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I'll try to get that relay replaced soon. Hopefully that helps resolve my issue. It would be pretty ironic if I spent all this money fixing other things when the real issue was a bad relay.

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Swap it out with one of the known working relays. It will save you ten bucks and a trip to the parts store, if the relay is still good.

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I swapped a few relays around and didn't see any change. I also tried once without any relay plugged into the fuel pump and saw no difference. The car has still not failed to start but has been very intermittent. Yesterday it almost stranded me at a thrift store but today it's starting just as well as it usually does (not well, that is). Should I replace the relay anyways and see if there is a difference?

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Are you sure you don't have a vacuum leak? There are several small hoses that connect the transmission modulator, charcoal canister, fuel pressure regulator, vacuum reservoir for the cruise control and HVAC and the big one easy to miss is the PCV system buried at the passengers side rear of the intake plenum.

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This is a good time to be looking at the built in diagnostics. Bad relay may make it slow to start but has nothing to do with running

 

For example are there any stored error codes ? What is the warmed up coolant temperature, closed loop status, instant and long term fuel mixtures, O2 transitions, & timing advance at about 30 mph cruise ? YWTK.

 

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On 5/1/2018 at 5:02 PM, BEMSTER 3 said:

Since then the strong exhaust scent has gone away but the mileage does not seem to have improved appreciably and it is starting even worse than ever. 

I should probably clarify at this point that I based this assumption on the mileage not improving by how far the gas gauge had moved, not by an actual calculation. I now know that my Reatta is getting almost 22 in-town, having used a full tank. The starting issue seems to be unrelated completely. 

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On 5/13/2018 at 11:45 AM, BEMSTER 3 said:

I also tried once without any relay plugged into the fuel pump and saw no difference.

 

I believe that confirms my theory that the fuel pump isn't being powered by the fuel pump relay but is being powered through the oil pressure sender.

 

Even without the fuel pump relay installed the fuel pump will be powered by a circuit thorough the oil pressure sender once the engine turns enough to build oil pressure. Take a look at the circuit below. The part of the circuit highlighted in blue is the normal route the power takes to the fuel pump. I believe your fuel pump is being powered by the circuit highlighted in yellow. The engine has to crank over enough to build a small amount of oil pressure before that circuit is completed. That would explain your extended crank times for the engine to start.

 

You can test my theory on what is happening by unplugging the oil pressure sender. If the engine will not start you have proved the fuel pressure relay circuit is bad.

 

fuel_pump_circui-2t.jpg

oil_pressure_sensor_location.jpgOil pressure sender location.
 

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49 minutes ago, BEMSTER 3 said:

I now know that my Reatta is getting almost 22 in-town, having used a full tank.

 

That is about what I get in my Reatta around town.

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Alright, so here's what I did...

 

Unplugged oil pressure sender only - still starts

Unplugged oil pressure sender AND fuel pump relay - does not start

Unplugged fuel pump relay only - still starts

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