The 15 Y/O Turbo M42 Build Thread (Now Holley EFI Terminator X Controlled)

[Dj Buttchug]

Usually a hard start while cranking is from voltage drop, either a weak battery or a starter circuit that is drawing a lot.

these are my thoughts as well but my whole charging system is brand new.
I went through all my grounds again triple checked everything.

Im still stumped

[LJ851]

Can you log voltage while you are cranking ?

[Dj Buttchug]

Can you log voltage while you are cranking ?

Yes. I will post a log.

I think Im chasing an invisible fuel/spark issue and the real problem is voltage during cranking.

No matter what I change fuel or time wise the problem still persists.

Could it be the way MS is wired into the car? The Diy pnp kit plugs directly into the oem harness so it would have to draw power the same way motronic would.

[Farbin Kaiber]

So, when are you gonna get over this m42 insanity?

[LJ851]

LOL, Farbin's excited.

[wazzu70]

Im thinking voltage during cranking as well as a culprit. If you make a log of trying to start we could potentially eliminate that as a cause.

Other thing Im thinking is cranking settings. When you bump start you bypass these.

[Dj Buttchug]

So, when are you gonna get over this m42 insanity?

lol NEVERRRR!!!!!

Im thinking voltage during cranking as well as a culprit. If you make a log of trying to start we could potentially eliminate that as a cause.

Other thing Im thinking is cranking settings. When you bump start you bypass these.

Yep another detail I should point out is that I dont see 14 volts until I raise the engine speed to say 11-1300 by stepping on the gas. The battery light is on until the revs are up so it can be just sitting there idling at like 800 and im @ like 9 volts lol

[LJ851]

lol NEVERRRR!!!!!



Yep another detail I should point out is that I dont see 14 volts until I raise the engine speed to say 11-1300 by stepping on the gas. The battery light is on until the revs are up so it can be just sitting there idling at like 800 and im @ like 9 volts lol

9 volts are not enough !

[wazzu70]

9 volts are not enough !

Truth, sounds like you found what to look into! Your voltage should not drop that low.

Is it 9V before you try and start it in the key on position, or does it drop that bad after engaging the starter?

Hopefully I get mine back up again this weekend so I can monitor the voltage during starting on mine.

Do you have a battery charger? Hook it up and then try and start it and see if that fixes it.

[wazzu70]

So, when are you gonna get over this m42 insanity?

Why would he do that? :)

[Dj Buttchug]

Truth, sounds like you found what to look into! Your voltage should not drop that low.

Is it 9V before you try and start it in the key on position, or does it drop that bad after engaging the starter?

Hopefully I get mine back up again this weekend so I can monitor the voltage during starting on mine.

Do you have a battery charger? Hook it up and then try and start it and see if that fixes it.

Im around 9v DURING cranking which seems low. In the key on engine off position im getting 12 consistent. It only drops that low when the starter is loading the system.
Ive been using jumper cables attached to a running car. It seems to start better when using these but its still not very good at all. The only way it actually works is when I bump start it.

[LJ851]

... so it can be just sitting there idling at like 800 and im @ like 9 volts lol

Im around 9v DURING cranking which seems low. It only drops that low when the starter is loading the system.

Which one is it chuggz ?

[Dj Buttchug]

it goes as follows:

1st start from cold (bump start or cranking start) voltage is low (around 9v) until engine speed reaches 1300 rpm or so. For example, I bump start down a hill, engine starts up and reaches 800 to 900 rpm. I push the clutch in and put car in neutral. keep in mind I havent touched the throttle at all yet. At this point charging system voltage is 9 maybe 10 at best. All my dash lights are on and the car is running.

THEN,
I blip the throttle and instantly 14v is reached and engine settles back to idle speed. The voltage never drops below 14v after the initial blip of throttle regardless of engine speed.

cranking voltage is 9v always no matter what.

sorry for the confusion.

[wazzu70]

So does it start and die, or does it never even get running when using the starter?

[Dj Buttchug]

So does it start and die, or does it never even get running when using the starter?

itll start and die using the starter sometimes. Which leads me to believe I still have cranking setting problems.

It always bump starts, so i guess thats better than nothing at all haha. Ill get it sorted out. been kind of paying more attention to the e34 lately.