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Discussion Starter · #1 ·
Hey,
I got a 76 280Z, just rebuilt the motor and am chasing the gremlins that made me rebuild. Before rebuild car just died-drove it to store, came back 1 hour later and wouldn't start-found no compression and rebuilt. Thought that a little previous info might help... Ok...Now it's rebuilt and back in, but won't run correctly.
What it's doing now:
1. won't start without the tailpipe taken loose unless you tow it behind another vehicle at speed (possible catalytic converter problem)
2. flooding the cylinders with gas (much black smoke,but only out the first three cylinders-back three plugs are wet)
3. won't idle at all
Here's what I know:
1. the electrical leads to injectors are pulsing.
2. it's getting fire to all six cylinders
3. it is in time
4. unplugging the water temperature sensor and plugging wires together does nothing (hint from Nissan Mechanic)

I don't know what to ask really...but is there something else that will make the injectors run so **** rich but only in 3 cylinders? I really need help cuz I don't want to have to take this to a shop and pay an arm and leg for them to put parts on for troubleshooting.

Oh and btw: what do the dropping resistors on the fuel injection system do?
 

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RE: Any Fuel Injection Experts?

Dropping resistor takes the voltage from 12V raw from the battery to 3V which is all the injectors can handle.
Most problems that people attribute to EFI are not at all EFI problems. Yours sounds suspiciously like a plugged Cat. Pull the Cat and replace it with a new one or a peice of pipe temporarily. If it then runs you have found your problem.
 

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RE: Any Fuel Injection Experts?

Check your fuel pressure. The regulator is the diaphragm looking device right in the center of your fuel rail. It is fed from front and rear, cylinders 1-3 & 4-6. It may be plugged on one side which would cause you to have excessive fuel pressure on that side which would lead to a rich condition. Normal pressure is 36.3 psi.
Didn't know '76's had catalytic converters. Is yours a California version? Otherwise, disconnect your exhaust pipe at the exhaust header and see if the car starts OK. If it does, this could also be part of your rich running condition - a partially blocked exhaust.
Are you sure you jumpered the engine temperature sensor and not the Thermotine valve? There are three sensors on your thermostat housing. The one-wire is for your temperature gauge. The smaller two-wire sensor is the engine temperature sensor and the larger two-wire sensor is the Thermotine switch.
Do you have a service manual? You're in a realm where it will pay for itself by your not having to buy just one of these sensors.
Phantom
 

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Discussion Starter · #4 ·
<b>RE: Exhaust</b>

Partially blocked exhaust has really already been established because before I loosened it from the manifold the car would not start unless we were towing it down the street. Afterwards, it would start with the key-it's just running like **** and fouling spark plugs faster than I can buy them! I am leaning towards the problem with the fuel pressure regulator. Just didn't think about the idea that it could be blocked on one side.
Thanks for the info, I will prolly be back asking more questions, but hopefully it will be to say Hey It's running!!!!
Thanks again.
 
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