davidc212k

iTrader: (3)

You are correct. i just didnt have the diagram in front of me.

Here is how its setup currently.
#86 - to PCM for the FP Relay Control(wired as part of the harness). green/white wire.
#87 - to fuel pump. Not sure were it should go on the fuel pump.
#85 - Ground which is part of the harness to ground. black wire.
#30 - 12V power

On the factory FP Relay.
i noticed i have:
#86
#87
#87a
#85
#30.

What i basically tried to do was connect the #30 and #87 from the harness FP relay(not factory). the harness has its own seperate FP relay.

i connected those to wires to the factory FP Relay. to the respective #'s
Got no Fuel Pressure or prime.
I didnt check for voltage on the #30 with a multimeter.
But since i havent connected the oil pressure sensor, which i believe triggers for the fuel pump to get voltage. i may not getting power to #30.

Here in a few minutes i will connect the oil pressure sensor/wire to the appropriate gauge connector, but before i do that i will check for 12v on the #30.

wish me luck broskies.

the_merv

iTrader: (88)

Oil Pressure has nothing to do with the Fuel Pump...

This is the correct way for that Relay:

#30 - 12v Fused source power in.
#85 - Relay Ground.
#86 - PCM FP Relay Control (12v Exciter).
#87 - 12v supply to the Fuel Pump (POWER)

Don't worry about 87a.


You'd think when you spend $500 for something from a company they would have good enough customer service to where you don't have to come on a forum searching for answers on the pile of **** you bought from them.

mantycarguy

The factory diagram shows terminal 85 as the 12 volt feed from the pcm to the relay and terminal 86 as ground. It appears as there is a diode or resistor in the relay to prevent a backfeed / voltage spike from occurring as the fuel pump turns off. To check for the pcm feed signal place one voltmeter lead on terminal 85 and the other lead to ground.Turn the key on/engine off and have a buddy monitor the voltmeter as you do this You should see battery voltage for 2 seconds indicating fuel pump prime. As you begin to crank the starter the pcm then sees an rpm signal from the crank sensor which signals the pcm to enable a steady 12volts to the relay pin 85. Pin 87a will also have b+ voltage when no prime or no crank signal from pcm is received.Themerv is correct as the oil pressure switch has nothing to do with fuel pump operation on the ls motors. On earlier TPI and LT1s the oil switch served as a backup in the event of a relay failure.

davidc212k

iTrader: (3)

Gotcha, I will give this a try. Thanks for the huge help.

davidc212k

iTrader: (3)

Ok lets see if i got this correct.

#30 - 12v Fused source power in. - I have to provide 12v from a source(alternator) to this wire with 15 amp Fuse
#85 - Relay Ground. - Goes to Ground
#86 - PCM FP Relay Control (12v Exciter). - This exits and goes to the PCM.
#87 - 12v supply to the Fuel Pump (POWER) - This has 12v and goes to the Fuel Pump.

mantycarguy

Reverse 85 and 86. 85 comes from pcm and 86 is to ground. This is the way the factory wired them. OK on the 30 and 87 terminals.

davidc212k

iTrader: (3)

Gotcha. I will give this a try this afternoon. If this works out.
I owe you one pal.

fire67bird

It's not really fair to bad mouth the harness vendor. There is a learning curve for these type of projects and mistakes are made all over the place by all involved. The customer can order the wrong part, misread the instructions, or other factors cause problems, and no I don't work for PSI but those who depend on employment there depend on the company sales for their livelihood. Onlinereviews DO impact sales and I think we should be fair in our criticism.

the_merv

iTrader: (88)

The biggest thing to me is the fact this guy has to come here looking for answers on something that should be answered by the company. I have dealt with many companies and they ones that have the best customer service have always gotten my business and referral. You cant even put the time into customer service then you don't care about your customer or product.

This case here if he's not getting help they took his money and left him hanging, that **** isn't cool.

davidc212k

iTrader: (3)

The fact of not having the #30 to a 12v source. Does that affect not getting battery voltage for 2 seconds from #85?

the_merv

iTrader: (88)

No. 30 is the in, 87 is the out, 85 & 86 is the switch basically.

crawlingt

I didnt read every post but I seen you didn't disable vats. I have seen this cause a lot of problems as far as no starts, most people have success after disabling it.

davidc212k

iTrader: (3)

I tested 85 and 86 and got nothing while on ground. I guess I'm not getting a pcm signal feed.

mantycarguy

Is your pcm grounded? If so, the vats system must be deleted from the pcm to enable fuel pump signal.

davidc212k

iTrader: (3)

yea pcm is grounded. the harness itself has a built in ground wire to the passenger side to ground. il do the VATS bypass and see if i get something. thanks again.

davidc212k

iTrader: (3)

i did a voltage test.
I got 11.85v for the #87 and got 0.02v for the #86.
as for #85 thats for ground and #30 i got 0v.

That is for the factory FP relay wiring.

davidc212k

iTrader: (3)

Also on #87 the wire on the relay is orange.(12v out to pump)
but on fuel pump side that 12v wire is grey.
There is a grey wire on the relay that is a different #.
Anyways tomorrow i get my tuned PCM with VATs and several things disabled.

davidc212k

iTrader: (3)

i got the PCM tuned with vats disabled and the fuel pump still is not priming.
I also got error code P1336.

BP Automotive

iTrader: (3)

Have you cut into any of the dash harness in your car? Do you still have the original engine harness?

Bill

davidc212k

iTrader: (3)

I have the original LT1 harness.
I installed an ls1 harness with the required wires to the dash harness
The only wire that i have a doubt is the wire for key on crank. i have it connected to the LT1 C100 Cavity G Pink wire for power feed from ignition fuse 11.

Im getting no fuel pressure of course. i have vats disabled. no prime whatsoever on the fuel pump. i was told if the crank sensor isnt working. it can cause no signal to be sent to the PCM for the fuel pump to prime.