Charecter1

okay guys, so i posted a thread on here a while back about a problem im having with my 4runner. i am still having the issue but now i have more information on it so maybe you guys can help. its a 1993 3vze automatic with 211,000 miles and cold air intake. 33 inch tires and a 5 inch lift. so this is whats happening, the truck is set at about 17btdc right now because its really the only way for me to drive it. when i set it to its factory 10btdc, its hard to start and stumbles and will have no acceleration what so ever. at 17btdc it starts fine but after driving a couple of miles, it falls flat on its face and even at full throttle, it takes a few seconds to do anything, it feels like im slowing down when i full throttle. as soon as i turn the truck off and turn it back on, it runs fine again for a couple of miles. i just replaced the plenum gasket and pcv, dist, rotor, plugs, fuel filter, wires and throttle body gasket and adjusted the tps. it helped some but its still failing on me. i checked for vacuum leaks and found none. i did a fuel pressure check and it read normal at 17btdc but when i changed to 10btdc the needle would bounce really fast between 35 and 40 psi. the pump does make a screeching noise but pressure seems fine so i really cant decide what this is. its also not throwing any codes.

wyoming9

iTrader: (1)

Have you changed the fuel filter lately Unless you didn`t list that.

Charecter1

sorry i forgot to put that, i did change the fuel filter about a week ago.

wyoming9

iTrader: (1)

Have you looked for crushed / kinked fuel lines

Could some thing be causing the Circuit opening relay to drop out ??

The needle bouncing could just be your gauge.

Your sure it is an engine problem and not transmission ??

Are you in the habit of driving on empty ??

Charecter1

I just bought it and haven't driven it on empty but I don't know if the other owner did. When the rpms do kick it, the truck will do what its supposed to and its fluid is good and the od light flashes so it has no codes.

scope103

Did you follow the correct procedure to set timing? If you didn't use the jumper, the timing is almost certainly mis-set.

Charecter1

The jumper as in the timing light tool?

Charecter1

Sobi was driving it tonight and tried full throttle and it lost all its power and almost died on me, when I let go of the gas it came back to life.

Terrys87

iTrader: (1)

You need to use a paper clip, to jumper TE1/E1 the picture below is for demonstrating purposes with the wire. I dont know the 3.0 but the fuel pump has a filter on the end of it as well and I have seen them get a hard varnish like shell on the end of them that can impede fuel flow.


This picture is from a 22r carburated model but shows the same thing as what could be possibly slowing the fuel flow. The filter on the end of the pickup tube had one area for fuel to get thru. Another problem I see alot of is the fuel system is in bad shape. Return lines clogged starting from the back of the motor all the way back to the fuel sending unit, gas tanks have a lot of nasty build up inside of it. The tank can be cleaned or replaced and the fuel lines I flush with PB Blaster.

Terrys87

iTrader: (1)

I havent worked on a 2nd gen runner in a long time, but under the passenger rear seat, you should have an access panel that you can remove the screws to and get to the fuel pump assembly. A lot of times the supply line to the fuel assembly can be frozen and difficult to seperate. Use caution on working on the assembly as not to kink or break the metal line to it as that assembly can be expensive and hard to find.

You should have enough slack in the fuel lines to lift the fuel assembly out and look at your filter and see the condition it is in.

Charecter1

Thanks for the advice, I'll work on trying to replace the fuel pump this weekend. But I'm also wondering if it could be a bad coil.

scope103

Uh, no.
Here's the manual. http://personal.utulsa.edu/~nathan-b...13distribu.pdf

Since your timing is almost certainly mis-set (and would be the obvious cause of your symptoms), that's where I would start looking. Not too hard to check.

Long before I messed with the fuel pump.

Charecter1

So update on the truck, I used a paper click to jump the wires (although I don't know how that would make a difference in timing) and set it to 10btdc. As soon as I gave it gas it tried to die on me and make a loud thump sound from the engine and then backfire.

Charecter1

I also can barely get it to 10btdc, I have to turn it as far as I can to even get it close to 10btdc and the bolt has to come off to get it any lower than ten

wyoming9

iTrader: (1)

Sounds like the distributor might be off a tooth or more.

Because the ECU controls the advance of the timing it must be jumpered like in my day when you disconnected and plugged the vacuum advance on the distributor to adjust the timing

Charecter1

I cranked the engine to 0btdc and checked the rotor and it was where it was supposed to be, so I don't think timing is my issue

Thehollywood811

I have a similar problem also, my truck will have less power then normal during acceleration and when starting from a stop will sometimes want to die and I'll have to pump the pedal and rev it and it will backfire and pop and come to life and be normal it's sooo annoying and I replaced plugs wires cap rotor ignitor coil fuel filter injectors tps etc... I was thinking it was maybe a fuel pump or maf also. I'm checking my timing tomorrow to see where that's at

Charecter1

Did you ever figure your problem out?

Thehollywood811

No i advanced my timing from 10 to about 13 and it runs alot better but i think it's just masking the problem. I did notice that it runs worst with A/C on if that matters..

RJR

Those are classic symptoms of a bad TPS. Among other things, the ECM uses the TPS signal to know when to dump in more fuel to prevent stumbling during acceleration.

Check the TPS using this FSM link.
http://personal.utulsa.edu/~nathan-b...34throttle.pdf