Mitch8895

Hello everyone,

I have a stock 1988 convertible that is giving me some trouble. Let me first say that the car sat for approximately 8-9 months since I have driven it (I had to move away for classes) with a known issue. The car would fire up, run for a few seconds, and then die out. I am just now getting to diagnosing the problem. Thinking the problem was fuel related, I tested the fuel pressure at the schrader valve on the fuel rail. When switching the car to the on position but not cranking, I can hear the pump turn on and there is fuel at the test valve. The pressure gauge will read 8 PSI when the pump is priming and then drop to 0 PSI as soon as the pump stops running. After starting the engine, the pressure once again goes to 8 PSI and holds steady. The engine will start fairly easily and idle indefinitely with the MAF sensor unplugged (which I believe puts the car into "limp home mode" by maxing out the fuel system), but as soon as you give it any throttle, it will die instantly. I suspect that I have a bad fuel pump due to the lack of sufficient pressure, but I wonder about the instant loss of pressure. Could I also have a bad pressure regulator? I'm not sure where to go from here, I have a fuel filter on the way already but don't want to throw money at problems I may or may not have!

Thanks in advance, I'm kind of getting crazy over here!

antfarmer2

Pull the vacumme line off the fpr and smell for fuel. And could be a bad pulsater off the fuel pump. It can be replaced with a piece of proper hose that can be submerged. Could also be leaky injectors.

Mitch8895

I pulled the vacuum line off the pressure regulator and noticed a slight fuel smell, but no fuel seems to be inside the line. I suppose the fuel smell could indicate a leaky diaphragm inside the FPR? Also, is there any way to test for a bad pulsater without pulling the sending unit?

Thanks for the quick reply!

antfarmer2

You could pinch of the return line and see if the pressure go's up but still would not know. The pump is the easyest you will ever do. The fuel filter will make up for it. I would get a new sock too.

Pres712

Same thing happened to me but I was stuck in the Keys with no way to test anything. It would idle but when given the gas it died. Turned out to be the fuel pump.

Mitch8895

I just finished the fuel filter replacement.

A lot of crud came out of the old filter so I was hopeful at first, but now I read no pressure at the fuel rail. So I think it is safe to assume I have a bad fuel pump now. I did start the car with the mass airflow sensor plugged in and it ran for longer than it would before, so I'm sure the filter helped, but its looking like I am placing a fuel pump order sometime in the near future.

antfarmer2

Good job get a new sock too. did you turn the key on a few times to fill the system without starting?

aklim

http://www.lingenfelter.com/product/RXC44-FPA-A.html

No trips to the hardware store for anything besides your normal hand tools and bolts are all replaced.

Mitch8895

Fixed!

It turns out that the short rubber hose that connects the fuel pump to the sending unit had completely disentigrated and would not hold any pressure at all. Put the new pump in anyway and repaired the line, and she fired right up and responds to throttle now! Now on to fixing the idle (I moved the TPS when diagnosing the problem, so now I've got to reset the idle speed), give it an oil change, and get back on the road!

Thanks for the help, guys! It sure feels good to move on from this!

aklim

What short rubber hose? Why? If it is what I think it is, some moron had put simple hose there and not made sure it is fuel resistant.

You don't have to reset min idle if it is just TPS. OTOH, it is a good idea to take the TB out, remove the IAC, remove the housing, clean the crud out of it, reassemble with NEW GASKETS, check timing, use scanner to set minimum idle and then TPS. I'd do 20 counts for IAC with engine at stable operating temp and everything but motor off.

93Rubie

You NEED SAE 30R10 hose. It is designed for the in-tank environment. Also due to the pressure I recommend using actual fuel injection hose clamps NOT worn drive clamps.

You can do it right or do it half assed, your choice, your car.

aklim

Actually, you can do it right or do it again and again till you learn to do it right. Or at least, that is the lesson my Dad always tried to teach me when I did sloppy work.

http://www.racetronix.biz/itemdesc.a...IK-006&eq=&Tp=

I'd send email to them but I believe this is the kit required. Comes with new bolts and hose and gasket.

antfarmer2

That used to be your pulsater someone replaced it with the wrong type of hose. Make sure the one you put in is right and can be submerged in fuel. Or you will be doing it again and guaranteed it will not be where you want.

Good job