This is my first post but I have searched and messed with this truck for the past 3 weeks. 1993 toyota 22re 4x4 truck that is stock with 238,000 miles. Owned the past 15 years and given me no trouble at all. I have read every thread I can find online but can't figure this one out. Lots of similar threads but I don't want to just throw a bunch of new parts on the truck just guessing. Here is what it is doing.

Truck ran fine one week and next weekend it wont stay running. Turn the ignition and truck fires and runs fine for maybe 2 seconds and then dies almost immediately. It will occasionally sputter a few hits like one or two cylinders are trying at a really low rpm before it dies but its pretty abrupt. It will start up, run a few seconds and then die everytime you turn the key. If I touch the throttle any time at all it dies instantly. I believe it is only running with the cold start injector and dies once it gets the signal to shut off. Does the CSI get shut off instantly if you give it any throttle?

Here is what I have tried to troubleshoot. First thing I checked was the fuel pump cor. It all seems good. Turn key on and push flap above air filter and you hear it kick on. Just for kicks I did jumper fp and b+ to keep pump running and it still starts and dies. I next tried starting fluid in the intake and the truck would run as long as i sprayed the correct amount. I could turn the throttle blade open when spraying and the truck would rev and sounded fine. I am assuming this means timing and ignition are probably not my issues. So I am leaning toward a fuel issue at this point.

Next step was changing the fuel filter and testing the injectors with a noid light. Noid light seemed to look good on injectors #2 & #3. Didn't test #1 & #4 because they are more difficult to get to. The pulses were very rapid when initial cranking and then slowed slightly once the engine started. It looked to me that they continued flashing and only stopped when the engine stalled.

Next test was fuel pressure at the cold start injector fitting. Numbers were mid 40's with the fuel pump jumpered and dropped to upper 30's as the truck started. Someone suggested those numbers were low so I put a toyota fuel pump and strainer in the tank which did not help at all. Doing more research I believe around 39 psi is normal once the engine vacuum causes the pressure regulator to drop the pressure. I did plug the vacuum hose going to the fpr and it did not make any difference. I also did not find any fuel in the vacuum hose so I think everything is good there.

At this point I started testing any component I thought might be an issue or items that people were suggesting might be causing the problem just to be thorough. Using a multimeter the afm in the air box, the throttle position sensor and the engine temp coolant sensor tested good. I also cleaned the idle air control valve while I had it out. I tried unplugging the tps and it did not change anything other than the engine might have idled slightly higher before it died. Unplugging the cold start injector the engine would not fire at all. I have also pulled the plugs and they look fine. All the vacuum lines look connected and in good shape. I did spray starting fluid around all the hoses while the truck was running and could not find any places that caused the engine to idle up so no obvious vacuum leaks.

One thread with the same symptoms ended up being a missing ground on the intake. I checked and my ground is in place on the intake. I checked all the other grounds in the engine bay and the ground strap to the back of the head was broken. I repaired it but it made no change. Several other threads have led in the direction of corroded wiring leading to the injectors. I have not dug into the wiring yet because the noid lights seemed to show pulses on the two injectors I checked. I might try to check #1 & #4 injectors with the noid light again to make sure they are flashing but I have read that the injectors are all tied together and they all fire in unison. If the issue was bad wiring or bad ground I would think the noid lights would not flash at all. There was also a comment that if the igniter was not sending the IGF signal to the computer it would shut down the injectors and throw a code. I do not have any CEL codes so I am hoping that is not the issue because I do not think I could test if the IGF signal is being sent. One other thread with these symptoms was fixed by replacing the ECU. I pulled the cover off the ECU to check for any obvious burned spots and it looked spotless inside.

Everything I have checked is making me think the injectors are getting a signal to fire but for some reason some or all of the injectors are not actually spraying fuel. I can't hear any clicking in the injectors using a stethoscope when it is running. I considered a stuck injector causing an overly rich condition but since it runs fine on starting fluid leads me to believe it is not a rich condition. Does anyone know of a simple way to determine if the injectors are actually spraying? I tried disconnecting the CSI, unhooking the coil and turning the engine over a few seconds to see if the plugs get overly wet but they still look the same and I don't smell fuel. Any thing anyone else can think of before I pull the fuel rail and the injectors? If the fuel rail and injectors looks clean at that point I have no idea what the next step would be. Would hate to send off the injectors and go through the hassle and expense of having them rebuilt if it wont help the problem. Any help or advice would be greatly appreciated!

 

Your symptom points directly to the Air Flow Meter (AFM)

Any chance the plug is not secure on your AFM? Under no circumstance should you remove the 2 screws that secure the plug socket into the AFM!

Here is how to test the AFM:

http://www.4crawler.com/4x4/CheapTri...tml#AFMtesting

 

Thanks for reading Paul. The plug doesn’t seem to click into place as securely as my other connectors but I think it’s making contact. I went through the test of the afm as listed and it seems to test ok. Do you happen to know what else the afm controls? I know it signals for the fuel pump and it does cut on when I push the flap. Does the Ecu use the amount that the flap opens to help control the injector pulses?

thanks

 

Have you checked for any engine codes?

 

I rechecked the afm based on on 4crawler Page and all numbers were in spec. The last time I checked there were no codes when I jumped the diagnostic port. I might rent out the noid lights and fuel pressure gauge again to double check there. Just want to verify that the noid lights stop flashing after the engine starts to die and not before.

 

Checked for air leaks in your intake tube, especially the bellows?

I remember one other member had the same issue and it ended up being a broken wire from the igniter to the ECU, but I think he got an engine code that steered him that way.

Yes, testing the fuel pressure is a good next step.

 

I did inspect all the vacuum hoses and intake tube pretty good but will keep looking them over. I had my dad start it and I sprayed all around the hoses while it ran and didn’t come across any areas that increased the idle. Hopefully it isn’t a broken wire since the noid lights do flash. Thanks for giving me suggestions.

 

How cold is it outside? Does it ever run after numerous start attempts? Basically, there's enough heat built up within the engine? If that's the case, it could be your IACV....

 

It is still in the 60’s here for temp. I am curious if it will run longer on the csi once we get a cold snap. I have started it numerous times in a row and even ran it on starting fluid up to a minute or so hoping it would help but it continues to only run for a second or two.

I did recheck fuel pressure last night and have around 42 psi with the pump running and it goes down to about 37-38 once the engine pulls vacuum on the regulator. Still trying to get the noid lights connected to injectors #1 & #4.
Thanks for the recommendations so far!

 

Dont rule out fuel pump just yet. I was working on a 1999 Corolla doing the EXACT same thing. Fired for a couple seconds then dies. everytime. Ended up being the fuel pump o ring where the electric motor goes into the fuel pump housing. it had deteriorated after so long and the FP was still making some pressure just not enough to keep engine running longer than those 2 or 3 seconds. Wild card but its worth pulling housing out and giving it a gander.

 

I believe the fuel pump and pressure are good. It has a brand new Toyota pump, strainer and fuel filter. I had the same fuel pressure before and after the fuel pump replacement also.

 

You said you can hear the FP running when jumping fp & b+, but engine still dies. Have you tried to do that with the AFM unplugged to see if the engine still dies?

 

Paul I don’t think I have tried that combination yet. I will jump the fuel pump and see what it does with the afm unhooked on my lunch break and see what it does. Thanks again!

 

Unplugging the afm connector and jumping the fuel pump gives the same start for and stall. Does that mean anything that it acts the same with the afm unhooked? I also managed to get injector #1 unhooked and the noid light appears to flash correctly. #4 injector is the only one that I have not been able to reach to verify it is getting pulses.

 

IGf, IGt signals reaching ECU? No ignition no injector pulses.

 

If the noid lights are flashing does that mean the signals are going to Ecu? I have read igf signal failure will cause the Ecu to stop the injector pulses once it is recognized. I thought that might be the issue but the pulses don’t just stop. They slow as the engine rpm drops when it dies. Makes me think the injector pulses are good.

I guess my next step is to tear down the fuel rail and injectors and hope I find a fuel blockage or something obvious.

 

might be time to try another ECM and see if theres a difference

 

This is a perplexing one. You're getting pulses at the injectors, fuel pressure is good, engine runs fine when you spray starting fluid in the intake.

But you did say you aren't hearing the injectors click. Have you tested the resistance of each injector?

 

fuel pressure seems to be a possible target, or at least delivery issue.

 

The injectors on a 22re are pretty much audible with out a stethoscope. It's the signature sound of the 22re "sewing machine" 50/50 flat tappet cam and injector slam.

You might end up pulling the upper intake and finding the injectors are fine (not sticking) and it's the driver circuit has failed or there is a bad ECU ground (E1 to bat-). Do a voltage drop test between batter negative post and E1 on the ECU plug. (Red lead back probe E1 at ECU, black lead to battery negative post.)

Another simple check is putting jumpers on the #1 injector and strobing it to power/ground, should have a healthy click out of it. You can make this a little safer by using a little 9v cell since the only put out about 50ma If you're quick the vehicle battery doesn't pose a lot of danger of breaking things, but you could arc weld the wire to the battery then it's bad.. Where a 9v and carb cleaner is a recognized method for diy injector cleaning.