glennjg61

I have a 91 4 Runner with a V6 3.0 I`ve been trying to get running for the past 2 months or so. It was running fine and then kept getting harder and harder to start until it would only start with throttle pressed down. I drove it one day and it ran fine the next day when and if it would start it would bearly run for a few seconds with or without the throttle pressed all the way down. I`ve put in a new fuel pump,filter, plugs, cap, rotor - nothing. Took it to a shop they said there was no spark (it had spark before) they said it was either the ECU or Distributer. Changed both - nothing changed coil and igniter - nothing finally found out it was the Volume Air Flow Meter so I changed that now I have spark but still wont start. It sounds like it wants to start but wont. The timing is good, the cat. conveter is fine, has new muffler. I`ve been told to try everything that I`ve replaced and nothing. One thing that I thought about was when I first put in the fuel pump it kept running for quite awhile but I figured it was just pumping the lines full. Now when I turn on the key I don`t hear it run so I pulled the tank again to see if maybe I hooked it up wrong but everything was fine. I can connect the fuel pump to the battery terminal at the DLC1 by the relay box under the hood and it works fine. You name I`ve tried it. Now I`m Stumped and frustrated. I`ve spent hundreds of dollars trying to get it running. Any ideas? Any help would be greatly appreciated

Kiroshu

Well alot of things have to happen for the truck to run. And alot of things are checked on and messured and checked for the engine to start....... Trouble codes? Sounds to me like theres a communication prob for fuel to the computer. Have you tried to start the truck with starter fluid? Take a vac hose of the throttle body and have someone crank it while you spray... if it runs and keeps running while you do this its a fuel problem, and something is cutting the fuel off. Injectors not operating or pump not turning on. Check fuel pump relay a.k.a "circuit opening relay." You may need to look at your air flow meter agian. check for resistance if it does not fall in spec on all ohms checks then it needs replacing..... You may need to start checking for broke wires and or ohms at the ECU....

abecedarian

I see you're trying to be thorough in the information you're writing, but do you think you could break that down a little more... maybe into paragraphs and more specific time lines?

glennjg61

I will try the starting fluid and see if that works. I thought maybe it could be the circuit opening relay I`m just not sure where it is at? My Book doesn`t tell me where it is. I`ve Checked the wires at the ECU and the ohms for the air flow meter and it was right where it is supposed to be.

abecedarian

COR is above the ECU.

abecedarian

Fuel pump should ONLY run when you turn the key and crank to start, and when the engine has started and is running. If you turn the key and the fuel pump starts, you have wiring issues. There is no 'prime' operation for the fuel pump.
There are some discussions here about the COR and its operation.

Kiroshu

Check your ignitor and wires from your ignitor as well.

glennjg61

I will try these tomorrow. Is there a reset for the cor? Sorry if my questions sound like I don`t know what I`m doing but I`m learning as I go. I`m old school - carb not efi is all I`ve had to work on in the past and there was no computers HA

Kiroshu

You really don't reset a relay... its either on or off.... take it out and check it for ohms.... clean the contacts inside it....

abecedarian

The COR should "self-reset": when power is removed by turning the ignition switch to off, it opens and breaks the circuit to the fuel pump. And it should not turn back on until you actually crank the engine to start and the engine starts running.

You can test the COR by checking the FP terminal in the check connector for voltage during the above mentioned situations.
...
or...
turn the key on- no voltage at the FP terminal
turn the key to start, engine cranks- voltage at the FP terminal
engine runs- voltage at the FP terminal
engine not running- no voltage at the FP terminal

glennjg61

I cant wait to try everything you guys are telling me. I really appereciate your help

glennjg61

Well I tried everything you guys said to try even starting fluid in vacuum line at throttle body and nothing. This is so frustrating!!! Any other ideas???

Kiroshu

Sure it would not kick over at all with starting fluid? If not then you need to look at your spark....

glennjg61

No it just keeps acting like it wants to start but wont. It`s got good spark. I put in new plugs, cap, rotor and distributer

glennjg61

Well I got it running on Tuesday the 17th. I kept moving the distributer while my girlfriend was cranking it over and it finaly started. I timed it to 0 BTC and took it for a drive. It ran good except if I let the RPMs go too high before I shifted gears it would sputter a little bit. The next day it wouldnt start even after moving the dist.

I figured it must be the timing belt so I bought one to put in. I tore it apart today and the timing is right on and it looks like the belt has been changed recently so I put it back together and it will only crank over and nothing else.

I`m totaly stumped! Does any one have any ideas?