injecter pulse???

Bill Hincher · Post by **Bill Hincher** » Fri Aug 15, 2008 10:39 pm

always make sure to have a good ground between the engine and the frame and from the frame to the body and from the body to the ECU, that is 50% of the electrical system

75COLT · Post by **75COLT** » Fri Aug 15, 2008 11:36 pm

Bill means you need a ground cable from the body to the chasis to the battery negitive to begin. Then the engine ecu has to have a good ground to follow. If you verify these, then check the power side of the components I.e engine ecu power,fuel pump, injector pulse. Do you have a factory service manual for your year engine and ecu?

Ian

jeffball610 · Post by **jeffball610** » Sat Aug 16, 2008 5:29 pm

So are you saying that the fuel rail runs out of fuel when you try to run it? Have you verified proper fuel pressure?

Also, there may be an issue with the injector harness somewhere. I had an issue where the connectors on the injectors were not giving the proper signal to the injectors to fire. I replaced the connectors with some spare ones I had, and presto, it ran just fine. The engine would actually idle somewhat running on only 2 injectors.

You might also check your cam angle sensor and make sure it's sitting properly and giving enough spark advance to keep the engine running.

Also, do you have some sort of data logger? This is a must for anyone with a DSM or 4G63 powered car. It's a simple program you can run on a palm pilot and you can read all the sensor parameters and check engine codes. The most used program is MMCD. If you do not have a logger, I suggest you do not try to start the motor or do any tuning until you have access to one.

http://mmcdlogger.sourceforge.net/

75COLT · Post by **75COLT** » Sat Aug 16, 2008 9:19 pm

Travis, 02 sensor is a key element to running correctly. Without it's signal the ecu will operate a pre-determined value which is usually full rich meaning more fuel. Have you verified all the other things that have been recommended? Jeff had some great answers for you in his post. I recommend doing alot of those checks to get this thing going.

Ian

Bill Hincher · Post by **Bill Hincher** » Mon Aug 18, 2008 11:53 am

lets see some pic's or a diagram of how you wired the injectors Travis, lets see what you are doing.

Fuel+ spark= fire dont get burned !

the injectors should have voltage on one side of all the connectors, when the ECU grounds the other side of the injector, it opens the fuel to the cylinder
so you should have steady flow of power to one side of the injectors with the key in the ' on' position

jeffball610 · Post by **jeffball610** » Mon Aug 18, 2008 5:29 pm

It is possible to flood the engine, but not probable. The stock fuel pressure regulator cannot handle all the fuel you give it from the Walboro 255, but it will still run well enough to diagnose other issues.

Now that you mention the O2 sensor, that could be an issue. You can read its voltage readings with a datalogger or even a volt meter. The Mitsu O2 sensor is kinda dumb in the sense that there are 2 wires that are the same color, so it might be difficult to wire up. However, I believe both are ground wires and it doesn't matter which goes where. The other two are for heating the sensor on startup and one for the ECU to read the voltage. (between .00 and 1.0v)

You may be able to check your injector wires to see if they are firing by plugging a volt meter or similar device into the connector and turning the cam angle sensor by hand or with a drill. This will tell you if the injectors are firing at the connector. The ECU will tell you they're firing even if the signal is not reaching the injector.

Even if the connectors look good, they may not be. The set I switched out seemed fine and 2 of the 4 were not getting a signal at all from the ECU even when the ECU said they were firing. The car ran and even drove some with only 2 cylinders firing.

If the injectors seem fine (wet plugs) then you might have an issue with your ignition coil. Easy test is to spin the CAS (cam angle sensor) by hand and see if you get spark at the coil or at the end of the plug wire.

From here we can determine if your system is working properly and if there is an issue somewhere else, or if one or more of the systems is not working and needs repair.

Bill Hincher · Post by **Bill Hincher** » Tue Aug 19, 2008 9:56 am

if you have 100 psi from the fuel pump, your return line isnt working, probably blocked at the regulator
but that pump is just pushing against a brick wall

jeffball610 · Post by **jeffball610** » Tue Aug 19, 2008 5:00 pm

I'm not sure what fuel cell you're running and how the fuel pump goes in, but most (if not all) of the Walboro pumps come with a little screen attached to the pump. This is your pre-filter. You will also want a secondary filter before your fuel rail. Also, in case you're confused, the fuel pressure regulator is at the end of your fuel rail leading to the return line.

Some guys that are not used to fuel injection (carb guys) and don't run return fuel lines. This is a necessary item in our cars. Although, some car manufacturers are running returnless fuel systems and direct fuel port systems that do not require return lines.