My m50 is pinging. Running out of ideas.

[328ijunkie]

Throw a set of 19lb injectors in there. Obviously not the "best" choice but will add 15% more fuel or so (not doing the math) across the board and shut it up most likely. I see a lot of m50s ping on aftermarket chips at <full throttle as the timing map iirc is across the board while the fuel maps that are commonly modded are WOT only (don't quote me on that)

[ForcedFirebird]

Throw a set of 19lb injectors in there. Obviously not the "best" choice but will add 15% more fuel or so (not doing the math) across the board and shut it up most likely. I see a lot of m50s ping on aftermarket chips at <full throttle as the timing map iirc is across the board while the fuel maps that are commonly modded are WOT only (don't quote me on that)

He said it's a stock chip. And actually a lot of the chips I have read personally, don't have much done at all in part throttle.

[Ryann]

These cars are not chipped. I can't speak for Wishno but the Modis shows my mixture is stoich when the pinging is occurring. Also, I get no lean codes, or any codes for that matter.

[Wishno87]

Ordered a fuel pressure tester yesterday. My car has 260k on the body so it's possible my fuel pumps are not in the best condition. My car is a 87 325i so it has the dual pumps.

[digger]

its not clear if this pinging is a part throttle or WOT reading the first post.

[Wishno87]

its not clear if this pinging is a part throttle or WOT reading the first post.

Once it is warmed up it will ping if I go over 20% throttle in most situations.

[ForcedFirebird]

Have you tried using better fuel and noting the difference? My Ford v10 has a light rattle under light throttle and on the highway if I use 87 octane (specially when hauling) and doesn't if I use 91 or better (my old F150 4.6 did the same thing) once they started getting high in miles. This will at least give you an idea if it is in fact pre-detonation since it will lighten up with better fuel. If no change it may be something else.

[digger]

Once it is warmed up it will ping if I go over 20% throttle in most situations.

if its at low as 20% load i doubt its a lean AFR thing. you should be able to lean if off to point of missfire at low load on a low VE NA motor. IMO there is something in there that when combined with the 60C IAT are causing an issue. check plugs for heavy buildup put them back in, Seafoam it and then add new plugs (non fancy ones) after seafoaming and driving all the depsoits out.

[Ryann]

I run non-ethanol premium.

[Wishno87]

I have been running 91 in both of my m50 cars. I used to run 89 without any problems either but have been using 91 for a few years now.

Going to be tearing into the e34 tomorrow. Smoke test, knock sensors, intake gaskets, fuel filter, and air filter.

[ForcedFirebird]

if its at low as 20% load i doubt its a lean AFR thing. you should be able to lean if off to point of missfire at low load on a low VE NA motor. IMO there is something in there that when combined with the 60C IAT are causing an issue. check plugs for heavy buildup put them back in, Seafoam it and then add new plugs (non fancy ones) after seafoaming and driving all the depsoits out.

I agree 100%, but changing fuel and it making a difference is a dead giveaway.

I will also say that every BMW I have dyno'd, starting with the stock file, they always run extremely lean until 3000rpm or so, m20 and 24v alike. When I say lean, it's well into the 15's. If they don't ping on the dyno at WOT, find it difficult to believe it is ping with light throttle, and why my first hunch was vanos rattle.

[digger]

how many miles on the engine does it use oil?

[Wishno87]

My motor has about 130k and I don't typically need to add oil between changes.
The e34 has 109 and I may add 1/4 of a quart between changes.

[e30austin]

How's your oxygen sensor and coolant temp sensors?

[Wishno87]

02 has 50k and the coolent temp has 13x,xxx. Might still replace all of them just to be sure.