[Supras] Fuel pump system priming and pump resistor

[berniek at technicaldevelop.com]

Tom, Dan:

    Thanks for the information.  It is much appreciated.  I've already 
drilled out the J tube.  I installed a "cleaned up" JDM engine in my 
recently acquired '91T but should have put the entire engine together 
when on the stand.  Instead I installed it with the lower intake on the 
left side, but the full turbo and exhaust on the right side.  The vacuum 
hoses, EGR and solenoid valves are taking a lot of time now that the 
engine is in the car.  I extended the wiring harness and hoses to locate 
both solenoid valves on the top for easier access in the future, since 
there is enough to deal with below the intake manifold. 

    Dan:  I'll leave the resistor in place but doing electronics work, 
maybe I'll parallel it with another resistor to reduce the value.  I 
just hope I did not get stuck with a Chinese copy of the Walbro pump.  
It was bought in August of 1995, probably (hopefully) too early for the 
Chinese very close copies. 

       BernieK

Dan Gyoba wrote:
> On 5 Sep 2007 at 5:26, tom wrote:
>
>   
>> Bernie, I left the resistor in place.  No problems.  I did have to
>> replace the regulator soon after the swap.  I installed the one from
>> the NA and have been running it for two years.   Tom 87NA-T Lexus,
>> Lucas 550's, Walbro. 
>>     
>
> I've been paying a bit more attention to this lately, since I'll be installing a Walbro as soon as 
> I get the time to drop the tank, and before I start upping my boost levels.
>
> The information that I've gathered so far is that the regulator should be replaced.  The 
> restriction in the "J" tube should be drilled out to deal with the potentially higher flow.
>
> Many people like to bypass the FP resistor entirely, (Usually just jumpering the relay works for 
> this.)  I've seen many dyno graphs at elevated boost levels where the FP resistor does not kick in 
> soon enough, and the result is that the engine goes slightly lean, then suddenly kicks into pig 
> rich.  This problem seems to be exabberated when using piggyback fuel tuning, since it doesn't 
> catch right when the FP triggers.  I don't like lean conditions, nor do I really like the rich 
> spike, so I'll most likely take care of this at about the same time as I install the fuel pump.
>
> I would definitely leave the resistor in circuit until the restrictions in the fuel flow are 
> removed.  I am also budgeting for an aftermarket fuel pressure regulator for when I do all this.
>
> Dan Gyoba
> '89 NA 452,533 kms, Turbo swap COMPLETE
> http://www.abstractconsulting.com/~dan
>
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