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Discussion Starter · #1 ·
my son took the 87 Suburban to work, and it quit running on the way home. acts like the fuel pump quit. well I looked and it's getting no fuel. it's a 350 TBI with the pump in the tank. so I guess on this, theres no fuel pump reset button. so wheres the fuel pump relay on a 87 Suburban ? I need to find the fuel pump relay I can jump it across. so I know if the fuel pump is getting power or not. If I jump the relay across, I can be sure if the pump is getting power. of course I just put $60 worth of gas in the tank. someone have a drawing / schematic on this fuel pump circuit ? or does someone have some advice to help me with this.


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I am not sure on a '87. I know on the later(newer body style)models the wire going to the pump that supplies power is gray in color. You can also jumper two terminals in the diagnostics test port that will bypass the relay to send current to the pump but I cannot remember which ones,sorry.

Fuel pump failures are pretty common on these vehicles. If it is the original or has been in there a while...I suspect it is bad. Try giving the tank a whack with a 2x4 or rubber mallet and see will it start,sometimes this works for a crank or two if its the pump.
 

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Discussion Starter · #5 ·
thanks 73 Oldsman, I will look that over. wish I could know more about jumping the two terminals in the diagnostics test port. anyone else have any ideas ?










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If you put battery voltage to the fuel pump prime connector you'll be jumping the pump. That red prime wire usually has a green end on it. The wire just sticks out of the wiring harness. Sometimes it's near the master cylinder area, but it's usually sticking out of a large bundle of wires. Be sure to use a fused jumper wire. After you jumper the fuel pump prime wire if the pump doesn't start, you can usually hear them, tap the bottom of the gas tank with a short piece of 2X4 or a rubber headed hammer. In fact you can try that while someone cranks the engine over to see if the engine will start. If it does then you'll be 98% sure you're dealing with a bad pump. The other 2% of the time it's bad wiring on top of the gas tank going to the pump. If the pump does start when you hot wire it test for a bad relay, signal to the relay from the ignition or possibly a wiring problem. Personally the first thing I'd do is hit the bottom of the tank while someone cranks the engine over.
 

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Discussion Starter · #7 ·
thanks ernkazern, where is the fuel pump relay located. it just quit running going about 20mph.

we checked theres spark but no fuel.

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Did you try having your son hit the bottom of the tank in the center while you crank the engine over? Believe it or not most vehicles with bad pumps will start if you do that. That trick only works a couple of times though. I don't know where the relay is off the top of my head and I don't have any manuals here. Usually it will be with a few other relays under the hood. Usually they're either on the firewall or behind the right headlight. You can match the wire colors with the colors in the diagram someone sent to determine exactly which relay is for the fuel pump.
 

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Mustangsaly said:
thanks ernkazern, where is the fuel pump relay located. it just quit running going about 20mph.

we checked theres spark but no fuel.

thanks
Well ... this is interesting.
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According to Autozone's "component locator"
The fuel pump relay (Their Part Number 19957)

On your 1987 Chevrolet Truck R10 1/2 ton P/U 2WD (5.7L TBI), the Relay is located:

Under hood, passenger side, upper firewall, mounted on relay bracket
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Autozone doesn't have a part image ... so I went to NAPA's website.
NAPA doesn't list a fuel pump relay for that vehicle, but they DO list a fuel pump relay connector ...

The AutoZone part number for the relay crosses to a NAPA (Echlin) P/N AR229SB ... and this is what it looks like:


This is NAPA's fuel pump relay connector (EC191) ... but it sure doesn't look like it matches the relay ... so I'm confused :confused:
 

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Another thing........this circuit runs through an oil pressure switch also..............so, if there is no oil pressure, the fuel pump wont run.
 

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That looks like a later model wiring harness end. The relay you show looks like a typical GM relay for your 87 model. Did you find the old fuel pump relay? There's usually numbers on it unless it's a cheap Chinese one. Btw, that sounds right for the relay location. I could be wrong about the relay style though. What do the relays look like that are on it? They should all be the square style or the rounded style.
That's a good point Poncho brought up, check the oil level.
 

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Discussion Starter · #12 ·
66GMC, thanks if I could get that Big Pig in the garage by my self, I would be out there locating the fuel pump relay (witch I think you made finding it pretty easy) its like 45 degrees out with a cool breeze.






Thanks Everyone
 

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Mustangsaly said:
...
its like 45 degrees out with a cool breeze.
...
Heck ... it must be nice to be living in the "banana belt" ... it's about 30°F here tonight, and 50°F was our high.
And today was a "nice" day ... ;)
 

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Discussion Starter · #14 ·
it's a GM Crate Engine 350 TBI that prob has 3000 to 5000 miles on it. it's always carried 60 to 65 psi cold and 45 + warm. maybe a wire is off the oil sending unit. I will check it out. and see if it's in the oil pressure switch or the relay or the fuel pump.


Long Story
the crate engine was in a p/u of a boy 3yrs older than my son. daddy bought the boy a nice 90 chevy p/u then the 700R4 tranny went out. daddy replaced it and the torq converter and then a piston broke a skirt, so daddy bought a GM crate engine and a local guy put it in. crate engine was in the p/u 3 months when it lost the drive shaft breaking the tranny around the bellhousing. daddy said sell it, and daddy bought the kid a late model chevy p/u. I got the complete engine (plus EFI & accessorys & radiator ect.) if I pulled it I could have it for $800. we put it in the suburban and we have drove the Suburban about $200 dollars worth of gas through it since new engine. it could be fuel pump or some wiring. I thought the bugs were worked out of it.
 

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Discussion Starter · #15 ·
my wife said this morning one day last week the oil pressure gage peaked at max on the gauge, 65 or 70psi I think. this was when she was parking, so she revved it up then waited for it to idel down and then shut it off. the gauge stayed at max psi till she turned the key back on a few mins later. I put a new oil sending unit on when I put the motor in early this spring. the sending unit is down by the oil filter. maybe that wire touched the exhaust ? it has a external oil cooler and the one piece bolts to where the oil filter goes.


thanks guys
 
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