Fuel Pump Relocation

[Tiramisu]

I have a 74 2.0 and would like to move the fuel pump to the front trunk to rid myself of the vapor lock prob. I dont see a kit here at Pelican so I was wondering if anybody had experience with the $15 kit AA has or the $110 kit Automotion sells. Thats a pretty big difference in price.

[campbellcj]

The difference might be that Perf/Automotion actually has the parts!

[bowlsby]

At one time I bought the AutoMotion kit for my '74 2.0...and immediately took it back before getting in my car.

It really is not hard to figure out, and not worth whatever they are charging. Its merely a 2 conductor wire to relocate the electrical connector, and a few feet of new fuel hose/clamps. The existing tunnel fuel tubing is reused. Oh and they toss in a new fuel filter too. Big deal. 2 years ago it was about $60 dollars...looks like times change. I think I am going to start buying P-car parts as a true investment...they seem to appreciate in price about 10% a year, so the returns would be handsome in todays financial market.

Study the fuel circuit in Haynes and your car and do it yourself. Pelican should post the How-To on this one...its too easy.

[Tiramisu]

Im all about instructions. I am liable to mess up something badly. A Pelican tech article on making the mod would be great..and a kit containing all the stuff too.

[gruntie]

Is it necessary anyway? When u turn on the ignition the fuel pump runs for 3-4 secs - u can hear it. Turn the ignition on & off maybe 3 -4 times before cranking the engine & this will run the pump enough to clear the vapour lock. U can actually hear the pressure regulator start to work when the vapour clears. The engine will then start immediately. I was all for moving the pump on my 2.0 but once I figured this out I never bothered: it works on the hottest of days.

[scg]

Tiramisu: For instructions, how about looking at a Haynes manual -- they have a pretty good picture/diagram of the '75 setup If I recall correctly (I don't have the manual with me at the moment)

[TimW]

AA’s kit is actually $45.

Having just replaces my upper and lower fuel lines, in retrospect I REALLY wish PP would have had a kit like their competitors (hint hint!). Precut length hoses with cartoon diagrams would have made things so much simpler. Instead I just bought stock line from PP, and spent a lot of time cutting, measuring, and ordering more line. (Thank goodness for the DD hose diagram.)

I can only imagine a kit would have provided the simplicity I was looking for, and in your case detailed instructions.

Also, the Haynes diagram for the ’75 setup will show the later style pump, so you’ll need do figure out how to hook up the early style pump when it’s relocated up front.

Gruntie: I guess I was sleeping during vapor lock 101. What’s actually happening in the lines that doing what you described clears? Seems like a lot less work than doing the relocation if it really works (and it doesn’t happen all the time).

[And just for giggles…I once saw a 914 pump wrapped in aluminum foil to shield it from heat, and subsequent vapor lock. Behold, the power of AL.]


[This message has been edited by TimW (edited 04-24-2001).]

[Wayne 962]

Hmm, I haven't done this to my 914 yet. Can someone write up a tech article for us?

-Wayne

[bowlsby]

IF its not copyrighted...maybe I'll send you a copy of the automotion instructions?

Let me know.

[HMeeder]

I employ Gruntie's method.

I give it 3-5 seconds before turning the key the rest of the way. I can't explain it in technical terms but my feeling is that the pump builds up enough pressure to overcome the vapor in the lines if you give it the time. I have considered moving the pump (the process looks very simple) but since I discovered a measure of patience, it just hasn't been any priority.



------------------
Herb
'72 1.7 Tangerine 'Teen
'74 2.0 Red Rustmobile

[TimW]

It seems reasonable considering any vapor in the line would be “pushed” through, right out the return line back to the tank. Unless the vapor gets into the injector run, in which case it would just sputter a bit out the injector tip. But I always though vapor lock caused a condition where fuel would not pump? Where the gas heats up, turns to vapor, and never gives the pump assembly a chance to pump gas, just vapor.

If it’s so simple to rectify when it does happen why does everyone relocate? Maybe I’ll be able to answer that at the end of this summer?

Look Herb, now I have cool sunglasses too!

I just love those little icons…

[red-beard]

I think you'll find the problem with vapor lock of the fuel pump is on the input side, not on the outlet side. I think that most of the vapor lock issues could be fixed with a low pressure "sender" on the supply line from the fuel tank. Add a carb type fuel pump from just below the tank. Might be cheaper too!

[pbanders]

Herb, holding the key 3-5 seconds won't have the same effect as turning the key on and off 3 to 5 times. The ECU lets the fuel pump only run for about 2 seconds for each turn of the key. I'm pretty sure that this pre-pressure is the only pressure provided to the FI system until the engine starts. The ECU has a fuel shut-off circuit that doesn't turn the fuel pump on until the engine is rotating at more than about 90 rpm. I could be wrong, but I don't think the starter spins the engine that fast.

If you've got vaporized fuel in the lines, maybe the best approach is to actually crank for a moment or two, then turn the key back and crank again. That will allow the system to pump out the vapor and get gas to the injectors.

Brad Anders

[HMeeder]

Hmmmm

You know, I have heard mention in posts before that the fuel pump shuts down shortly after the ignition is turned on(before starter is engaged) but on both of my cars, the pump runs continuously. (I shut down at the Jack-in-the-Box so as not to peeve too many people with my exhaust noise, but I leave the ignition on so I can listen to the radio and I can hear the pump merrily buzzing away behind the passenger seat. It'll buzz for 10 minutes if the service is slow. I have never heard either one of them shut down. BTW all fuel lines are solid, no leaks and pressure in the system is 34 PSI at all times.

Would anyone know if that is indicating a problem with the ECU? Or are my cars freaks? Is there a pressure sender that is supposed to shut the pump down after pressure has been established?

Perhaps I have naver actually experienced 'Vapor Lock'. I have read that while it is common, it isn't universal.

Food for thought, but the car runs fine.



------------------
Herb
'72 1.7 Tangerine 'Teen
'74 2.0 Red Rustmobile

[pbanders]

Herb, the ECU prevents the fuel pump from running after 1.5 seconds to prevent fire danger in the case of an accident. Check the ECU diagrams here at Pelican Parts to see the circuit block. If your cars don't do this, it's not normal, and is likely due to either a PO rewiring the system, or a fault in the ECU.

...but, no wonder you never have vapor lock!

Brad Anders

[TimW]

Ditto. My ’74 2.0L motor shuts the pump down after 2 secs.

Here’s an interesting bit, on 1.8L’s if the pump runs continuously it could be a warped air flow meter flap or a bent air flow points-set arm. You have a 1.7L & 2.0L, but this speaks to the fact that at least on the 1.8L’s there are things that can go wrong that will cause the pump to incorrectly run continuously.

Might be something you’ll want to research.

I went to a Jack-in-the-Box once in Minneapolis. Order the greasiest burgers I every had through the thickest bullet proof glass I ever saw. Ah the memories…

Tim

[Dave at Pelican Parts]

The D-jet pump also runs while the yellow wire to the starter has +12V on it. So there are three circumstances where the D-jet pump runs. One, when you first turn the key from "off" to "on", it runs for about 1.5 seconds. Two, when the starter motor is cranking. Three, when the FI trigger points are opening and closing.

At one point, I shorted the trigger point wires together a couple of times in order to help troubleshoot some possible injector problems. It startled me to hear the battery run for that 1.5 sec. So I tried it again. "Bzzzzt." That's when the lightbulb went off above my head--I'd heard that the pump only ran if your motor was running, but I didn't think about how the ECU would know that.

--DD

[HMeeder]

OK, so now I have to figure where to look to get things back to original.

One other bonus is the when I wanted to empty the fuel tank I just ran the fuel line to a canister and turned on the ignition. No Muss, no fuss.

------------------
Herb
'72 1.7 Tangerine 'Teen
'74 2.0 Red Rustmobile

[B Komar]

I just put a 73 2.0L FI motor in my 75 2.0L that had a holley progressive. My fuel pump was already in the front. I still have 2 plastic lines to the engine compartment..one was plugged up when it had the carb. There is only one line running from the Hazet fuel pump to the engine compartment. I am confused as to how to hook up these lines. Is the hazet going to have enough pressure to provide the fuel to the fuel injection? I still have the orig 73 fuel pump...should I use it instead? Brian

[bowlsby]

I think it s Facet not Hazet pump that you have for the carb setup... The Facet pump only puts out a few psi...the FI will require ~28.4psi, so you'll need the original 73 pump, and both lines (one is a return line). Haynes and other sources have good diagrams on how to hook them all up.