graebz28

iTrader: (5)

Going off of my last thread. old thread

I got TDS AFPR and new spring. I installed it on my TBI with BBC injectors, jumped the FP relay and never got above 13 psi. I pinched the line and it almost got to 15. It is a fairly new pump that I got off ebay that is supposed to be a walbro 190 spin off.

The FP gauge tap is on the supply line. I thought that I recalled seeing that it may have to go on the return line, but that does not make sense to be since it would be downstream of the FPR.

The spring from TDS was considerably longer in length. The only one that they sell now is for VAFPRs. Is that the one I should be using?

Is my pump dogged out if my max is 15. I might try changing the fuel filter.

thomas1976

Im using that one with a stock FPR modified to be adjustable and its holding 21psi without hesitation.

15psi with pinched line is to low for walbro190, should be 40psi+?

graebz28

iTrader: (5)

Thanks Thomas. I guess all I can hope for now is a clogged fuel filter or the tank is coming down .......... again

I do not want to chance during initial engine break-in to not have enough fuel. I guess the FP gauge could be off, but it has only been used a few times.

thomas1976

Yes dropping the tank is not fun.

Also make sure there is no air in the gauge hose for precise reading.

graebz28

iTrader: (5)

Yeah, I ran fuel out of the gauge purge into a gas can for a bit hoping it would get better.

Is it possible to have air still inside the line or regulator? Do you ever have to crack the return line or some other way bleed the line?

graebz28

iTrader: (5)

Well, fuel filter changed and I still do not get crap for pressure. I even check my gauge vs. air compressor line pressure and even screwed in my old tpi gauge. I checked the resistance at the connector near the tank and it was less than 150Ohms.

I did a flow test and got 12 oz per 11 seconds. If my math is right, I am getting 30.68 gph or 116 lph free flow. Around 60% capacity if it is truly a 190lph.

All I can think of is that the pump or the line from the pump to the sending unit.

titchener

Before you drop the tank, put a voltmeter on the pump wiring right before it goes into the tank, you should see close to 12 volts there when the pump is on, if you see less than 11 or so check the wiring carefully for corroded connections and if it looks ok try a new pump relay.

Paul T.

graebz28

iTrader: (5)

Too late. I think I got the tank down in just under two hours but I did have a head start since the d/s and t/a were already removed. The wires at the connector look good. I measured 12.8 at the batt and at the orange relay wire. When I fired up EBL, it said the same. I was jumping the orange to gray when doing the test, but I will jump it again and get the voltage at the connectors. Thanks for the post, Paul!

My good friend TonyC sent me his extra walbro 190 since he got an LS1 tank that he is going to use.

Anyone got a good way to test the pump out of the tank? I could hook the sending unit right to the rubber line near the engine and run the return somewhere. Reason being is that I have three older pumps that I would like to test and sell or throw away.

titchener

For the test to be valid you need to measure the voltage right at the pump with the pump running under load. With no load on the pump, or the with the pump disconnected you'll always measure the full battery voltage, what you are looking for is too much drop under load, which means extra resistance somewhere in the circuit, usually corrosion.

One other common problem is the wiring harness that connects right to the pump in the tank, these can get fried over time, take a close look at yours if you didn't replace it when you put the pump in.

Another common problem is a split in the all of the hoses that connect directly to the pump, take a close look at those.

Paul T.

graebz28

iTrader: (5)

That was the reason I replaced the pump last time. Be careful what you ask for. I prayed that it was not the pump being the problem and it wasn't. It was the hose mentioned above.

I placed worm clamps on it last time. I pressurized it somewhat with my air nozzle and it did not appear to be split.

I replaced the wires in the tank as well.

I just hope that when I put in the Walbro that I get the pressure expect. If not, I do not know what the problem could be. Maybe the regulator? Can't see that being the problem since the pressure was crap with the return pinched.

All I know is that I am breaking in the motor w/o reassembling the rear end and such.

I could submerge the pump in a suitable container outside of the tank and measure the voltage there under full load. Thanks for the suggestion.