ParkerG

Ive been working on my 94 4runner for about 2 months now and have put well over 30 hours $1600 into it, but still have the same problems i have been having with it. Is anyone willing to step by step help me figure out whats going wrong??

ParkerG

Overheating on freeway, temp gauge bouncing when engine is hot or rpm is over 3k.
Poor gas milage and power. 8mpg.
Does not start on first try.

Terrys87

iTrader: (1)

I don't know the 3.0 but how clean is your cooling system and what kind of condition is it in. Timing belt and timing sit right? Catalytic converter clogged? All sensors clean and working? Vacuum lines clear of carbon, routed right? Water pump and fan clutch functioning correctly?

Janos01

Have you done a tune up lately (replace Cap, rotor, plugs, wires and oil)? Changed out the air filter, cleaned throttle body, cleaned battery contacts?

What all has been done and what year & model is your toyota?

ParkerG

Ive done timing belt, water pump, spark plugs and wires, vacuum lines, cat muff and o2 sensor.

Janos01

Have you checked the ignition coil, starter, cold start injector?

ParkerG

Starter is good, coil is good, still need to check cold start with volt meter though.
How likely could is be a fuel pump/filter issue, i ran the b+ to FP test and pump functions.

Janos01

When the car starts, does it run like it does not have enough fuel or does it idle fine?

RJR

What do you mean by "doesn't start on first try"? Won't turn over, or turns over but doesn't fire, or fires but doesn't keep running? We need more information.

Is the check engine light on? Are there any diagnostic codes? Does the CEL work? (Should come on when you turn the key on before you try starting it).

8 mpg, low power, and overheating either indicate something messed up with the engine control system, which should throw a code, or a mechanical problem with the engine such as a blown head gasket or burned valves. I would run a compression check on all 6 cylinders. Do a leak-down test on any bad ones to find out where it's leaking. You can also get a kit from Autozone, etc., to check for exhaust gases in the coolant (head gasket problem).

ParkerG

Throttle position sensor code is thrown when t1+e1 connected. Check engine light does not come on when in normal operation.
When engine is cold no combustion on first start, but fires right up on second attempt.
Also when engine is cold and started idle rpm will bounce up and down untill dying unless I give it some gas.

ParkerG

HEre is some more info that may help as well.
When driving, as soon as gas pedal is depressed rpms lower and engine sounds bogged down untill i depress the pedal further.
Also when i replaced spark plugs they were all carbon fouled

mick.j.becker

A couple shots in the dark here, Have you tested your cold start injector? What about the rest of the injectors? Is the air flow meter dirty? How long does the engine sit before it won't start on first try? Maybe you are losing all your fuel pressure as it sits.

Not trying to insult your inelligence here just throwing out ideas.

lunarkingdom

Mine was doing this, check your mass airflow sensor, it is a potentiometer built into the top of the box that has your air filter in it and it basically has a flap that rotates open as air moves through the passage it is in. If it is getting stuck like mine was the computer thinks the rpm is at a fixed position and the fuel will be the amount for that position. I would not have found mine but I was replacing the plugs, wires, cap, rotor and air filter and there was sand in the air filter box so when I blew it out I blew the air flap to the full throttle position and when I started it up black smoke and gas out the exhaust made it painfully obvious. Hope that helps.