im desperate.

[bataangpinoy]

im seriously about to blow my brains out, i gave up a road trip with some good friends to get this thing road legal and running for my event april 10th. 72 hours of straight labor to get it from a shell to car that should run. and it wont run. i can crank it, but it just wont fire.


so far:

replaced main relay
replaced fuel pump relay
reseated the plug for the injector harness
reseated the diagnostic plug
reseated the c101

checked grounds, all are clean and well connected.


still no fire.

no noise comes from fuel pump when cranking.
fuel pump is less than 2 years old, i replaced it with a new bosch unit when i got the car.

the DME i received in a parts trade has been opened by the PO and he is unsure of the condition.. hoping its just the DME and not something really major.

[KenC]

Is the main relay sending power while you're cranking?

[jlevie]

For the engine to run the following conditions must be met:

Power on DME pins:
27 Start Input
18 Un-switched Power input
37 Power Input from Main Relay

Ground on DME pins 2, 14, 19, 24

Timing data from the CPS on DME pins 47 & 48 from a rotating engine

To have spark power must be present at the coil positive and ground pulses
from the DME's pin 1 must reach the coil negative. Power to the coil is
controlled by the ignition switch via C101. When checking for spark, use the
output lead from the coil to eliminate the distributor, rotor and plug wires.

To have injector firing power must be present at each injector and ground
pulses from the DME's pin 16 (Bank1) and pin 17 (Bank2) must reach the
respective injector bank. Note that the injectors are wired as two banks of
three. With cylinder 1,3,5 being bank 1 and 2,4,6 being bank 2. Power to the
injectors is controlled by the main relay. Injector firing is best checked
with a noid light.

The fuel pump relay must have power on pin 86 (relay coil) from the main relay
output (pin 87) and power on pin 30. The DME will ground pin 85 to turn on the
relay and power the pump(s) via pin 87. Of the above, only the fuel pump power
is fused. So if the there's power at pin 87, but not at the pump, check fuse
11.

The main relay and DME pin 18 receive power from the smaller of the to wires
that connect to the battery's positive terminal. That wire incorporates an
in-line fuse. When the DME is presented with a start signal, it grounds the
main relay pin 85 and furnishes power to the fuel pump relay, injectors, and
DME.

Troubleshooting:

Disconnect the battery and the DME cable. Then:

1) Disconnect the coil negative and check continuity from that connector to
DME pin 1. Also verify that from DME pin 1 to ground is an open circuit.

2) Check the resistance across DME 47 & 48, which should be 500-560 ohms. If
the CPS is dismounted, the resistance can be seen to change from about 500 to
540-560 ohms when a ferrous object is brought to the face of the
sensor. Neither pin should be grounded.

3) Check for continuity from DME 36 to main relay 85 and from DME 3 to fuel
pump relay 85.

Reconnect the coil, remount the CPS (air gap should be 1mm), plug the
relays back in, reconnect the DME, and connect the battery. Then do the
following checks:

1) With the key off, verify that power is present at DME pin 18 and main relay
86 & 30.

2) With the key on, verify that power is present at DME pin 27 and pin
18. Power to pin 18 is from the main relay and there should be power to the
injectors and fuel pump relay.

3) With the key on, verify that no voltage is present at the DME grounds (2,
14, 19, 24).

4) Verify that power is present at the coil positive and at fuel pump relay
pin 30. Those get switched power from the ignition switch via C101.

The engine will start and run (if poorly) with only those connections to the
DME in place. The other signals from Cylinder ID, AFM, temp sensor, etc., are
necessary for proper operation. But they won't prevent the engine from firing.

IMPORTANT:

A power check means seeing a voltage within about a tenth of a volt of what
you measure across the battery terminals, which should be at least 12.6v on a
charged battery.

A continuity check means seeing less that 1 ohm of resistance.

An open circuit means seeing a resistance of at least 100k ohms.

A good quality auto-ranging digital multimeter will make these tests much
easier.

[NigelStu]

I had some similar issues after my swap.

http://www.r3vlimited.com/board/showthread.php?t=197833

OBC in the car? check C104 plug.

[bataangpinoy]

can someone provide the P/n for an i AFM?

and j, thanks for the detailed troubleshooting tips. i will go through it now.

[bataangpinoy]

i get no power at the fuel pump relay..

[bataangpinoy]

ICV buzzes with power on. its looking like a faulty CPS, which is kind of weird seeing that i ordered a new one.

[Gruelius]

check for continuity of cps and continuity of cps plug to ecu harness ( anything should indicate its fine)

[bataangpinoy]

stumper..

[F34R]

Where are you located OP? I could stop over and give you a hand if you are close.

[bataangpinoy]

the car is in new jersey. im in new rochelle, ny

[bataangpinoy]

got the car to run.

car used to start regardless of temp, but idle low (600).

off idle driving is very good, power is typical of an m20. but on idle, it wants to die. if it doesnt, it will drop to about 300 and then catch itself peg even at 600. more often than not however it will stall if i dont blip the gas..

for example: when coming to a stop at an off ramp. the car would bog down to 500 rpm and more often than not it would stall if i didnt blip the gas.

earlier in the day i changed the FPR and coolant temp sensor when it died on me the first time. i was able to start the car without the AFM connected and it made almost no change in RPM when i plugged back in, which is very confusing to me.

changed the cps with new, car started again. got it to the shop but symptom persisted, and then died at the shop.

cleaned icv, started and idled low, 600. died when i came back to it about 5 minutes later.

tried another afm but still didnt start, and this is where im at now.





tomorrow:
check the fusible link
check dist. cap
will check spark plugs for carbon and re-gap them
check orientation of the TPS
hunt for vac leaks..

[bataangpinoy]

power wire on the c101 (injector harness) was loose, and the pin would slide back and away from the chassis harness. this was causing quite a bit of trouble