Running rough then stalls

[garretthes]

This car sat up for a couple of years. I replaced the plugs, wires, cap, rotor, cleaned injectors. I am getting good spark at the plugs.

We had it running well several weeks ago. Since then I had to replace the clutch slave/brakes so I could finally drive it. Not it runs like crap.

When I hit the starter it fires right up and runs OK for a minute then gets worse then dies. Then it will not start

The following systems have been ohmed out and are within spec.

Idle Throttle Switch-OK

Full Throttle Switch-OK

Air Flow Meter Resistance-OK

Air Temperature Resistance Sensor-OK

Water Temperature Sensor Resistance-OK

Air Regulator and Fuel Pump Circuit-OK

ECU grounds (4)-OK

I also cleaned all the electrical connectors.

I'm wondering if the cat might be blocked up. Is there a way to check that without removing it?

[240260280z]

Probably the fuel is varnished. Drain the tank and see what comes out. (There is a drain plug in the bottom of the tank).

It could also be rust clogging the lines. Put a frame fuel filter before the pump on the low pressure side to monitor.

http://atlanticz.ca/zclub/techtips/fuel/g3filter/index.htm

[garretthes]

We drained the fuel when we replaced the pump. The filter is also new. Good call though

[240260280z]

Hmmm seems like it is still fuel.... but with your exhaust query. Can you start and rev and see what comes out the tail pipe?

What do the plugs look like? If the ECU was not metering the fuel correctly, your plugs could be pitch black and fouled to hell. Usually the culprit is the wiring to the temp sensor that resides in the thermostat housing. Connections at this sensor and ~ 1 foot back into the harness are where to check.

http://atlanticz.ca/zclub/techtips/runningrich/index.html

[garretthes]

Hmmm seems like it is still fuel.... but with your exhaust query. Can you start and rev and see what comes out the tail pipe?

What do the plugs look like? If the ECU was not metering the fuel correctly, your plugs could be pitch black and fouled to hell. Usually the culprit is the wiring to the temp sensor that resides in the thermostat housing. Connections at this sensor and ~ 1 foot back into the harness are where to check.

http://atlanticz.ca/zclub/techtips/runningrich/index.html

I will pull the plugs and clean them. They are black from excessive fuel. The last problem I had was white smoke and waaaaay too much fuel. It was coming out the tail pipe. I fixed that (Not sure how). I have been going through and cleaning all the connections including the temp sensor connectors and that helped.

When I crank it it runs fine and blows exhaust. I will get back to you after I clean the plugs off then run it again.

[garretthes]

Cleaned the plugs with wire brush and replaced them. Started the car. It ran OK for a few seconds then started to miss again. After about 30 seconds it worsened and wouldn't rev without bogging and detonation. I should mention that #1 injector stopped working. This sucks because it was working after I went through the fuel rail months ago.

Anyway, I ran the car about a minute, shut it down and pulled 2 plugs and they were black and damp. Smelled like gas.

I should also mention this car doesn't leak a drop of oil or anything else and when we had it running a few weeks ago it didn't smoke at all.

[garretthes]

I forgot to mention I did the screwdriver to ear method of checking the injectors. They all are pulsing except #1 as mentioned. #1 is closed. That plug was clean

[240260280z]

Yeah I had seen this before. Your EFI system is dumping too much fuel into the engine and your car is bogging because of the plug fouling.

You have to make sure the connectors to the temperature sensors are making good contact and that the correct sensor is used (there are a few in the thermostat housing. This is the usual problem that causes your symptoms.

Be sure to clean the plugs carefully, especially deep in the space between the insulator and threaded body.

[240260280z]

You can swap the EFI connectors from injector 2 with injector 1 to see if the problem is actually the injector or back in the harness/ecu.

If it is the injector: You can tap on the #1 injector to try and loosen it with percussion energy. You can also connect a 9V battery to a spare injector connector then push it on and remove from the injector to hit it with a high current. Just hold on for ~ 1 sec then remove as the high current will heat the windings if left on too long.

[240260280z]

btw I can't remember when Nissan moved the temp sensor to the back of the cylinder head next to plug #6. I think it was in 80 or 81 after the P79 came into existence.

If you can't find it in the thermostat housing then check the head.

[garretthes]

Also, I removed the starter wire and had someone turn the key to start. I could hear the fuel pump but I could not here anything from the fuel pressure regulator. Is it possible it is stopped up and letting the pressure get too high?

[garretthes]

Went through and found a missed connector to clean. The thermotime connector was pretty corroded. I cleaned it and also replaced the coolant temp sensor with the same part from the parts car because the wire was suspect. It was frayed were it touches the sensor and corroded.

Started it up...it ran pretty good for a minute then the same thing....ran terrible. Wouldn't rev without detonation or backfiring in the intake. Something is happening after 20 0r 30 seconds to make it crap out.