Going to try two more things before I quit...electric fuel pump and questions

[twmattox]

I think I am ultimately going to go to an electric Holley Red Top...but want to fix the issue first. It is a bit long...but I have 3 big questions.

1) How do I plumb this in on the carburetor end? The hard stainless line screws into the mechanical pump. If I eliminate the mechanical pump...how is that steel line supported??

2) Is a Rotary Vane (Carter/Holley) better than a Solenoid (Carter/Airtex)? Everyone seems to like the Rotary Vane design...but the Solenoid design is not supposed to have any rubber diaphragm that gets deteriorated by ethanol.

3) Anyone have issues with fuel tank delamination? I have the stock plastic fuel tank...I know some brands of plastic tank have had issues with delamination due to ethanol.

Below is a brief history if you want/need to read...

The shop swears they have fixed the issue...they said it was just out of gas. They filled the tank (with 5-gallons) and said all was right in the world. Last time I knew...we had a 20-gallon tank. Seems odd that I could only use 1/4 of it. So, I am not overly confident the issue is repaired.

Last summer (about a year and a half ago) I replaced the fuel tank strainer / sock / whatever you want to call it. I noticed some large black flakes in the tank. Cleaned them out as best I could. Ran great for about a year. Then this last July I started getting issues with fuel delivery. Not sure if it was starvation, vapor lock, or what. I have replaced all rubber lines, new fuel pump (mechanical), new fuel filters, carb rebuild...the problem would seem to go away for a short time and then return.

I have verified that the fuel pump works within spec (both pressure @ 6.5", vacuum @ 12", and supply). And I have verified that the fuel filter works. The only thing I haven't checked is the fuel tank strainer / sock. It dawned on me a couple days ago that if this thing is plugged, it would increase the vacuum that the supply line is under. Increased vacuum means decreased boiling point for the fuel. So, if the fuel sock is partially or fully plugged, it could increase the vapor lock situation. So, today I plan on testing.

According to the FSM, I need to "T" a vacuum gauge just before the mechanical fuel pump. Then operate the engine at 1500rpm and monitor the vacuum reading. It should not exceed 3" vacuum over the course of 30-seconds. In addition, I plan on placing a clear fuel filter right before the "T" for the vacuum gauge. I want to see if there are any bubbles indicating a pinhole leak in the fuel lines.

I will post up my findings. Like I said above, ultimately, I want to fix the underlying problem. But, regardless, I think I am still going to switch over to an electric pump. If I am going to keep this, it needs to be 100% reliable. From everything I have read on numerous forums for numerous vehicles, the underlying recommendation is that a mechanical will work...but an electric is a bit better.

[grand_wag_85]

If you're going to ditch the mechanical pump altogether it's a good idea to reroute the steel hard line away from the heat.

As far as fuel pumps go my pump of choice is the E8012S Airtex pump. They're inexpensive, available everywhere and I've always had great luck with them.

You still want to use the return line and clock the small return nipple at 12:00.

[Rich88]

I think I am ultimately going to go to an electric Holley Red Top...but want to fix the issue first. It is a bit long...but I have 3 big questions.

1) How do I plumb this in on the carburetor end? The hard stainless line screws into the mechanical pump. If I eliminate the mechanical pump...how is that steel line supported??

2) Is a Rotary Vane (Carter/Holley) better than a Solenoid (Carter/Airtex)? Everyone seems to like the Rotary Vane design...but the Solenoid design is not supposed to have any rubber diaphragm that gets deteriorated by ethanol.

3) Anyone have issues with fuel tank delamination? I have the stock plastic fuel tank...I know some brands of plastic tank have had issues with delamination due to ethanol.

Below is a brief history if you want/need to read...

The shop swears they have fixed the issue...they said it was just out of gas. They filled the tank (with 5-gallons) and said all was right in the world. Last time I knew...we had a 20-gallon tank. Seems odd that I could only use 1/4 of it. So, I am not overly confident the issue is repaired.

Last summer (about a year and a half ago) I replaced the fuel tank strainer / sock / whatever you want to call it. I noticed some large black flakes in the tank. Cleaned them out as best I could. Ran great for about a year. Then this last July I started getting issues with fuel delivery. Not sure if it was starvation, vapor lock, or what. I have replaced all rubber lines, new fuel pump (mechanical), new fuel filters, carb rebuild...the problem would seem to go away for a short time and then return.

I have verified that the fuel pump works within spec (both pressure @ 6.5", vacuum @ 12", and supply). And I have verified that the fuel filter works. The only thing I haven't checked is the fuel tank strainer / sock. It dawned on me a couple days ago that if this thing is plugged, it would increase the vacuum that the supply line is under. Increased vacuum means decreased boiling point for the fuel. So, if the fuel sock is partially or fully plugged, it could increase the vapor lock situation. So, today I plan on testing.

According to the FSM, I need to "T" a vacuum gauge just before the mechanical fuel pump. Then operate the engine at 1500rpm and monitor the vacuum reading. It should not exceed 3" vacuum over the course of 30-seconds. In addition, I plan on placing a clear fuel filter right before the "T" for the vacuum gauge. I want to see if there are any bubbles indicating a pinhole leak in the fuel lines.

I will post up my findings. Like I said above, ultimately, I want to fix the underlying problem. But, regardless, I think I am still going to switch over to an electric pump. If I am going to keep this, it needs to be 100% reliable. From everything I have read on numerous forums for numerous vehicles, the underlying recommendation is that a mechanical will work...but an electric is a bit better.

1. I ran a new hose from where the steel line ends at the frame, and snuck it up to where the steel line outputs from the old mechanical. I cut the line at that point and clamped the hose onto it. I left the OEM fuel filter in place.

2. Rotary is quieter than solenoids (rotaries whine; solenoids chatter) and there's nothing to wear out EXCEPT tolerances if you fail to install a filter on the input to the e-pump. A clear filter is preferred simply because you can peek under once in a while and inspect it for debris. If the solenoid design does not utilize a diaphragm, then I can't imagine how it works. Something has to be reciprocating.

3. Can't speak to delamination. I have the original tank and no problems. But I cannot imagine aftermarket tank manufacturers knowingly putting out a tank that is dissolved by ethanol.

If you have any pinhole leaks, installing an e-pump will reveal them in a heartbeat (and a sniff or two) because you're now pushing fuel under pressure from the tank instead of sucking it out from up front.

OEM mechanicals are very reliable insofar as sucking up and pushing out a long time. But the objective is a reliable fuel delivery system which needs to take into account ethanol-induced vapor lock, metal and hose line deterioration and pick-up tube sock blockages. In fact the more its blocked, the higher the chances of vapor lock as the mechanical struggles to suck the gas up, lowering the gas vapor temp even more. The design engineers did not envision that 30 years later we'd be starving 3rd world people in favor of stuffing corn gas into the gas hog tanks. So in essence it IS a design problem, but one that developed after the fact.

If e-pump reliability still makes you nervous, get a cheapo-type spare to carry. That, plus a few tie wraps ought to make it a 10 min job on the road. And if course, its assumed that like all smart FSJr's you stash at least a minimal tool kit under the seat or in the rear well.

[serehill]

You're on the right track

I think I am ultimately going to go to an electric Holley Red Top...but want to fix the issue first. It is a bit long...but I have 3 big questions.

1) How do I plumb this in on the carburetor end? The hard stainless line screws into the mechanical pump. If I eliminate the mechanical pump...how is that steel line supported??

2) Is a Rotary Vane (Carter/Holley) better than a Solenoid (Carter/Airtex)? Everyone seems to like the Rotary Vane design...but the Solenoid design is not supposed to have any rubber diaphragm that gets deteriorated by ethanol.

3) Anyone have issues with fuel tank delamination? I have the stock plastic fuel tank...I know some brands of plastic tank have had issues with delamination due to ethanol.

Below is a brief history if you want/need to read...

The shop swears they have fixed the issue...they said it was just out of gas. They filled the tank (with 5-gallons) and said all was right in the world. Last time I knew...we had a 20-gallon tank. Seems odd that I could only use 1/4 of it. So, I am not overly confident the issue is repaired.

Last summer (about a year and a half ago) I replaced the fuel tank strainer / sock / whatever you want to call it. I noticed some large black flakes in the tank. Cleaned them out as best I could. Ran great for about a year. Then this last July I started getting issues with fuel delivery. Not sure if it was starvation, vapor lock, or what. I have replaced all rubber lines, new fuel pump (mechanical), new fuel filters, carb rebuild...the problem would seem to go away for a short time and then return.

I have verified that the fuel pump works within spec (both pressure @ 6.5", vacuum @ 12", and supply). And I have verified that the fuel filter works. The only thing I haven't checked is the fuel tank strainer / sock. It dawned on me a couple days ago that if this thing is plugged, it would increase the vacuum that the supply line is under. Increased vacuum means decreased boiling point for the fuel. So, if the fuel sock is partially or fully plugged, it could increase the vapor lock situation. So, today I plan on testing.

According to the FSM, I need to "T" a vacuum gauge just before the mechanical fuel pump. Then operate the engine at 1500rpm and monitor the vacuum reading. It should not exceed 3" vacuum over the course of 30-seconds. In addition, I plan on placing a clear fuel filter right before the "T" for the vacuum gauge. I want to see if there are any bubbles indicating a pinhole leak in the fuel lines.

I will post up my findings. Like I said above, ultimately, I want to fix the underlying problem. But, regardless, I think I am still going to switch over to an electric pump. If I am going to keep this, it needs to be 100% reliable. From everything I have read on numerous forums for numerous vehicles, the underlying recommendation is that a mechanical will work...but an electric is a bit better.

I would highly reccomend vane a opposed to diaphram period.
Never seen the delamination. I'm thinking it's mold overcast parts. The tank is built in one casting so delamination would be rare.

I think the mechanics history is a bunch of Bull.
There are several threads on this subject running now. The system is only as good as the quality & sum of it's parts. Please consider the entire system. I would not convert back to manual for anything. I don't think the AUTOMOBILE industry will either. The diesel industry the boating industry maybe. But we aren't talking about those.
Your findings would be much appreciated although a search will show positive results over & over. The only negative results I've ever seen is from either bad installs or mitigating other issues. If done correctly & all of your system is good this is a positve mod. Just my opinions but there's a lot of other responses that concur.

[twmattox]

Hey, thanks for the input. I picked the rig up from the mechanic and barely made it home. Even with a full tank, this thing is falling flat on its face. I KNEW the problem wasn't fixed. I agree that these things should operate just fine with a mechanical...so, I need to find the problem before I upgrade to an electric pump.

Again, thanks for the input on the fuel pumps. I have it narrowed down to the Airtex E80120S (around $50) or the Holley Red Top (around $120). The Airtex is a solenoid design and the Holley is a rotary vane. I want the most durable reliable and least prone to failure I can get... I went to the Federal Mogul website to research fuel pump design. They manufacture both the solenoid and rotary vane design. Here is what they say:

http://www.federalmogul.com/en/AftermarketSolutions/EMEA/EngineSolutions/Products/CarterFuelDelivery/CarterElectricFuelPumps/Solenoid/

http://www.federalmogul.com/en/AftermarketSolutions/EMEA/EngineSolutions/Products/CarterFuelDelivery/CarterElectricFuelPumps/RotaryVane/

The interesting thing to me is that the solenoid kind has no internal rubber parts... Rich88, I agree...I don't understand how it works without a diaphragm.

[Rich88]

Hey, thanks for the input. I picked the rig up from the mechanic and barely made it home. Even with a full tank, this thing is falling flat on its face. I KNEW the problem wasn't fixed. I agree that these things should operate just fine with a mechanical...so, I need to find the problem before I upgrade to an electric pump.

Again, thanks for the input on the fuel pumps. I have it narrowed down to the Airtex E80120S (around $50) or the Holley Red Top (around $120). The Airtex is a solenoid design and the Holley is a rotary vane. I want the most durable reliable and least prone to failure I can get... I went to the Federal Mogul website to research fuel pump design. They manufacture both the solenoid and rotary vane design. Here is what they say:

http://www.federalmogul.com/en/AftermarketSolutions/EMEA/EngineSolutions/Products/CarterFuelDelivery/CarterElectricFuelPumps/Solenoid/

http://www.federalmogul.com/en/AftermarketSolutions/EMEA/EngineSolutions/Products/CarterFuelDelivery/CarterElectricFuelPumps/RotaryVane/

The interesting thing to me is that the solenoid kind has no internal rubber parts... Rich88, I agree...I don't understand how it works without a diaphragm.

I read the fine print on the solenoid one and they said it uses a piston. I'd say that's better than a diaphragm, but you can't have a piston without moving parts subject to wear 'n tear.

Here's another for consideration from the same website. Didn't do a price search though.

http://www.federalmogul.com/en/AftermarketSolutions/EMEA/EngineSolutions/Products/CarterFuelDelivery/CarterElectricFuelPumps/CarotorGerotor/

[babywag]

I have used a Holley red top, not to loud, and worked very well.

When you replaced the sock, was the old one intact or had it fallen apart?

Sounds like you may have a blockage problem.
This would jive with it working sometimes, and other times not.

If it were mine....
Remove fuel sender and check for debris in the tank. From old sock or whatever.
Blow compressed air through fuel lines from engine towards tank.
Again check for debris.
If you find anything that was/is your problem.

Are you running a fuel filter before the fuel pump?
Should be done especially if you saw debris in the tank before.
A clear plastic filter is a good idea on the soft line from the hard line to the mechanical pump.
Doesn't take much for a little chunk of junk to mess up the mechanical pump.