Hello! So here's the story... (Vehicle: 1990 4runner 4x4 L4 2.4L 22re)

When I was out of town last week when I was 200 miles into a tank (fuel gauge doesn't work) I started getting some hesitation in my acceleration. I topped off the tank and replaced the fuel pump because I installed a cheap one in mexico and did a bad job. (Stripped wires badly and crimped loosely). I drove back home which was 6 hours with no issues. (Never went over 200 miles on a tank on the way back)

When I got back home I figured out the pinging issue I had while accelerating. The PO had the timing advanced to 12 degrees, so I dropped it down to 5 degrees and it got rid of the pinging (car was jumped when I adjusted/checked timing) I drove it around 20 miles and it ran great, def drove differently, but still drivable. When I was driving back home I started getting the same issues when I was out of town (hesitating while accelerating, almost stalling out going from stop to 1st gear). I thought it had to do with the timing so I re adjusted the timing to 8 degrees and it worked for a second then I realized I was near the 200 mile marker for my tank of gas. I filled it up, and no more issues with accelerating.

I researched on this forum to see what could be causing that issue. I think the slosh tank pipe had some stuff clogging it (saw crud at the bottom of the tank when replacing fuel pump) so when I was low on gas, I assume it couldn't get gas fast enough when cruising/accelerating. I did some research, and put some Starbrite Startron gas tank cleaner in there. Used the proper amount of cleaner and let it sit for 24 hours.

I drove it around for around 40 miles to clear out the tank. I was getting some hesitation then, but I was expecting it because on the bottle it says keep extra fuel filters handy because it can clog it. I replaced the fuel filter (old filter was clogged) and it drives great around town. But when I was driving 10 miles away up a hill, it felt bogged down, it had light surge in power, and I had to go down to 2nd gear on this hill when I can usually go up it on 4th. Also going from stop to 1st, I really gotta push the gas so I don't stall out, and when my car warmed up, the exhaust was definitely louder (not sure if its all related) Pretty much the same issues I was having at my tank with 200 miles on it, but this time it only has 150 miles to the tank

Here are the parts I put in the car the last 6 months that relates to this issue...

New NGK spark plugs (8k miles on them, also don't look too bad)
New Spark plug wires (1 week old)
Distributor cap
Fuel Filter
Fuel Pump
New Fuel injectors
Checked for vacuum leaks with starter fluid (Didn't find any)
New PCV valve
Cleaned out throttle body
Checked TPS and adjusted accordingly
Sprayed MAF sensor with proper spray
Checked EGR (sucked in on one of the hoses and it stalled out my car)
No Check engine light
Disconnected the cat converter, had more power, but still a slight surge in acceleration (didnt remove all the way, just unbolted 2 bolts)
Starts and idles great

Anyways tomorrow I'm going to check my fuel tank to see how it looks in there with the cleaner and make sure the fuel pump still looks good

My question is.. is it a timing issue? Or is it a coincidence that other things are coming up after changing the timing? Because after I changed the timing, more issues seem to be coming up.

Any idea? Thanks in advance!

 

Fuel pressure regulator

 

Also, check that there's good fuel flow at the FPR. Put a clear hose in place of the return line, and put it into a container to catch the fuel. Use the jumper to run the fuel pump for 30 seconds. You should get about .5 liters in 30 seconds. If you get much less than that, you've still got crud clogging the fuel lines someplace.

Also, as said, check/replace the FPR.

Good luck, and let us know how things go for you...
Pat☺

 

Awesome thanks for the suggestions! I'll check the fpr either today or tomorrow

 

Installed a new fuel pressure regulator.. still same symptoms. Almost stalling out when trying to accelerate and still hesitation.

Also after test driving the new FPR with no different results I checked my fuel pump again, everything seemed in order, but when I tried putting the fuel pump assembly back in it wouldn't sit back straight flush easily (Where there is like 8 philips head). Then when I tried to start the car it was having a hard time starting, also I took a picture of inside my fuel tank. Does the slosh tank look crooked?



Any other ideas? I will borrow my buddies fuel pressure kit probably next week

 

The pressure is important, yes, but so is the volume. The amount of fuel flowing past a given point in a given time. That's why I suggested the clear hose on the FPR fuel return port, and so on. That won't tell you the pressure is correct, but it WILL tell you whether the volume is correct.
Having said that, generally, if the pressure isn't correct, the volume won't be either. The two are inter-related. Got to have enough pressure to push the volume.

The pulsation damper on the inlet to the fuel rail may be clogged, or the diaphragm in it may be broken. If it is, it may not be allowing enough volume into the fuel rail if the diaphragm has failed.

Just throwing out ideas. I hope something may help...
Pat☺

 

I realized that I had a vacuum leak in my main intake hose (the one connected to the throttle body) near the upper radiator hose. Whenever I disconnected it to try to depressurize the fuel system by stalling out my vehicle I realized I had been making it bigger and bigger to the point where my car doesn't want to idle anymore.

Got the part ordered and it will be here Thursday, I'll update when I get it installed!

 

Hmm still having issues accelerating..

Checked the fuel pressure. With just the fuel pump running Im getting around 41 psi and when I open the throttle I'm getting around 35psi. I also checked the flow of the fpr, and it was spraying like crazy when I started the car.

but I realized when I put more gas in the issue is getting better. If Im above half a tank when I open the throttle it doesn't seem like it struggling, but when I drive and put it into gear it's still running super rough

 

Check the wires on the distributor are in 1-3-4-2 order.

 

Yeah I double checked that after I did a compression test