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Discussion Starter #1
Hi everybody. I'm having a problem with my '80 and I'm hoping someone might have an idea.

After I run the engine for a while, it refuses to restart for long periods of time. Upto weeks at a time! Even after it cools down it won't start. Then one day, it will just start up and once it does, it runs great.

For some reason the fuel supply is being cut back or off completely. When I disconnect the fuel line before the filter, little to nothing is coming through it while the pump should be running. I have replaced the fuel pump and filter already. Someone else suggested vapor lock, so I moved and/or insulated the fuel lines as they come near the block.

If I manually feed gas into the manifold, the engine will spark and run for the few seconds worth of gas I give it. Then it stalls out and dies.

Could my fuel lines be that gummed up? Or is there an electrical switch or component that controls the pump/fuel supply that is malfunctioning?

This spring, I'm going to replace the auto-tranny with a 5-speed, and while I'm under there, I'm going to run new fuel lines and have the gas tank cleaned and serviced. Is there anything else I should consider checking while I've got it all apart?

And since I've got your attention, I'm looking for a sending unit for this car if anyone has one or knows where I might find one, please let me know.

Thanks everybody.
 

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Is this a fuel injected or carb engine?

Vapor lock can cause starting issues but the condition would not last more then a few hours.

First make sure the pump is working, the cars electrical system most likely has a safety relay that keeps the pump off unless the engine is running or cranking to start.

Disconnect the fuel line after the filter and jump-start the pump. If no fuel or the pump fails to run with power applied there is a problem. You can check the line by disconnecting both ends and blowing air through.
 

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Discussion Starter #3 (Edited)
This is a fuel injected 4M-E engine. I transplanted it out of my old '79 last spring, which is carbuerated, but I switched it over to the FI configuration for the '80. I broke the frame on the '79 and it is now just a parts car. It rusted through the frame at the sway bar mounts on both sides and broke loose one day about two years ago while I was out driving it....made an interesting drive home......

Anyway...the fuel pump is new, so I have faith that the problem isn't the pump itself.

Now for some more questions......Not being electrically savvy myself for the most part, what is the best way to jump start the pump? And if it has a safety relay, where might that be located and how do I check it?

Thanks for the quick response, too, by the way. I really appreciate it.
 

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Cressida nut
91 Pickup (Hilux)2wd
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4,586 Posts
if you know the pumps new, I'd say the fuel lines are rotted and blocked or kicked/smashed somewhere. start by tracing and probably replacing them from the pump to the engine.
 

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RA28 + MX73
RA28, MX73
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Can you hear the pump?
If not, then it is more likely a bad ground to the pump or a bad ground to the fuel pump relay.
Corrosion and dirt can break the circuit.
A little flexing of the body and the circuit is connected again - until the next bit of flexing.

Get a wiring diagram and a circuit tester (just a light bulb and a metal probe) and start probing.

If you can't find a Cressida wiring diagram then use a Mark I Supra wiring diagram.
Alternatively, here are some wiring diagrams for the model after yours - they are similar for the fuel pump wiring:
http://members.iinet.net.au/~stepho/cressprd.htm#cressida1980pr

- Stepho
 

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Check coolant thermosensor, if it "opens" inside, the engine will be flooded.Had this problem with my 1979 Supra, back in 1992.
To prime the pump:Open the yellow connector near the AFM, and short the terminals with wire. with ignition ON the pump must run.
 
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