I have a 95 4runner with 186,000 miles on the 3vze engine. I replaced the timing belt, valve cover gaskets, and front wheel bearings & brakes. I have it all buttoned back up, with all of the hardware in the right spots and all of the hoses connected to something. IT has spark and fuel to the fuel rails. I left the throttle body connected to the plenum. There are no codes stored in the ECM. What should I check next to try and figure out why it won't start? It seems to crank as well as it did before I took it apart. Thanks

 

Also, the A/T Oil Temp light is now on when attempting to start the engine and I dont remember if it came on before I started the timing belt replacement or not. It seems out of place for it to be on so probably was not coming on before the "repair"

 

Sure the distributor is in properly? Getting voltage to the injectors?

 

Don't know about the injectors. How can I test that without pulling the plenum? Or is there room? There is pressurized fuel getting to the fuel rail.

I didn't pull the distributor and when I line the crank up to TDC the rotor is pointing straight up to where the #1 plug wire connects.

 

I'll go pull a plug and see if it has fuel on it... I also put in new plugs. Forgot to mention that earlier.

 

Not too familiar with the layout on the v6 but I believe you'd have to pull the upper manifold to get to the injectors. Maybe someone a little more familiar will chime in.

 

I pulled the #4 and #5 plug and they were both dry. So I guess my claims of having fuel to the cylinders was premature.

What should I check next?

 

I'd go through and thoroughly check all the fuses, connectors, etc. everything you touched... all the intake duct, etc. If all that's fine, you can try to manually activate the fuel pump by putting a jumper in the diagnostic plug Fp and B+ terminals, then cranking the engine. If it starts then we need to figure out why the pump's not working.

 

No the pump works. I did the Fp and B+ jumper test before I started the thread. The fuel rail has pressurized fuel. I now think the injectors are not opening. I will go through the fuses and connectors. What voltage should the injectors have coming to them?

Thanks for your help so far

 

Is the short vacuum hose connected to the fuel pressure regulator at top front of engine? All vacuum hoses connected? May want to shoot some WD-40 down a vacuum hose to see if the engine will start. I am assuming the cam timing is correct and electricals are getting fire. Check all your electrical connectors....may have pulled one apart during the belt change?

My $0.02

 

IIRC, both terminals on the injectors should have 12v. If you don't have that on both terminals, somethings wrong with the wiring. One terminal is switched to ground by the ECU to fire the injectors. If you can get to one injector plug, that should be sufficient to test since they are all wired in parallel.

 

SEAIRESCUE: The little hose it connected and I re-checked the vaccum lines. The cam timing was set as per the FSM and the distributor is distributing spark as I checked at more than one plug (#5&#4). I hope the belt didn't skip a tooth while I was messing with tensioning it. It didn't feel like it and when I did turn the crank 2 revolutions the timing marks on the cam pulleys lined up like when I had set the belt.

abecedarian: The #2 Injector had +12V at both terminals with the ignition on.

Any other suggestions for things to check? Is there a diagram to follow for the larger diameter hoses that connect to the plenum? I'd like to double check those but haven't found a reference. I guess at this point I should just start going through the Troubleshooting w Volt Ohmmeter procedure. Thanks for your prompt replies.

 

If you've got 12v on both terminals, the injectors are connected to the ECU.
Are all the connectors around the igniter / coil firmly connected, well seated, not wet or corroded?
Have you tried loosening the fuel line to the cold start injector and verifying there actually is fuel in the rail?
Do you have a 'noid' light? It plugs in, in place of an injector, and when you crank the engine it flashes.

 

Check the distrib connector to make sure none of the pins are pushed back.

You can use a mechanic's stethoscope to listen to an injector while someone cranks it. If it's firing, the clicks will be loud and clear.

If the injector isn't firing, there are some ideas in this post:
https://www.yotatech.com/forums/f116.../#post51130411

It's rare to get spark but no injector pulses. Usually that means a bad connection in IGF between the igniter & ecu, or a bad E2 or E01/E02 ground. Even with a bad IGF, there should be at least one injector pulse at the very beginning of cranking.

To back-probe terminals on the ecu, you can poke needles into the connector and press the test leads against them, if you don't have back-probe adapters for your leads. While you're at the ecu, verify the E2, E01, E02 and E1 grounds all have continuity to the neg batt post when ignition is on. You can use a jumper cable to extend the neg post into the cab for testing.

 

abecedarian: The cold start injector has fuel spraying out of it when I loosen the bolt through the fuel line at the CS injector. I do not have a noid light.

sb5walker: With the ignition on the E01 E02 E1 E2 and E21 are all disconnected from the negative post on the battery. When the ignition is off they are all connected to the battery. The #10 and #20 pins have +12 V and the IGF pin shows +0.5V when the ignition is on.

Why do the ground pins on the ECU become disconnected when the ignition is on? Where should I look to begin to repair that? I hope its one spot rather than 5. I did unbolt the ECM from the body of the car to test the pins. Would that cause the grounding issue? Thanks for your help. I'm glad to at least get some more things sorted out that it is not.

Paul

 

Also, the connectors at the distributor and igniter all look fine and seem seated properly.

 

You sure you're not just having us all on? That's bizarre. E01 & E02 are the fuel injector grounds, my 89 fsm shows them connected to the engine block, but I haven't verified that. On my 89, there's a ground wire bolted to the back of the plenum, too. I think I remember a ground strap on the back of one of the heads, but I forget. E1 is supposed to be a chassis ground, connected to the drivers side pillar. I haven't tracked that one down either. (You SURE E1 didn't have continuity to ground??)

E2, the ground for most of the efi sensors, is called an engine ground, but it doesn't have a direct connect to the engine - it grounds internally through the ecu, probably to E01/E02. I could see E2 getting messed up due to a bad ecu, but the others are supposed to have solid direct connections to either the engine or chassis.

That's my best read on the wiring, but I'm not a professional tech - just a shade tree w/some years of experience. Maybe one of the more experienced techs around here will have better information for you. The fact that the grounds apparently lose continuity with ignition on seems very strange. Could one of the ground straps be misconnected?

I would first verify that there is continuity (with ignition on and off) between the engine block/heads/plenum and neg batt post, and a clean spot on the chassis and the neg batt post. If something doesn't have a good ground, then you know where to look. Otherwise, look around for a loose ground strap, or, trace the E01/E02 and E1 grounds.

Good luck, and keep us posted.

 

Not so sure I'd bet the soul of my first child on it, but pretty sure. I'll double check the ECM grounds and those you recommend after work and report back here. Thanks again

 

Not sure; you might connect it temporarily to make sure that's not causing a problem.

Stupid question: you DO have the VAFM connected & wired, RIGHT?!?

 

Hi TNRabbit,

Yes the VAFM and entire airbox is wired and plumbed up. I did not take it out during the timing belt swap. I did take out the big rubber hoses and elbow but they are back in. I have not checked the sensor, or the TPS for that matter.


Thanks and I'll run a ground to the ECM case when I get back to the car to test the other grounds.