All different kinds of M20 fun.

[nickskater09]

Okay, so recently I swapped a B25 into my eta E28 and it's developing some issues. Ever since I swapped it in, it's never wanted to idle properly. It always idles at about 600RPMs and I've assumed it's from a vacuum leak somewhere or another and kind of written it off.

Every time I start the car, I can drive about a half mile before it'll start choking up and try to stall. As long as I keep feathering the throttle and keeping it on, it'll eventually learn to drive and run properly till it's turned off again. I don't have an O2 sensor so I kinda attribute it to that.

Now here's where my most recent issue comes into play, it's started choking up randomly while driving. It won't want to run unless I lay it down to WOT and it'll run until I let off the gas, and it'll choke up again. Most of the time it'll seem to learn how to run after that and it'll go away temporarily then come back. It just seems like it's not supplying any fuel to the engine. I'm kinda feeling like it might be the AFM getting worse and worse but Id like to get other's input to see what it might be.

[AndrewBird]

Start by fixing the vacuum leaks and put in an o2 sensor. You can't diagnose something with multiple known problems.

[david2991]

Same issue and I put in a different AFM and fiddled with idle screw and it solved the issue for the most part. But what really has it running smooth is a 327 specific tuned chip. Check out sssquid.com, he is also on the forum here and the chip is the perfect last bit to your hybrid motor. Brings out the potential throughout the rpm range.

[nickskater09]

Same issue and I put in a different AFM and fiddled with idle screw and it solved the issue for the most part. But what really has it running smooth is a 327 specific tuned chip. Check out sssquid.com, he is also on the forum here and the chip is the perfect last bit to your hybrid motor. Brings out the potential throughout the rpm range.

I need to sort out my vacuum leaks and oil consumption before I get into making my engine prone to running harder. Thanks for the input though! I'll have to try a new AFM this week.

[jlevie]

Did you also swap in an M20B25 AFM, engine harness, and DME?

[nickskater09]

Did you also swap in an M20B25 AFM, engine harness, and DME?

Yessir I did.

[Quinthirty]

Yessir I did.

Isn't the O2 sensor part of that system to complete the loop?

[nickskater09]

All different kinds of M20 fun.

Isn't the O2 sensor part of that system to complete the loop?

I have a B25 O2 sensor but it isn't hooked up properly.

Update from this morning, I was messing with it and unplugged the AFM to see what happened and the engine seemed to run better so I'm going to try replacing the AFM and see what I get.

Afternoon update: swapped in a different DME and AFM. It's still acting up if not worse. I'm starting to worry that this is a wiring issue.

[E30_fiend]

Find someone who has a known good working 173 ecu. Swap that in and see if it helps or fixes your issue.


Taylor

[Quinthirty]

I have a B25 O2 sensor but it isn't hooked up properly.

Update from this morning, I was messing with it and unplugged the AFM to see what happened and the engine seemed to run better so I'm going to try replacing the AFM and see what I get.

Afternoon update: swapped in a different DME and AFM. It's still acting up if not worse. I'm starting to worry that this is a wiring issue.

Does it act the same, or differently when its cold? Is it more stable when freshly started and crappy when its warm?

[nickskater09]

[QUOTE=E30_fiend;3825756]Find someone who has a known good working 173 ecu. Swap that in and see if it helps or fixes your issue.

Taylor[/QUOTE

Putting a new DME in seemed to smooth it out.

Does it act the same, or differently when its cold? Is it more stable when freshly started and crappy when its warm?

It's smoothed out tonight, I'll have to see how it acts on the way to work tomorrow. When it did it, it would run fine when cold, get up to running temp and go probably two miles before acting up.

[AlphaE]

Fix the o2!!! It'll never learn fuel trims w/o know what the heck it's doin. It's likin peeing in the dark. You could be wizzing on your shoes but since you don't have a light you have no idea.

O2 sensor, smoke it for leaks. Don't waste time w other stuff till these are done.

Oil consumption?? Sounds like you have other issues too. Sorry dude.

[nickskater09]

Fix the o2!!! It'll never learn fuel trims w/o know what the heck it's doin. It's likin peeing in the dark. You could be wizzing on your shoes but since you don't have a light you have no idea.

O2 sensor, smoke it for leaks. Don't waste time w other stuff till these are done.

Oil consumption?? Sounds like you have other issues too. Sorry dude.

I know it has other issues, trust me. But it seems like most of the oil is getting sucked into the intake because its coated with oil in all the piping/AFM/filter.

[NeedaE30]

oil in the intake afm & air filter sounds like it could have bad piston rings, maybe a clogged oil return tube, maybe leaks in the cylinder head. have you done a compression and leak down test? might be a good idea. this is something i have not done yet to my e30 either.. it's good a practice that most people tend to overlook