[Razz]

Took out my car for the first time Saturday at the track. After 4 laps my gas pedal got stuck.. engine reved up to the rev limiter for maybe 5 seconds before I shut the engine off.

I tried to restart the engine and noticed that the fuel pump was running when I turned the ignition on without turning the engine. OK double relay is fried, indeed. The right side relay was shut closed.

So I changed the relay, now the car starts for 3 seconds or so and then shuts down. I have spark, fuel delivery is OK at the rail put I don't think I have enough psi. (Will have to check with gauge). The air flow meter seems to be working fine.

Could this have fried the fuel pump or the computer?

Did anybody experience the same problem?

Thank you for your help.

 

[Brendan_LS]

the 'start for 3 seconds then shut down' syndrome says that the car is simply running on the cold start injector, until that supply runs out, then stalls...no injection pulse

for starters I would ensure the grounding point on the passenger side valve cover (for the injection computer etc.) is good and tight. if its good, have a look at the fuse panel for blown fuses especially no. 12 and no. 20. If that's exhausted, try swapping the injection control unit relay with another...something may be amiss with the spare you've swapped in. ECU's dont typically fail, but it can happen.

The throttle stuck open in my GTV6 once, and it also blipped the limiter for some seconds before I shut it down...everything seemed ok in my case.

 

[161qv]

gday m8,
I know when my car is playing up it's always the plug on the dizzy (distributor)
I fixed it this a small ziptie.

 

[Razz]

Hi Brendan,

Are you talking about the small rectangular box inside the car with 2 plugs?

All grounds are OK, I have enough spark to light a cigar..

How's the weather in Vancouver? Montreal rain all week.

Thank you for your help.
Orazio

 

[Brendan_LS]

the box I think you are referring to in the passenger kick panel is the ignition advance module. The injection relay is a large dual relay in the engine compartment on the passenger side firewall. I think the 'dual relay' relay is controlled by a 'key operated relay' in the fuse box, and is supplied by fuse #12 ans #20 in the fuse box.

I would definitely check that the ground on the passenger valve cover is in tact...


weather in van...very wet

 

[Razz]

I checked all the grounds,OK
Ignition relay clicks when key is turned on
Fuse 12 and 20 OK

I also checked fuel psi at rail inlet 36 psi and at fuel regulator 0 psi

Checked cylinder compression all cylinders 50 lb/in2 more or less.

Dual relay is brand new from the box.

Not sure what my next step is, could it be my injectors are shot?

Thank you.
Orazio

 

[Jose I]

I highly doubt that all your injectors went bad at the same time.
I'm having the same issue with one of my milanos right this instant, starts then stalls. but it will run longer when i disconnect one of the injectors. I totally lost.
keep posting what you discover might be very helpful.

 

[Razz]

50 psi is definitly low for a cylinder compression, what should be the average value? 150 -175 psi.

Probably the cylinders got washed away with fuel.

 

[DOM!]

50 PSI is way low. Does it smell like raw gas out the pipe or really rich?

 

[slyalfa]

When you did the compression test did you hold the throttle open?

The start for a few sec the dies sounds like the flap switch is not working.

When the flap is not all the way closed it should click the relay and run the fuel pump.

Easy to test turn on the key switch and push open the flap you should hear the relay click and the fuel pump go.Let the flap close the relay should click off and the pump stop. When you crank it, it bypasses the flap switch to get things going.
Once the motor is running even at idle the flap stays open some so the pump keeps going. But if you say crash and the motor stops the flap will close and shut off fuel flow so you wont burn. At lest in theory.

 

[Razz]

No, the car does not smell like raw gas and it did not run rich.


I did not hold the throttle down or put any oil in the cylinders. That's my next step.

The AFM seems to work fine, when I turn the ignition, the relay clicks, the gas pump goes on the the flap opens up just enough. Engine runs for 3 sec and then shuts off.

Thank you for your help.
Orazio

 

[Brendan_LS]

checks from the FSM:
-ECU has power and ground? (probe connector using a multimeter)
-check that the combo-relay actually works by probing terminal 88y and 88d (fuel pump) and terminals 88z and 88b (injectors) with a meter. there should be 12V here when on or cranking. if not check fuses and or relay set.
-if so, be sure that the coolant temperature sensor is plugged in, and has some resistance value between its pins (can be 12kΩ(-10°c) to 3kΩ(20°c) when engine cold).
- be sure that the timing marks on the camshafts still line up with the crankshafts' TDC marking
- check distributor timing while cranking with timing light to ensure it has not moved
- re-check compression. any pressure lower than 100psi states there is a severe mechanical engine problem and it will not run.

 

[Razz]

ECU - OK
Dual Relay - OK
CTS - OK
Timing Marks - OK
Compression - OK Now

Is there a way to check some other signals from the AFM? I know it works with the fuel pump, when the ignition is on and I move the flap, the fuel pump goes on.

Could it be my distributor, coil or module? I have spark?

I think it's time I call my old italian man... he will probably make fun of me again.

 

[Jose I]

unless you replaced the double relay with a new or known working .... and I mean KNOWN working one as in tried in somebody's car running well, I'd try changing it.
If you read my post I'm having all sorts of issues similar to yours.
Some how the pulse to my injectors was all screwed up, even though the spark plugs were getting wet, my injectors were not pulsing correctly, and I've traced it back to the double relay, I don't know how, but it test as if it were working correctly but a injector pulse light tester says very different, the cold start injector pulses very strong and the other six injectors would pulse very weak, so I kept checking other things and cranking and checking and cranking ...... so on and so on, until I noticed that the injector side of the double relay was getting hot so I started checking injector pulse again and to my surprise Injectors stopped pulsing completely, So yay I guess at least now I know Why my cars not running.
Hope that helps

Jose I

 

[ToonRboy]

Razz,

Your story seems to have unrelated causal effect. Very simply, if it starts you have spark. So most likely a fuel system issue, which many times is an electrical fault, or component fault. This is not to say that it couldn't be ignition. If you were racing and as you say, it's raining, it's possible something got shorted by water.

Alfa Romeo 75 Milano v6 Service Manual | Free workshop, repair and service manual

Start on page 56.

 

[Razz]

Did another check run this week-end (my old man was busy starting is garden). I have definitly no pulse to the fuel injectors, I checked with the NOID lights. The dual relay is out of a box, brand new. Checked all the grounds all seems to be OK.

Is there an easy way to check the ECU?

OM

 

[slyalfa]

Do you get a good spark? The L-jet makes it pulse based on the pulse from the coil.
and are all the wires on the coil.

also the L-jet is very picky about voltage. if the voltage is low it will not fire the injectors. Is the voltage at the 13.8V? I think it stops working around 9-10V if the battery voltage is too low right after the start and the alternator did not boost it back up in the 1 or 2 sec run off the start injector. it will just die.

 

[Razz]

Yes, spark is good, voltage is around 13v.

I unplugged all the injector connectors, and with the key on I tested the voltage at the connectors,

12V on the red wire (from dual relay) and 7V on the wire coming from ECU. All six gave me the same result.

Shouldn’t the wires from the ECU give me 12V when the ignition is on? Or should it give me 12V when engine is running?

 

[Jose I]

12v with ignition on 0v with it off. check all you connections a coil and find another ECU, And sorry to bug you with the same question Is your double relay new after your incident or new from before incident?
sounds like a fubbed up ecu , even though it's very rare fore ecu to just quit on you like that most of the time you just get rough running vehicle.
Is you engine 3.0 or 2.5 If it's 2.5 I might be able to toss you one super cheap to get u going again.

 

[Razz]

My spare dual relay is new from the box. The one I had on the car was also new.

All my tests are leading me to a bad ECU, I'm trying to locate someone in Montreal that can test it but it's not easy to find.

My engine is a 2.5. Thank you for your offer, let me know what you have, if I can't find anyting locally I might take you on your offer.

Thank you.

Orazio