Ironmahn

Would a 86 Trans Am that came with a 5.0 carb engine have a tank fuel pump or engine based pump?

Angelis83LT

it is pretty easy to tell.. look at your engine. If it has a fuel pump on the passenger side bottom of the block ( you will see your fuel line go to it) then you have the engine mounted one.. if you see nothing there.. and the line goes from your carb straight back to the tank without connecting to anything that can pump fuel. you have an intank. Parts houses are not the easiest place to get that info if you were to ever ask.. they think all third gen camaros came with in tank fuel pumps.

Ironmahn

I should have stated that the vehicle does not have the factory installed engine in it.

MaxxMitchell

iTrader: (4)

Still check to see if it has a block mounted pump. It could still have a intake pump depending on the PO that did the swap was lazy, making the mech pump pull through the old one. You could get under the car, and look by the fuel lines, see if there is a electricle connecter that has more than 1 or 2 wires (a intake pump will have 3-4 wires there). If so you might still have the intake pump still back there.

If it comes down to it, the gas tank is not that hard to drop out, you just need a friend to help at times. I had trouble with the filler neck when I went to drop, and reinstall mine, but I managed. Disconect the fuel lines, and electricel conecter. You do have to drop the rear, so both shocks, the panhard rod brace, and the passenger side of the panhard rod. The hardest part was getting the bolts lose on the panhard rod and brace, they were original, and haden't moved sense installed at the factory. I picked up new bolts for $1.58 at the dealer for two. I run a block mounted pump now.

1987earthquake

iTrader: (5)

Is there any way of telling without dropping the tank. I bought mine without an engine. Originally equipped with lg4 but going back with tpi.

Ironmahn

I will have to get back with you on that, it won't be till this weekend before I get a chance to look at the vehicle. Knowing my luck with this girl, I will be dropping the tank and fabin' some type of a pickup, lol. Oh yeah, I liked your burnout.

Bowtye101

It should have been a block mounted pump unless it was a fuel injected engine originally check your vin 8th digit call your local parts store make sure to tell them what the engine code is (8th) and you can find out what type of pump it came with.

Ironmahn

I will call, this is what I found so far... 8th in VIN is H 305-155 (LG4). The RPO sheet in the vehicle does have the same VIN number as the body, and the LG4 in that list. Looks good so far.

MaxxMitchell

iTrader: (4)

Read my post above yours. Check for wires going to the tank is one possibility.

1987earthquake

iTrader: (5)

I read on this site somewhere that the lg4 came with both the electric in tank pump and the mechanical pump? Is this true?

Angelis83LT

yea. there are a few carbed ones that do have an intake.. i have seen them sitting in the junkyards... easierst way to see if the tank has the intank pump is to check for wires going to the tank... thats pretty easy to do. just go, jack the rear up.. slide under it till you can see the front of the tank.. and you should be able to see if there are any wires. if there are wires. you have an intank.. no wires, no intank.

Codename 47

iTrader: (4)

Properly block the car before sliding under it too.

JamesC

iTrader: (5)

My LG4 didn't have an in-tank pump. IIRC, the only carbed car to have the in-tank was the L69.

JamesC

Ironmahn

Well, I got under her last night and there are two wires (black and red) that go to the tank. I assume that this would be just the float assembly/sending unit and not in the tank style pump... thank goodness. There is also four hard lines one of which is a vent. I take it that an in the tank would have a third wire that would power the pump?

five7kid

iTrader: (14)

Sounds like you don't have an in-tank pump. From what I've been able to gather over the years, there are 3 ways you could have an in-tank pump with a 3rd gen carb'd engine:
1 - L69 (and it isn't clear to me that they all had the in-tank pump)
2 - '87 model year. Apparently that last year of the factory carb they put the in-tank pump in all LG4 models (L69 no longer available). Since everything else was EFI with an in-tank pump, I guess they figured it was simple enough to put it in the LG4 as well.
3 - dealer installed. If an owner complained about vapor lock, one of the solutions was to install an in-tank pump. You could also get a blower installed that blew air from the fenderwell onto the carb when the engine was shut off - my donor car had that feature, but as far as I could tell, no in-tank pump (at least it didn't have the relays for it, I never dropped the tank before I had it hauled away).

1987earthquake

iTrader: (5)

I have an 87 came factory with lg4. So does this mean mine has an in tank pump. or at least the wiring for it. I'm in the process of converting it to tpi. I bought it without the engine. I figured $200 for a 87 camaro still has the 700r4 in it too. It just got put in or rebuilt last July. I found a reciept in the car. The paint didn't even look bad, even with a fender bender on the front driver side. But oh well I still think I got a great deal.

jstoltz

iTrader: (16)

it will have an in tank if it unless some one yanked it but if stock it's there

dcd2236

iTrader: (4)

ok thats wierd so 87 LG4s had a in tank pump, so that means my 87 lg4 has one in tank along with a block mounted pump??? was that possible to work with???

dcd2236

iTrader: (4)

So if the LG4 came with an in-tank pump also, what kinda PSI would those pumps put out??

five7kid

iTrader: (14)

Not a lot of pressure. Similar to the TBI pump.

I'm not completely clear how the factory regulated pressure, may have been the same return on the engine-mounted pump; regardless, the carb is only going to see 6 psi.

The purpose of the in-tank pump wasn't to supply pressure, but to push the fuel to the engine mounted mechanical pump. With the fuel in the line going to the mechanical pump under pressure, it won't vaporize and vapor lock.

It's actually a good way to go if you can.

dcd2236

iTrader: (4)

do you have photos of what the sending unit and pump look like from an LG4 car. Could someone take that pump and change it out with a pump for a TPI and not have to change the entire sending unit, tank and all, just maybe the rubber fuel lines and the metal lines to make them run to the drivers side for hooking up to the tpi fuel rail.?

duckmanquacker

this might help. if your car in 87 had either the LG4 or L69 you could have had the mechanical engine mounted OR the electric intank pump. the intank pump was the same specs as the TBI pump. if your car was carbed it likely has the mech pump. if it was built late in 87 it could have the electric pump from the transition of carb to TBI.

five7kid

iTrader: (14)

I don't have the electric on my car, but from what I've understood, if you have a carb'd engine, you will have a mechanical pump. '87 had an in-tank electric pump in addition to the mechanical, and the in-tank electric could be added by a dealer as part of a vapor lock kit.

Never "or", maybe "and".