Something to be said about simplicity

[dodgerammit]

So, Date night attempt #2 in the Waggy proved to be a no-go due to the electric pump intermittently losing pressure causing lags/surging upon acceleration.

Swapped in a new pump to replace the 2 month old unit.

Verified it was the old pump, but now idle was all over the place once again.

P.O had stated the mechanical pump wasn't up to the demand of engine, so that was why the electric was there.

Just out of curiosity, I decided to swap a new mechanical in place. The old one might have just been worn out.

Problem solved! A tiny adjustment of the idle screw and she's running like a top again. And, I have the spare new electric pump in the back 'just in case' the mechanical one catastrophically dies and I need to make it home.

[letank]

Good, do you have the name and type of the failing e pump, or a pict(s)

[ghcoe]

It might supply fuel now, but during the summer once the engine and surrounding areas heat soak I bet you will have a problem. I fought my issue for 2 years and finally put a electric pump on it and no more problems with fuel demand. Finding good electric pumps is another story. My first pump was a Holley Red because everyone raved about them. Well it failed within the year. Started to leak at the weep hole which is not repairable with their repair kit. Only a three month warranty so I was out of luck on a $125.00 pump. Found a Precision pump at the local Oriely for a lot less and it has a lifetime warranty on it.

[dodgerammit]

Ironically, the precision pumps are what I've had the bad luck with. Just returned the bad one to Oreilly's. I'll wait and see come summer. It was 90* today. No problems so far. If I have problems with the mechanical, I'll try to figure an in tank tbi unit with a pressure regulator on it.

[will e]

If the mechanical pump fails check the oil for gas.

[ghcoe]

Ironically, the precision pumps are what I've had the bad luck with. Just returned the bad one to Oreilly's. I'll wait and see come summer. It was 90* today. No problems so far. If I have problems with the mechanical, I'll try to figure an in tank tbi unit with a pressure regulator on it.

I switched out the mechanical pump twice due to vapor lock on hot days. I have 25 mile commute one way. On the way home, on a hot day 95+, it would run great for about 15 miles on the freeway and then would start to act up. When I had the Jeep running 15 years ago it never gave me any trouble, even pulling a 5500lbs trailer. It was driving me crazy. People were pointing to crappy China pumps, but I doubted that. I started to dig further on some hot rod sites and they were talking about how crappy todays fuel is compared to what the older vehicles where designed around. With the advent of FI the need for higher fuel boiling point went away. Made sense to me and sure enough, added a electric pump and no more vapor lock. Most people think vapor lock occurs between the pump and the carb. It actuality occurs between the pump and the fuel tank. That is the benefit of a electric pump by the tank. Even though it does not produce any more pressure than the mechanical it is pushing the fuel from the tank forward instead of trying to suck fuel forward. Which if the fuel turns to vapor no pumpy....

[ghcoe]

Oh, which pump did you have. I purchased this pump. http://www.oreillyauto.com/site/c/detai ... +universal . It had a pretty good review as the carter version. I guess time will tell.

[dodgerammit]

Ironically, the precision pumps are what I've had the bad luck with. Just returned the bad one to Oreilly's. I'll wait and see come summer. It was 90* today. No problems so far. If I have problems with the mechanical, I'll try to figure an in tank tbi unit with a pressure regulator on it.

I switched out the mechanical pump twice due to vapor lock on hot days. I have 25 mile commute one way. On the way home, on a hot day 95+, it would run great for about 15 miles on the freeway and then would start to act up. When I had the Jeep running 15 years ago it never gave me any trouble, even pulling a 5500lbs trailer. It was driving me crazy. People were pointing to crappy China pumps, but I doubted that. I started to dig further on some hot rod sites and they were talking about how crappy todays fuel is compared to what the older vehicles where designed around. With the advent of FI the need for higher fuel boiling point went away. Made sense to me and sure enough, added a electric pump and no more vapor lock. Most people think vapor lock occurs between the pump and the carb. It actuality occurs between the pump and the fuel tank. That is the benefit of a electric pump by the tank. Even though it does not produce any more pressure than the mechanical it is pushing the fuel from the tank forward instead of trying to suck fuel forward. Which if the fuel turns to vapor no pumpy....

I also avoid anything ethanol like it contains the black plague. I despise anything less than 100% gas.

[dodgerammit]

Oh, which pump did you have. I purchased this pump. http://www.oreillyauto.com/site/c/detai ... +universal . It had a pretty good review as the carter version. I guess time will tell.

I had this one.
http://www.oreillyauto.com/site/c/detai ... +universal

[letank]

Oh, which pump did you have. I purchased this pump. http://www.oreillyauto.com/site/c/detai ... +universal . It had a pretty good review as the carter version. I guess time will tell.

similar to the carter P4070, which is what I have been using for the last 15 years... last about 10 years or a little more...

[dodgerammit]

I'll keep that info on reserve, should I need it. Thanks

[ghcoe]

Oh, which pump did you have. I purchased this pump. http://www.oreillyauto.com/site/c/detai ... +universal . It had a pretty good review as the carter version. I guess time will tell.

similar to the carter P4070, which is what I have been using for the last 15 years... last about 10 years or a little more...

I bet it is the same pump just different box. I did not see any markings on the pump, but it looks exactly the same even the extras.
Carter:
https://www.summitracing.com/parts/crt-p4070
Precision:
http://www.oreillyauto.com/site/c/detai ... +universal

I hear you on the non ethanol fuel except when traveling it can be inconvenient. Glad you had a different pump, it gives me hope....

[letank]

I hear you on the non ethanol fuel except when traveling it can be inconvenient.

I am in Cal, and ethanol is present at any gas station... This is why I carry a spare...

[dodgerammit]

http://pure-gas.org/ When I travel, I always check here to plan my routes.

[dodgerammit]

Just an update. Had a date night tonight and lo and behold, about 10 miles into the commute, got the surging, then wouldn't run faster than 45 mph. Throwing the trans into neutral gave me my throttle back after a few seconds. Once back into gear, however, it would do the same. Pulled over and let it idle, and the problem went away.... for about 1/2 mile.

It died as I pulled over the second time.

I have 2 filters on the fuel line. A clear one before the mechanical pump and the common metal one with the return after the pump. Sure enough, the clear filter was dry inside.

A couple of attempts, and she started, thankfully. After the restart, I let it idle for a couple of minutes and we hit the old highway (speed limit 45 and under) for the rest of the trip.

Lemons make lemonade, though.
Actually ran across a benefit carnival on the way home (something we would have missed on the main route). We rode rides like little kids again.

At the lower speeds, there were no issues.

Temps were low 80s, but the first 5 miles were stop and go city driving. About 4-5 red lights. Nowhere near low on fuel. Probably had over 3/4 of a tank. Have only driven about 30-40 miles since fill up.

So, I either have vapor lock or the pump just can't supply at that speed (which I doubt given I have driven it at 55-60 non stop for well over 45 minutes).
Either way, there is a lack of supply for the demand. Something a pusher setup should remedy.

I'm looking at installing the better style electric. For those who run it, where have you mounted yours? Advice? Required extra install pieces?


Thanks

[shimniok]

Maybe it isn't the pump or vapor lock. Many things can cause fuel starvation and resultant lean surging.

I can't think of every possibility but generally any obstruction from the pickup sock to the carb bowl and all in between needs to be able to flow freely. I might also want to know if the gas tank can easily draw in air to replace the fuel being used.

Fun fact, some FSJs just aren't prone to vapor lock problems. Some are.

The two I've had almost never had an issue. But I've had lean surging due to an unknown carb issue and fuel regulator inline.

Sent from my XT1096 using Tapatalk

[dodgerammit]

I've blown through the pickup line and know it is free of obstructions.

I was in the tank at the beginning of these issues and all looked good. No sock, just a basic screen on the pickup tube.

Where does the tank draw air in from? I'll check that next.

Thanks

[ghcoe]

Your tank should draw air in through the charcoal canister as well as vent through it too.

I still think it is the poor fuel blends. Sounds about right with the miles driven before a issue arises. That is what happened with my FSJ every time I thought I had the problem fixed. Never had a problem when driving in the early 2000's, parked it for 9 years and now has the problem. Only thing that has changed is fuel blends during that time. I tried everything mentioned to prevent vapor lock and nothing worked, once the engine bay got heat soaked it would vapor lock. Usually that was 10-20 miles down the road depending on the outside temp. Since I converted to a electric pump I have never had a fuel starve condition for a year now.

I would stay away from the Holley Reds. Mine did not even last a year. I purchased the Precision pump from O'rReilly just because it had a lifetime warranty and I have O'Reilly's all over here in case I do have a problem. I spent about $25 more for it there than for the Carter lookalike (probably the same pump) at Summit. I will say it is much more quiet than the Holley. I can barely hear this one running where the Holley was a bit annoying.

I mounted the pump just behind the fuel tank on the cross member. I then was able to run a hose from the tank out to the passenger side and loop it back to the intake side of the pump. I placed a generic Fram G2 filter in this section of hose. From the output side of the pump I ran a hose to the drivers side and then looped it back over the top of the tank and connected it to the steel fuel supply line that the tank hose would normally attach to.

I ran a 10 Ga. wire from a installed relay back to the pump. You may think that is overkill, but a low voltage signal will destroy a pump. You want as much current available as it will consume for a happy pump life. Running wire long distance and with high draw can heat wire up and then it compounds on itself. More heat creates more resistance which with power draw creates more heat. The relay now is just connected to power "on" from the coil. Ideally you want to get the oil pressure switch for more safety. Make sure you run a 10 Ga. wire to the relay also.

Good luck George.

[dodgerammit]

Mine no longer has a charcoal canister. I still think it is a vapor lock condition since it only started doing this when temps went into the 80s. It also has fired back up after some fuss this last go around, but I made sure to drive a slower speed (requiring less throttle) and took another route. It happily ran 45 with no fuss, but after a bit of 55 mph driving, is when it lost throttle response. I can say without a doubt no fuel was in the clear filter ahead of the engine mounted pump. After firing up again, it was a small stream. After idling awhile, it was pretty full again.

I'm going to mod my factory sender like the tbi guys do and put a low pressure pump made for the ford trucks in the late 80s.

https://shop.advanceautoparts.com/p/car ... 7CL3*15378

It is in stock, specs 4-6 psi and flows 20-35 gph.

I would rather be able to pop the access panel under the rear seat and simply access the pump that way than have to crawl under a vehicle on a rainy night off of the side of a muddy, gravel road (cause we all know how Murphy works).

[ghcoe]

Sounds good. I think you will be happier with a quality electric pump no matter where it is mounted. Good luck.