Engine bogs when cruising.

[mooz]

Old vw hates when somebody repairs him. Yesterday welded my corrado body little,and after that its cuts in,when cruising. At WOT is all ok, and even if i drive for example with third and rpm-s are over 2000,then it is also ok. But when cruising with fourth in city, 1500 rpm,then its cuts in. Its not stable.

I removed my negative battery terminal when welding, but maybe i must removed positive? Maybe i damaged ecu?

Blue cts is ok, lambda is ok. rotor, plugs, distributor cap are new.

edit: its does this only when warmer, cold is ok. Blue cts is new, but for a try i changed temp sensor and still same.

[G60 Carat]

I have one ECU that does this. And in my case it's the ECU. It does everything else normal, but will not steady cruise, it has an SNS STG4 chip in it exact same as my good ECU in my car. So it works perfectly fine under any boost, and at idle. But like cruising on the highway on 110kph the car will stutter and shake horribly. If I go WOT or close the throttle for a second (touching either throttle switch), then it cruises again fine for 30seconds or so and then it starts stuttering again.


I think it happened when my O2 wires rubbed through and it damaged O2 circuitry in the ECU. So it's not impossible welding on the car body damaged the ECU.


I keep that old ECU it because it would still make a good Race ECU, you never hold maintenance throttle for more then 30 seconds in a road race or auto-x anyways.

[vdubCorrado]

Does it bog at continuous rpm all the time or only when its warmed up? May be a failing O2 sensor. Just unplug it and try driving it again. The O2 on a G60 grounds to the rear motor mount maybe there was an issue with the welding. The plug is actually bolted to the rear motor mount, the should run well with it unplugged but it will run rich. I would try this first

[mooz]

Seems that with cold engine,its okay. But when warm,then cuts and bogs on continious rpm-s. Later going to try at highway if it does same over 2000rpm continiusly.
I tried without 02,no change. Also did new wiring to temp sensors, still nothing-

Its almost exactly like g60 carat describes. Just havent tried if idle/wot switches affect it for some seconds.

[vdubCorrado]

If the O2 unplugging didn't change anything the I would say the ECU. The chip feeds long term safe fuel maps and when the car reaches operating temperature it initiates the m trim maps of old saved data gained and the s trim maps of new data coming in to adjust fuel. Sounds like when you stop primarily reading l trim your ECU isn't processing information correctly...

[mooz]

Today some longer drives and discovered that alos at WOT does this. Some less,but still does. I thought maybe spark plugs. Try to change them within coming days.

[mooz]

Problem solved. One of spark plugs were broken,this white part of a plug was cracked. Got temporary skoda 1.8 118kw TSI plugs, 60 000 driven Now need to buy new. Any suggestions about spark plugs?

[weejunGL]

Problem solved. One of spark plugs were broken,this white part of a plug was cracked. Got temporary skoda 1.8 118kw TSI plugs, 60 000 driven Now need to buy new. Any suggestions about spark plugs?

Bosch WR6DP0

or go down to 5 if its highy tuned

[G60 Carat]

See and I have the exact opposite approach. I use only Copper, not Platinum or Iridium. I keep spares around and change them more often. They cost like $5 for 4 online, and I change maybe 3 sets a summer.

I just use NGK BPR6ES (or BPR6EY), and when I order from an online place I usually order 3 sets and keep them on the shelf.

If I know I'm going to spraying lots of nitrous, I'll change them out for BPR7ES (one step colder). (edit: remember the numbers for colder vs hotter are different brand to brand, some the numbers go up some go down, research it first)


However if you on stock boost/stock chip, then platinum's will last longer.

[mooz]

Okey,thanks for information.

I have almost stock. Eaton M62 with stock chip etc.