87 3.8 low fuel pressure

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87 3.8 low fuel pressure

December 24, 2009, 05:05:36 PM

My 87 3.8 decided to quit running recently. I was low on fuel, so I added a few gallons thinking I was out of gas. It wouldn't start after that. I have spark, and the car will run on starting fluid.

It seems to have low fuel pressure. I've disconnected the fuel line prior to the filter and had my s.i.l. turn the key to run the pump (not a great idea, but it worked). Fuel did run from the line, however virtually no pressure behind it. Pressing the core of the pressure release valve in the injector body gives virtually nothing.

I've searched for similar postings and have seen issues with in-tank rubber lines rotting away, however I didn't see a posting about an 87. Any suggestions?

Thanks

87 3.8 low fuel pressure

Reply #1 – December 24, 2009, 06:26:05 PM

do you hear your fuel pump turn on when you turn the key on? it could be your fuel pump?

87 3.8 low fuel pressure

Reply #2 – December 24, 2009, 06:34:31 PM

I can hear the pump run when the key is turned to the on position. We checked for fuel flow before and after the filter by removing the fuel lines from each side of the filter to rule out a clogged in-line filter.

87 3.8 low fuel pressure

Reply #3 – December 24, 2009, 07:02:06 PM

how low did you run it on gas exactly?
low enough to clog up the fuel pump strainer possibly,
or enough to make a weak fuel pump out?

87 3.8 low fuel pressure

Reply #4 – December 24, 2009, 09:22:59 PM

on the drivers site strut tower there is an eec self test connector where you pull codes from.

look for tan/light green wire.
ground tan light green wire to chassis
turn on key, no start.
fuel pump will run constantly

lay contaner near shrader valve (fuel pres test port)
sharder valve is what you pressed in before on the upper part of the CFI.

Fuel should spray out like hell all over the place up there.

if it just dumps out kinda lazy like, your problem is in the tank as you have also verified the fuel prior to the filter is low pressure.

Jumpering out the wire i mentioned here keeps the pump running. if you just turn on the key, the pump runs for about 2 sec then cuts off which makes it a pain to troubleshoot.

Yes you are correct about a 2'' long rubber line dry rotting in the fuel pump assembly. If you are interested in dropping the tank, replace your pump with 1990 3.8L supercharge pump as it runs about 90L per hour vs your 60 Liters per hour bosch pump.

you really need to borrow a fuel pres tester or buy one at advance with the adaptors to fit most cars.

you can also make your own fuel pres tester with a section of hose and the same thread pattern nipple to install in place of your shrader valve. A nipple clamped to a hose and a 100psi water guage clamped on the other end does well for what is required and you can usually find this stuff lying around most peoples house.,,except for the nipple.

87 3.8 low fuel pressure

Reply #5 – December 26, 2009, 09:52:03 PM

Ductape91 - It was running fine up until this (had the car for about 2 years, put 13k miles on it in that time). While driving it began to buck/surge like it was low on fuel. The gauge was showing just below 1/4 tank at the time. Pumping the throttle kept it running long enough to get it to a gas station. After that, it cranked but wouldn't fire. It would light up on starting fluid.

jcassity - sounds like it's time to drop the tank. Thanks for the '90 fuel pump suggestion. Can you tell me if the fuel lines are flexible enough to do this in a semi-heated (40-ish degrees) garage without damaging the lines? The fact that I'm working with 22+ year old lines definitely won't help.

Also - has anybody ever created an access panel in the trunk floor to allow pump removal from above the car? Is it even feasible?