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Checking lift pump

You can find a 5 terminal 12V relay most parts stores.

Here is one with the internal coil supression, which seems difficult to find
http://www.wiringproducts.com/contents/en-us/p564.html

You can also find relay harnesses/sockets that have like 12" leads coming out of a socket, or even a dual socket for two. Or just use female blade crimp terminals, which if thats what i do I like "weather proof" crimp termainls just because they have the whole terminal covered so less chance of corrosion or shorting. For proper crimping I use a heavy duty tool like this that has two sizes (not all have two sizes)
http://www.google.com/products/cata..._result&ct=result&resnum=4&ved=0CHYQ8wIwAzge#
And not those skinny mickey mouse crimpers that just smash the terminals down, not really any better than using a pliers. For crimping it has to wrap the terminal around itself sort of, indenting one side essentially. And you indent the side that has the terminal, because the other side of the crimp is not solid (it is butted together).
 
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When I was trying to run fuel pump I ran the ground right off the battery. I grounded to the connector and I tried grounding to the case of the LP with no results. I'm going to get my tester and check the battery ,I did check it with my volt meter and it checked ok.

Mark
 
The connectors that are made to install in the relay plugs are the oem style. I was wondering if they make a different style crimper for those. They have the little catch on back to keep them in the relay socket.

I'll have to try the prewired relay sockets.

Do you have a link to those?

Thanks

You can find a 5 terminal 12V relay most parts stores.

Here is one with the internal coil supression, which seems difficult to find
http://www.wiringproducts.com/contents/en-us/p564.html

You can also find relay harnesses/sockets that have like 12" leads coming out of a socket, or even a dual socket for two. Or just use female blade crimp terminals, which if thats what i do I like "weather proof" crimp termainls just because they have the whole terminal covered so less chance of corrosion or shorting. For proper crimping I use a heavy duty tool like this that has two sizes (not all have two sizes)
http://www.google.com/products/cata..._result&ct=result&resnum=4&ved=0CHYQ8wIwAzge#
And not those skinny mickey mouse crimpers that just smash the terminals down, not really any better than using a pliers. For crimping it has to wrap the terminal around itself sort of, indenting one side essentially. And you indent the side that has the terminal, because the other side of the crimp is not solid (it is butted together).
 
For crimping pins or sockets that go into a connecter I do just use a needle nose pliers, and not simple. I press the tabs together over wire, then I flatten them over the wire and then pinch together, but then I solder the tip of the wire on it so it cant pull out.

Here are some prewired that you can just use butt crimps or solder your wires to.
single
http://www.allelectronics.com/make-a-store/item/SRLY-2/SOCKET-FOR-AUTOMOTIVE-RELAY//1.html

dual
http://www.allelectronics.com/make-a-store/item/SRLY-4/DUAL-SOCKET-FOR-AUTO-RELAY//1.html

Or other places sell them, I have used partsexpress.com for stuff before.
 
Have another question, what would be the better of these two LP's a Delco for a 93 GM or an Airtex E3540 the later being about $20 cheaper? Thanks.

Mark
 
I had the same problem [leak in valley] and the line was pinched, I only had 1/2 lbs. pressure until I replaced the line. Now at 5/7.

You have to fix all leaks before diagnosing the LP. Start w/line from FFM to IP and then prime to see if resolved.

I did the same tests you have and fill bottle w/fuel and had cut off issues.

It doesn't tell the truth because there is no resistance until you put a gauge on it to load the pump.

That's why pressure drops as load and rpms increase, your're using more fuel and therefore L/P has to keep up w/demand.

Only after testing F/Pressure before and after line replacement did I know true pressure going to IP.

As far as not working with 12v direct to L/P you have the probe on the wrong pin or maybe ?
 
Also check out PMDcable.com for the OPS extenstion. It is a 1/4" steel braided hydraulic line with crimped on ends that ground the OPS to the engine block. It makes accessing it much easier. I got an OPS socket on the wall at my local Napa, thats what its called.
 
I had the same problem [leak in valley] and the line was pinched, I only had 1/2 lbs. pressure until I replaced the line. Now at 5/7.

You have to fix all leaks before diagnosing the LP. Start w/line from FFM to IP and then prime to see if resolved.

I did the same tests you have and fill bottle w/fuel and had cut off issues.

It doesn't tell the truth because there is no resistance until you put a gauge on it to load the pump.

That's why pressure drops as load and rpms increase, your're using more fuel and therefore L/P has to keep up w/demand.

Only after testing F/Pressure before and after line replacement did I know true pressure going to IP.

As far as not working with 12v direct to L/P you have the probe on the wrong pin or maybe ?


Thank's for the input Rob. No I'm pretty sure I had it hooked up right. I checked the battery I was using to test the LP and it checked out 100% charge. I'm getting ready to go out and mess with it a little more while I'm waiting for parts.

Mark
 
Also check out PMDcable.com for the OPS extenstion. It is a 1/4" steel braided hydraulic line with crimped on ends that ground the OPS to the engine block. It makes accessing it much easier. I got an OPS socket on the wall at my local Napa, thats what its called.


Yeah I saw that before I'm glad you reminded me of it now would be a good time to do it.

Mark
 
My lift pump isn't dead, what happened was the jumper I was using had a bad ground wire on it, both pair of my jumper's had bad ground wire's. The jumper's were new I bought them at a swap meet this past summer made in the USA, they just didn't tell you that they were defective.

Mark
 
That's nice.

If your OPC isn't bad. I wouldn't mess with changing it. With the relay upgrade it may last forever.

Actually on the 95 Tahoe, I haven't gotten around to changing the bad OPC yet. It puts out enough voltage to activate the relay - so it works - but it wouldn't run the Lift pump on it's own. It's on my to do list but not high priority as long as the LP is working.

My lift pump isn't dead, what happened was the jumper I was using had a bad ground wire on it, both pair of my jumper's had bad ground wire's. The jumper's were new I bought them at a swap meet this past summer made in the USA, they just didn't tell you that they were defective.

Mark
 
I ordered a OPS extension hose from PMD so it won't be a problem changing if it goes bad.

I'm going to go to the local Mack truck dealership and see if I can come up with the fitting's to do the FTB mod.

Mark
 
Hey Buddy has anyone found a source for the steel 6 an fitting for the top of the IP yet?

And what is the socket size for the OPS? Thanks.

Mark
 
Yes, Walking J sells a "full flow" 7/16"-20 O-ring to male -6AN steel fitting. I call it full flow because its ID is the same size and 3/8" line. I am using one, its great, no need to bore it and no worries about snapping the small bottom part off. You can still buy just that from them.

http://walkingjdesigns.myshopify.com/products/feed-the-beast-ip-fitting

Otherwise their FTB2.0 is more my kind of setup.

I used all Russel "full flow" fittings on mine, like these
http://www.summitracing.com/parts/RUS-613450/
http://www.summitracing.com/parts/RUS-610020/

but here is a steel 150* elbow http://www.summitracing.com/parts/EAR-415006ERL/

I do have a couple elbows and the steel one is definately better quality, much heavier quality, but costs more and not sure the ID is as big.
 
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