of the 94 pump gas map with the new HPFP .....car seems to be happier on the Pump only map in terms of corrections but this brand new HPFP doesn't give me as much psi in comparison to the one it replaced ....any idea why this would be? old one never dipped below 2000psi ....new one dips as low as 1300psi during the 3-4 shift


https://datazap.me/u/msport335/94-octane-v8x1-stock-knock-tables-1?log=0&data=3-21-22- old logs with old HPFP

https://datazap.me/u/msport335/94-pump-v8x1?log=0&data=3-21-22. - todays logs with NEW HPFP
 

typedRew

Sergeant
Feb 25, 2019
398
just because its new doesnt mean its better. go back to the old one and send that one back to fcp and get a replacement to keep as a spare. old one worked just fine

How new are your engine grounds?
 

Msport335

Specialist
Jun 7, 2018
74
just because its new doesnt mean its better. go back to the old one and send that one back to fcp and get a replacement to keep as a spare. old one worked just fine

How new are your engine grounds?
Engine grounds are all good... crimped and tightened as they should be. Those major timing corrections only seem to happen on high powered maps under load in 3rd/4th gear . Now leaning towards it being something in the auto trans which doesn't like all the added tq from those maps ..... i really don't know anymore.
 

Jeffman

Captain
Jan 7, 2017
1,436
No codes?
Since your AFRs, timing, boost, torque Lim active all look good, it would seem more likely to me to be an electrical issue - somewhere between your spark plugs, ignition coils, and ground...
1) Unplug all of your coils and carefully inspect - I once had a faulty PR coil connector that caused misfires and massive timing corrections.
2) Remove all your plugs, inspect and gap to 0.20 mil.
3) Clean the head where the plugs are seated. Lint free paper towel wrapped around a screw driver head soaked in WD40 or similar worked for me.
3) Reinstall plugs with dielectric grease on the ceramic insulators. Torque properly. Wait. Torque again! I also had loose spark plugs (Step one colder NGKs with aluminum rings were torqued, but loosened on their own.) Maybe replace with two step colder NGKs which have the copper rings and deform better to the head when torqued.
 
  • 1Like
Reactions: NoQuarter

Msport335

Specialist
Jun 7, 2018
74
no codes..just the usual 2aaf.
plugs are brand new 2 step colder ngk's gapped to .018 and were carefully inspected and torqued numerous times.
coils are brand new eldors...no issues with any pins of wires....grounds are all checked. even tried a different set of coils and same outcome.
The car is making power and engine runs smooth...no knocking...oil is clean, done 3 changes in the past 1500kms....ran 5.9sec 100-200 with all these corrections.

I honestly don't know where to look next
 

fmorelli

Major General
Staff member
Aug 11, 2017
3,077
Virginia
Clean the head where the plugs are seated. Lint free paper towel wrapped around a screw driver head soaked in WD40 or similar worked for me.
Call me paranoid but I think everyone should be inspecting the spark plug shafts and cleaning them thoroughly on any plug change. I would not run crush-once aluminum washer spark plugs either, if they come out and need to go back in - the crush washer is used up. One of the reason I went to the 2 step colder plug (NGK 97506) that hard the copper washer. Note the often suggested one-step colder NGK 95770 has the aluminum crush washer.

If I could offer an alternative cleaning approach to @Jeffman's. I tear paper towels into approx 2" x 2" pieces. Soak with brake cleaner. Then use a grab tool - bunch the center of the paper towel and clasp. If you don't own that General grab tool, you will thank me when you've spent the mere $10 and used it the first time. Built-in LED light too. Invaluable. Anyway clean the land area first (where the washer sits) thoroughly. Throw away scrap pieces of paper as they get dirty. When the land is clean, now run a fresh piece of wetted paper into the threads and gently turn to clean the threads. You can run the paper into the chamber and twist your way back out. If the paper falls in, not end of the world - will just burn up and exit the exhaust. Across six cylinders you'll spend 20 minutes cleaning. Time well spent in my opinion.

This ensures that when you torque the spark plug you actually are correctly torqued (with debris you are not) which will prevent plugs backing out or sealing issues. Second with a correct crush washer (not reused aluminum one-use) you will also have proper sealing and torque.

Filippo
 
Last edited:

Msport335

Specialist
Jun 7, 2018
74
Knock sensors are in the correct locations. I can always try to replace them but I dont think that's the issue. Haven't got any codes since hpfp was replaced
 

Similar threads


Top