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Discussion Starter · #1 ·
Somewhat recently bought a 2003 Safari, and am trying to get it running acceptably well. My commute is 50 miles each way, and the van struggles to maintain 45mph on some of the hills. It has various other issues like shuddering, and surging idle.

Van always starts right up. Had a similar issue when first bought 2 months ago, new fuel pump got it running great. A month later, started getting P0101 (MAF sensor). Replaced it, error came back next day during a spirited drive home, but otherwise van ran great for a week or so. Next the van started misfiring. Replaced spark-plugs, wires, dist-cap, and rotor. Ran well on day one, misfiring seems fixed, but power degraded again and here I am. Had my exhaust back-pressure tested today, hit 4psi when basically redlining it, but the needle didn't seem to move until basically what seemed like red-line.

Has 235,000 miles. Sometimes when Ive been on the highway a while and get off to a stop light, it will idle up and down. Used to be so bad it would stall, but now the issue is somewhat mild after all the above repairs. Also shudders sometimes when applying above average throttle.

Any suggestions greatly appreciated.
 

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I've got one in here at the shop and its doing the exact same thing! I think it needs a cat but the boss isn't so sure, so stay tuned.
 

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Discussion Starter · #4 ·
I heard that unplugging the O2 sensor to relieve back-pressure is a good test if the issue is a clogged cat. Would it be OK to drive over 100 miles thru mountain highways like this? Should I be concerned that some exhaust would be directed straight up at my floorboards?
 

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4 PSI redlining doesn't seem high so I would probably look elsewhere. Manual states 1.2psi before the cat at 2000rpm But couldn't hurt to rule it out, the difference would be instantly noticeable, no need to go 100miles.

Have you hooked up a fuel pressure gauge? Replace the connector? Replace the fuel filter?
 

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Discussion Starter · #6 ·
100 miles would be easiest, as that's a round trip commute to work. The van actually has plenty of power until I hit an incline at highway speeds. Basically, it will downshift, have plenty of power for like 2 seconds, and power will fade away, and if I really let this go on for several many seconds, the SEL will flash due to P0101. I seriously run down to 35mph on the highway on these hills. I know the van should be able to blow through these hills because it did for a month after the fuel pump, and like a week after the new MAF.

I do not know if the fuel filter was changed with the pump. I will ask my mechanic this weekend, and get it changed if not. Fuel pressure was checked after pump replacement, but I do not know at which point in the system it was checked. Which connector are you referring to replacing? The MAF connector looked good to me.
 

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Sometimes there are problems with the fuel pump connector, I'm sure your mechanic would have said something. Fuel filter is on the frame rail under the drivers seat area. Should be able to tell if it has been changed, should have been changed to keep the pump warranty(and prevent damage to new pump).
 

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Discussion Starter · #8 ·
I never made it to my mechanic, but looking at the fuel filter myself, it appears to me that it wasn't changed. I remember when the fuel pump was installed, my mechanic never said the filter was also changed. If that's the case, no big deal, mistakes happen.

Assuming it wasn't changed, should I worry that the new fuel pump is now damaged?
 

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Discussion Starter · #10 ·
If I do it myself, I should relieve pressure if I dont want to make a mess, correct? I have done this in the past on another vehicle when changing an injector by disconnecting power to the fuel pump and running the engine until it stalled. Is that how I would relieve pressure in this situation? If so, what is the easiest way to disconnect power to the fuel pump?
 

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2005 Astro Cargo 4WD
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You could pull the fuel pump relay under the hood.
 

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Discussion Starter · #12 ·
Any tips on finding the relay/connector? I'm not seeing it. Is it under something?
 

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Discussion Starter · #14 ·
I was planning on bringing a couple empty Monster cans, old t-shirts, and paper towel. Not sure I own a funnel, though I have lots of plastic jugs I could turn into one. Main concern is safety, don't want a fire to start. Think a neighbor smokes in the garage sometimes, though Im sure if he smelled gas he would at least be more careful, hopefully.

Maybe I'll just cut the tops off some milk and water jugs to catch the gas. Main hurdle now is finding the right wrench. I need my adjustable for the filter itself, seems to be 20mm or equivalent SAE. But the lines seem to be 16mm or equivalent. I do not own a 16mm wrench apparently, and oddly not finding much SAE in my possession either.

Edit: Guessing the sizes are 3/4 and 5/8. I have neither. I'm not quite motivated enough to go buy wrenches and then come back and do this. Looks like I'll have to go to the mechanic on Saturday morning and confirm if he changed it, and if not, have it done.
 

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Umm....16mm and 20mm, I believe. I had to buy a 20mm flare nut wrench from Snap-On because I couldn't find one locally. 16mm and 15mm I already owned.
 

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Discussion Starter · #16 ·
Just got it back from the mechanic. He said he was fairly certain he changed the filter with the pump, but went ahead and installed a new one that I brought to him (for free). He said the one he pulled out was clean, and gave it back to me. It looks OK to me I guess.

He had 2 suggestions for me to try. The first being the MAP sensor. This problem is basically only happening at higher elevations, so maybe the lower air density isn't being accounted for properly. This makes sense to me, and is easy and cheap enough I think to get a new one in there. Does changing this seem like a good plan?

The 2nd suggestion was possibly a clogged cat. Since I tested the pressure and it seems reasonable, the only cheap way I can think to test this is removing the O2 sensor to de-restrict the exhaust a bit. My issue doesn't manifest in the morning until 40 miles into my journey until I'm almost at work, but the issue is much worse on the way back home. Is it OK to run without my O2 sensor for 100 miles, or at least 50?

Mechanic said he checked fuel pressure (though not sure at what point in the system) and timing. Kinda curious if I should also replace the O2 sensor (is there more than one?). Current plan is probably to pickup a MAP sensor tonight and install it tomorrow, but if anyone has any other suggestions, they would be appreciated.
 

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Passenger side of the manifold, towards the rear.
 

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Discussion Starter · #19 ·
Well, I spent probably too much money on an OBD2 scanner that can display live data, and graph one sensor at a time (pathetic imo). Zip-tied it to a convenient spot to see while driving. I'll probably watch the graph for the MAF sensor on the way in tomorrow at the spot where I expect it will start losing power.
 

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1998 LS AWD Forest Green metallic
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c60 wrote:
I spent probably too much money on an OBD2 scanner that can display live data, and graph one sensor at a time (pathetic imo)
For future reference; What model scanner did you purchase?
I have been tempted several times, but have always backed out, due to not really knowing much about the various versions.
I have considered 'borrowing ' one from the LAPS a couple of times, but so far I have not really needed anything beyond the very cheap ELM328 code reader
What are others recommending for reading live data, besides the basic stuff that 'ELM..." shows when connected via bluetooth?
Rod J.
Issaquah, WA
 
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