91 4 Runner Help

I Have a 91 4 Runner V6 5spd- It Ran good when I bought it 5 months ago- about a month ago it it wouldn`t start unless I held the trottle down. After a few days of this it wouldn`t start and if it did it would bearly run for a few seconds with or whithout the throttle pressed down. I put in a new fuel pump,filter, cap, rotor and plugs-still nothing. Took it to a shop to have them diagnose the problem. They couldnt get any spark and told me it was the distributer or computer. I put in a used dist.-nothing. put in a used computer- nothing. Put in a used igniter and coil today and had a plug out to see if it had spark. My girlfriend was cranking it over and it had spark so I told her to stop and put the plug back in and had her crank it over - no spark!!! Does any one have any ideas??? I`m going nuts and broke trying to get it running:banghead:

How did you determine that you had no spark when the plugs were installed?

Because when the plug was out when I was checking for spark it fired up and I told her to shut it off and replaced the plug and had her crank it again and all it would do is crank over so I checked for spark and there was none. Thats got me baffled as to why there was spark for a few seconds then nothing???

Have you checked for codes in the ECM?

Yes . When I took it to the mechanic they checked and there was none. The check engine light has never came on either (it does work). As I said before I`ve also changed the ECU.

Test the fuel pressure and volume at the fuel rail. See if holds pressure after the key is shut off.

How would that affect the spark?

Insufficient fuel pressure may cause the ECU to keep the engine from getting a spark signal. Suddently getting spark and then not doesn't sound like an electrical problem. Sounds more like a problem with regulation. May possibly be a bad sensor of some type. Lack of ECU codes is a problem.

Well I went to test the fuel pressure and realized the fuel pump wasn`t running. Checked all of the fuses and they were good. So I dropped the tank to see if there was power at the pump and there was none. So I hooked the pump up directly to the battery and it works fine (it is brand new). As the fuel pump was running it was just flowing through the fuel pressure regulator so I pulled the gas line off of the regulator and put a fuel pressure gage on it and left it overnight and it held pressure. Why wouldn`t I have power to the pump? spark plugs? and does this mean the pressure regulator is bad or is it just because there is no vacuum to contol the regulator. p.s. the pump worked fine when I put it in a few weeks ago.

To check the fuel pressure, you need to connect (paper clip or wire) terminals FP and +B on the DLC1 connector (near the No. 2 relay block under the hood) with the ignition ON. Pinching the fuel return hose with your fingers should give 57 psi.

There is a fuel pump switch in the VAF meter. Check to make sure it is working properly. The shorting between FP-B+ bypasses the fuel pump switch. The contacts for the fuel pump switch are FC and E1 on the VAF meter.

There is a troubleshooting procedure starting on page EG2-202 of the 1993 pick-up manual stickied at the top of this forum - the link is labled Fuel Pump below.

See these links:

Description (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/81descript.pdf)

Operation (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/82operatio.pdf)

Preparation (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/83preparat.pdf)

Precautions (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/84precauti.pdf)

Diagnostics (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/85diagnosi.pdf)

Troubleshooting (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/86troubles.pdf)

Fuel Pump (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/87fuelpump.pdf)

Coldstart Injector (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/88coldstar.pdf)

Fuel Pressure Regulator (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/89fuelpres.pdf)

Injector (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/90injector.pdf)

Fuel Tank (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/91fueltank.pdf)

Volume Air Flow Meter (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/92volumeai.pdf)

Throttle Body (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/93throttle.pdf)

Electronic Parts Location (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/94electron.pdf)

EFI Main Relay (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/95efimainr.pdf)

Circuit Opening Relay (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/96circuito.pdf)

Cold Start Injector Time Switch (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/97colds.pdf)

Engine Coolant Temperature Sensor (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/98engineco.pdf)

Fuel Pressure Control System (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/99fuelp.pdf)

EGR Gas Temperature Sensor (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/100egrgaste.pdf)

Heated Oxygen Sensor (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/101heatedox.pdf)

ECM (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/102engin.pdf)

Fuel Cut RPM (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/103fuelcutr.pdf)

Service Specifications (http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/104services.pdf)

WOW!! Lots of information! Thank you! It`s alot better than the Haynes repair manual that I`ve been working with. I`ll check all of these and let you know what I find. THANKS!!!!

Download the '93 Pick-Up manual at the top of this forum for more information.

I keep looking for the `93 pick-up manual at the top of forum but I cant find it. I wouldn`t mind having it to download for a reference.

Well it`s been about 2 weeks since I`ve been on here. I found out why I didn`t have any spark-it ended up being the VAF meter was bad and I finaly tracked one down today after checking several junkyards (I was suprised to find them so hard to get because every where I went they were already sold) anyway I put it in and there is good spark and when I try to start it, it acts like it wants to start but wont. Any ideas??

Go through the troubleshooting procedure again. There are a lot of possible problems that you need to check.

Yea I was going to try that again and see if I can find something else. I`ll let you know if and what I find. The waether is supposed to turn nasty and unfortunaly I`m not the proud owner of a garage to work in.

Plug wires? Fuel pressure? Must be 45 to 50lbs. Keep up with the good information in your posts and we'll get you running again. Let us know

The plug wires are good and I`ve checked fuel pressure and that is good. I finally got it started on tues. the 17th by having my girlfriend keep cranking it over while I moved the distributer. After it started I took it for a drive to warm it up so that I could time it. When I put it at 0BTC it wouldn`t run that good so I advanced the timing and it would start up and run fine for the rest of the evening (except that you had to keep the throttle open all the way to start it and it would kinda sputter a little bit if I rapped it out before I shifted gears). The next mornig no start moved the distributer around again that evening still wouldn`t start. I decided that I must have somehow missed that it was jumping the timing and that was where my problems were. I bought a new timing belt and tore it apart thinking the belt was probably bad and it looked like it had been changed recently and the timing was right on perfect. I put it back together and it wouldn`t start unless I moved the distributer. When I got it running and timed it, it would only run good when the timing was advanced (This time it was way off of the scale to run). Now I`m totally stumped!! I`ve had people tell me that it is the distributer but I`ve got 2 of them and tried them both with the same results