m20 still wont run (video inside)

[deutschman]

I didnt change the chip for a 19# tune. I read some where that the ECU would adapt to the 19#ers... Bull shit I guess. So I should get a chip a guess.
Ill do the wet spark plug test today.
I have tested all the spark plugs twice and I have spark on all of them.
I have not tested compression, how ever I really hope it is not a compression problem seeing as I just built this damn motor.

[Jaxx_]

starter sounds like it is getting the compression resistance.

I would spray some starter fluid in it to see if it fires better, at least then you'd know that the spark and timing is all good.

[deutschman]

starter sounds like it is getting the compression resistance.

I would spray some starter fluid in it to see if it fires better, at least then you'd know that the spark and timing is all good.

It does run for a while with starter spray. So you are right, it shouldn't be a timing and/or compression problem. If I keep adding starter spray while it is running I can keep it going till I run out of spray.
My bet is still on the injectors and a fuel problem of some kind.
Could it be a problem with the throttle position sensor?

[Cabriolet]

your car will start and run w/o the tps connected. it just wont accelerate smoothly or return to low idle.

[deutschman]

your car will start and run w/o the tps connected. it just wont accelerate smoothly or return to low idle.

So what is responsible for sensing the throttle and adding more fuel, because it seams like that is not happening.

I did the wet plug test and its weird. Plugs 1,2,3,4 are clean and dry and plugs 5,6 are black and wet. Whats up with that? I thought that they fire in 1,3,5 and 2,4,6 so why are 5,6 wet? I would have expected 4,6 or 3,5 to be wet if anything.
Just to keep this in mind the injectors all pasted the OHM test coming in at 15-14 OHMs, and the injector harness passed its electrical test as well. I am thinking it might be the ECU/CPU (what ever you want to call it) because when Kronus and I did the injector control test at the ECU it did not make any injectors click.

plug 1 (dry & clean)


plug 2 (dry & clean)


plug 3 (dry & clean)


plug 4 (dry & clean)


plug 5 (wet & black)


plug 6 (wet and black)



Any ideas?

[jlevie]

The idle switch in the TPS tells the DME that the throttle is open. The fuel flow is then determined by engine & intake temperature, AFM data, and engine speed. Once the DME switches to closed loop operation (~60C) data from the O2 sensor will be used to adjust fuel delivery to get to stoich operation. When the WOT switch in the TPS closes, O2 sensor data isn't used and AFM data is only used up to 4500rpm. After that the DME computes fuel needs strictly from temperature/speed maps.

[deutschman]

Should I try borrowing an ECU and seeing if it will run on that?

[kronus]

If only 5 and 6 are getting wet that would explain why it sounds like a 1-cylinder tractor from the 1930s. Have you checked continuity of the injector harness?

[deutschman]

If only 5 and 6 are getting wet that would explain why it sounds like a 1-cylinder tractor from the 1930s. Have you checked continuity of the injector harness?

Yep, it came back good. When I did the noid light check every plug on the harness got flashes which tells me that the harness is good otherwise only 5,6 would have flashed.
The injectors all have good OHMs so does that mean they are fault free? Could they still fail to open even if the resistance was good? Keep in mind they have been rebuilt professionally.
Is it possible that something in the ECU is fubar and is only firing 5,6?
Is there a sensor or other electrical issue other then the injector harness being bad that could cause this?

[jlevie]

The DME fires the injectors as two banks of three with the injectors for cylinders 1, 3, & 5 being bank 1 and injectors 2, 4, & 6 being bank 2. With plugs 5 & 6 both being fuel wet the DME is firing both banks. So if the other injectors aren't delivering fuel and the noid light showing firing pulses, the problem could be the injectors. Or it could be something else.

Pull the injectors, connect them to the fuel rail and harness, point them into a towel and watch while the engine cranks with coil disconnected. You will instantly know whether they are all delivering fuel and will be able to make a rough assessment of how even the fuel delivery is. Since raw fuel is going to be sprayed, have a fire extinguisher handy and be careful.

[deutschman]

The DME fires the injectors as two banks of three with the injectors for cylinders 1, 3, & 5 being bank 1 and injectors 2, 4, & 6 being bank 2. With plugs 5 & 6 both being fuel wet the DME is firing both banks. So if the other injectors aren't delivering fuel and the noid light showing firing pulses, the problem could be the injectors. Or it could be something else.

Pull the injectors, connect them to the fuel rail and harness, point them into a towel and watch while the engine cranks with coil disconnected. You will instantly know whether they are all delivering fuel and will be able to make a rough assessment of how even the fuel delivery is. Since raw fuel is going to be sprayed, have a fire extinguisher handy and be careful.

Ill try that. Thanks.

[deutschman]

Tested the injectors


6 leaks and sprays
5 leaks no spray
4 leaks no spray
3 no spray no leak
2 no spray no leak
1 no spray no leak

Have to send them back. Shop must have messed them up. They were working before I had them "rebuilt."

Anyone in the bay area have some injectors I can narrow or trade plus cash for?