Stuck in Albuquerque fuel problem. Injection,dirty tank, fiuel filter

[djw40d@yahoo.com]

A mor detailed idea of my problem left Chicago the car was hesitating on highway slightly. So when I filled up and added injection cleaner, that helped. Drove to Springfield then to st Louis pretty easily, took the tank to 1/2 tank and got a big hesitation, so I filled up added a little more injection cleaner next morning I drove off to Amarillo car was ok off to Albuquerque got there and pulled off at 1/2 tank for fuel and serious hesitating refueled car ran normal getting on highway. Drove 45 46 miles and I got a constant every 5 seconds choking at 60 mph so I got off and had car towed to Sandia BMW. They will look at it Monday looking around I spotted a 73 2002tii showroom ready I was told that it belonged to the owner of the dealership, so at least one person there knows our passion. So I'm stuck in Albuquerque till Monday any other ideas ?

[cpolyak]

Curious what your plugs look like. If you pull them, and they're fouled, it could have something to do with altitude. The car was in Chicago if I recall from the BAT listing. . . sea level. At the ~5000' you're at in Albuquerque, there's less air so the air/fuel ratio could be rich. I had this issue with my 73tii a few weeks ago here in Denver. Advance should be checked too. 

 

Good luck. 

[OriginalOwner]

my absolute worst guess:  electric fuel pump is failing.

 

Cheers,

 

Carl

 

[Adamha]

Rule out fuel delivery to the pump. Pull the hose after the filter that feeds the pump. Get a jar, bottle, ect. Search the forum for how much fuel should end up in the jar when you energize the system over a certain time. If it meets spec, you can rule out pump, pickup screen and fuel filter. There is a small inlet screen on the pump that you can clean easily also. Right where the main fuel in connects. I would rule those things out first.

 

Then go to ignition.

 

If it's pump or injectors, you are trailering. No quick fix. But it's most likely not pump or injectors. My guess is a ton of crap in your tank and a clogged fuel filter.

[Swiss 2002Tii]

Sorry DJW, clicked the red down arrow not recognising as the "not like"button.  Hope you find you problem!

[Swiss 2002Tii]

I agree with cpolyak regarding the altitude...check points gap and timing.

[jgerock]

It could be the fine mesh screen on the bottom of the pickup inside the tank. When you refill, the flow of fresh fuel can wash the crap away from the screen, allowing the pump to pull again for a while.  Starving the system multiple  times could cause pump failure.

[gregpark]

Your problem could also be water in the tank. Ethenol laden gasoline attracts water. I recently experienced this problem with my Jeep. Old gas in my Jerry can. If you live in an area where ethanol is added to fuel, it should be used within a couple of months.

[JerryC]

5 hours ago, gregpark said:

Your problem could also be water in the tank. Ethenol laden gasoline attracts water. I recently experienced this problem with my Jeep. Old gas in my Jerry can. If you live in an area where ethanol is added to fuel, it should be used within a couple of months.

Ditto - old fuel is bad. Just last month, my friend's boat had a similar problem after sitting less than half full for 5 months. Unfortunately, this came to about 80 gallons of bad gas, and he was faced with a high disposal cost to just get rid of it. His research came up with information about "phase separation". To fix it, he siphoned about a quarter of the old gas out from the bottom of the tank until the engine ran reasonably well again. He then filled the tank up to the top, adding Stabil this time, and all was well again. Phase separation is apparently aggravated by low fuel level allowing condensation to collect inside the tank. Modern gasoline-based fuel is becoming more and more difficult to manage.

[PaulTWinterton]

8 hours ago, jgerock said:

It could be the fine mesh screen on the bottom of the pickup inside the tank.

 

+1

 

Higher rpm hesitation points to this.  The pump cannot suck the amount of fuel required because of the restriction at the tank.     

 

Cpolyak,  good call.   Though AFAIK air/fuel ratio richness at higher altitude causes poor running throughout the rpm range.  Easiest to eliminate the tank screen and other screens first, before messing with your AFR setting.  Especially since the car is at a dealership.  Checking the screens is something they can't screw up too easily.

 

Good luck.  I feel for ya.

[cpolyak]

@PaulTWinterton, didn't catch the "high RPM hesitation" symptom. Yes, pulling the pickup and checking the screen would take <5min and should be a quick inspection. Same goes for the plugs. A few minutes can tell you a whole lot. Provided that the OP has basic tools, you could easily tackle these two inspections. 

 

 

Edited May 14, 2017 by cpolyak
typo

[ray_]

3 hours ago, cpolyak said:

@PaulTWinterton, didn't catch the "high RPM hesitation" symptom. Yes, pulling the pickup and checking the screen would take <5min and should be a quick inspection. Same goes for the plugs. A few minutes can tell you a whole lot. Provided that the OP has basic tools, you could easily tackle these two inspections. 

 

 

 

 

THIS!

 

As stated multiple times, by multiple people. All of which have probably been there, done that!

 

 

[2O=00=O2]

Quote

 took the tank to 1/2 tank and got a big hesitation, so I filled up added a little more injection cleaner next morning I drove off to Amarillo car was ok off to Albuquerque got there and pulled off at 1/2 tank for fuel and serious hesitating refueled car ran normal getting on highway.

 

Is you symptom of always at half tank consistent when it happens or was the last problem with a full tank too??

If so is there any possibility that there is a fuel pick up tube issue?? I heard of problems on other cars with pick up tube cracking or breaking off..................funny thing is my John Deere 322 has a broken off pick up tube and hesitates and surges at half tank or leaves me stranded as far away from the garage as possible when it quits LOL.

 

Me I'm guessing fuel supply restriction (filter) or fuel pick up below half tank. (pick up tube or filter in tank or water/contaminates)

 

Mike 

[thehackmechanic]

Any tii that's been sitting is subject to both the fuel going to shit and to the tank rusting and the rust clogging up the filters. It is also certainly possible that the car either has water in the gas or got a tank of bad gas, but bad fuel and rust from sitting are more likely.

 

If I had the car here, I'd:

 

--First check the dwell and timing and verify that each cylinder has spark. I'd probably install new freshly-gapped plugs and drive the car just to rule that out. 
--Remove the pickup tube from the gas tank and look in the tank with a flashlight. If there's visible rust or sediment, drain the tank and clean it. You can actually get them pretty clean, certainly way cleaner than they had been, without removing the tank; just use brake cleaner, rags, paper towels, and run gas out the drain plug.

--Inspect the screen at the bottom of the pickup tube, and make sure both the delivery and return pipes are clear. I've seen both completely clogged up with tarry crud.

--Remove the fuel pump and tap the inlet out onto a clean paper towel to inspect for sediment in the inlet screen. If there's no screen there at all, and if the tank is rusty, I'd replace the fuel pump, as it's probably loaded with rust inside.

--Replace the canister fuel filter at the radiator.

--Check the fuel screen at the Y-fitting at the front of the KFish pump.

--Check the fuel pressure. It should be 29 psi. If it's noticeably low, the fuel pump may be at fault. If it's noticeably high, the pressure check valve at the back of the KFish pump may be at fault. The pumps usually work fine until they stop working altogether.

--Reassemble and test.

--If the problem hasn't gone away, if the tank wasn't drained before, I'd drain the tank and try it with fresh gas.

--If the problem still hasn't gone away, I'd begin looking at the injectors. When I trouble-shot Brian Ach's car that died on the way to The Vintage two years ago, even though it had rampant fuel system contamination, the root cause was in fact a broken spring in #4 injector. I found it by pulling all four injectors out and disassembling them. They all were loaded with rust, but #4 had the broken spring. Once I found that #4 was bad, differences I was seeing in how the fuel appeared to flow through #4 plastic line made sense -- #4 looked different and the pulsing of the line felt different than the other three. I'm not, however, sure how reliable a diagnostic tool that is.

--The KFish pump itself is the last thing to suspect, not the first.

 

Good luck!

 

Rob

 

 

[TobyB]

To Rob's first point, don't underlook plug wires and condenser in this whole equation... very easy to rule out.

 

t