Solid Crank, Zero Start - Ideas?

[ShakenBake]

Looking for ideas troubleshooting what's ailing my war wagon. I have a supercharged, 5 speed, 1997 4Runner with ~235k on the clock. I've owned it for almost 13 years and it's easily the most reliable car I've owned.

About 3 weeks ago, I drove to the grocery store. The 4Runner had no CEL and nothing felt off when driving it there. Finished shopping and went to start it and it would crank and crank but would not start. To make sure it wasn't a dead battery (replaced 8/24) I tried using a portable jump starter. It didn't change anything. I left the car in the parking lot overnight and tried it again the next day. Started right up and drove home. No CEL. I drove it to work the next morning and home again in the afternoon. Again, no CEL and nothing felt off when driving. I go to start it the next morning and it would crank and crank but not start. It's been in the garage since then.

I noticed the tach barely moved while cranking the first time this issue appeared and the second time the tach wouldn't move at all. Based on that, I convinced myself that the crankshaft position sensor was bad so I replaced it but it did not solve the problem. The car would crank and crank but not fire.

I took another look under the hood checking for a loose ground or anything that would explain why it's still not starting. I noticed pink and yellow fiberglass insulation stuffed btwn the supercharger and the engine block. Now I was convinced that whatever foul rodent that made this nest must have chewed a wire. I removed the supercharger and cleaned out the nest. However, upon closer examination, I could not find anything chewed, damaged, or disconnected.

I finally have all the gaskets to put it back together but I'm still not sure what's causing this issue and I don't want to waste time and effort putting the supercharger back on if I have to remove it again to properly troubleshoot.

FWIW, I replaced the plugs, wires, and ignition coils Summer '24. Fuel filter and fuel pump replaced around 4 years ago. Dash clock that stopped working seemed to work again when attempting to start it.

Thoughts as to what is causing this and how to diagnose? What should I be checking before bolting the supercharger back on? Can I check the camshaft position sensor without removing the tension pulley installed with the supercharger?

 

[Ac3_21]

had the same issue with my '02. wouldn't want to start back up after 1 or 2 stops once warm. just like your situation, no other issues. from my research on this issue it could be coolant temp sensor in the front of valley (goes to ECU not gauge) or also fuel pump wiring. my issue ended up being the power supply harness to the fuel pump, power and ground wires between top cover and the fuel pump. wires were very corroded which I'm assuming raised resistance once hot and would not get voltage to pump. hope this helps.

 

[2TH4IST]

Sounds like a fuel pump. If it was a issue with a sensor it would throw a code. When the fuel pump is cool it will work, once it gets hot it locks up. Do you remember what fuel pump you are using? Walbro or other aftermarket don't last that long from my experiences.

 

[ShakenBake]

Thanks for the replies! I am running a Deatschwerks 225 fuel pump. That was installed around 2020, just before I installed the supercharger. Fuel filter was also changed at this time.

Since I have the supercharger removed, I will probably just replace the engine coolant temp sensor at the front of the engine. That is where I found the rodent nest and maybe the fiberglass insulation trapped enough heat and cooked the sensor.

In parallel, I'll take a closer look at the fuel pump wiring, connections, etc.

 

[2TH4IST]

Sounds like a plan. Make sure you get a good known sensor. I've had very bad luck with those sensors if they are aftermarket.

I'd pop off the fuel pump access cover and jump the fuel pump. One to check it works, then let it run for a while, disconnect power and jump it again to see if it turns on again. Try to let it run the same time as when it happened. See if it's the pump locking up when warmed up. While that's going on you can check the wiring/fuses/relays and change out the temp sensor.

 

[vegask]

Sounds like the EFI relay. One quick way to test is to swap the EFI relay with the Tail relay (in the under hood fusebox).

 

[T4R2014]

I'm suspicious of the aftermarket pump.

 

[vegask]

I'm suspicious of the aftermarket pump.

Always a possibility. They can disconnect the return line and crank away and see if any fuel comes out. Fuel pump only runs when you are cranking/running.

The fact that he said there was no tach activity means the igniters are not getting power. And no CEL with the key on means the ECM is not getting power. Both of those feed off of the EFI Relay under the hood.

I only know this cause I broke my EFI relay a few months ago, 28 year old relays do not like to be bumped around.

 

[ShakenBake]

Sounds like a plan. Make sure you get a good known sensor. I've had very bad luck with those sensors if they are aftermarket.

I'd pop off the fuel pump access cover and jump the fuel pump. One to check it works, then let it run for a while, disconnect power and jump it again to see if it turns on again. Try to let it run the same time as when it happened. See if it's the pump locking up when warmed up. While that's going on you can check the wiring/fuses/relays and change out the temp sensor.

I ordered the OEM engine coolant temp sender, washer, and wires from my local Toyota dealer. I normally don't go through dealerships but this gives me the best chance to get every thing before the weekend.

I like your fuel pump idea and I'll have to see what I have lying around to jump the pump. I just moved and all my random wires and clips are still 2400 miles away (driving).

I checked all of the fuses but not the relays. Oddly, the "POWER" 30 amp fuse in the dash was corroded so I'm replacing that.

 

[ShakenBake]

Sounds like the EFI relay. One quick way to test is to swap the EFI relay with the Tail relay (in the under hood fusebox).

Once I replace the engine coolant temp sender and get the supercharger reinstalled, I will swap replays and see if that changes anything, assuming the sender doesn't do the trick.

 

[ShakenBake]

I'm suspicious of the aftermarket pump.

This is definitely on my radar as well and the fuel pump will be my next major rabbit hole if the engine coolant temp sender and/or relay do not fix it.

Also, I noticed you're in located in Reno. I just moved from PA to South Lake Tahoe, CA so you've just been promoted to my local 4Runner liaison. Congrats!

 

[ShakenBake]

This is definitely on my radar as well and the fuel pump will be my next major rabbit hole if the engine coolant temp sender and/or relay do not fix it.

Also, I noticed you're in located in Reno. I just moved from PA to South Lake Tahoe, CA so you've just been promoted to my local 4Runner liaison. Congrats!

This comment was intended for Vegask

Also, I noticed you're in located in Reno. I just moved from PA to South Lake Tahoe, CA so you've just been promoted to my local 4Runner liaison. Congrats!

 

[vegask]

This comment was intended for Vegask

Also, I noticed you're in located in Reno. I just moved from PA to South Lake Tahoe, CA so you've just been promoted to my local 4Runner liaison. Congrats!

Well, I grew up in PA. So we are friends now.

 

[calimobber]

Might be worth and easy test. Im dealing with similar ish issue but mine normally starts after long crank.

One time after driving 2hrs I got gas and went to leave it didn't start. I cranked and cranked. used starting fluid and it started then ran fine. Can try that to see if once it runs it stays running or anything changes or it just dies again.

Also my scan gauge reads the etc sensor so im sure a phone ob2 scanner app can show you that too. I unplugged my etc temp sensor to be sure and the scan gauge changed from 190F to -40. tried starting with it unplugged and nothing changed still long crank start.

 

[ShakenBake]

I replaced the ECT sender, reinstalled the supercharger, and swapped the EFI and Tail relays to no avail. It's still not starting.

Based on the replies, now I am troubleshooting the fuel pump. When the key is turned to accessory mode, I'm pretty sure I can hear the fuel pump priming. I don't think I have what I need to jump the pump so I may see if starter fluid gets it to fire and/or disconnect the downstream end of the fuel filter and see if priming the pump makes a little mess.

 

[vegask]

I replaced the ECT sender, reinstalled the supercharger, and swapped the EFI and Tail relays to no avail. It's still not starting.

Based on the replies, now I am troubleshooting the fuel pump. When the key is turned to accessory mode, I'm pretty sure I can hear the fuel pump priming. I don't think I have what I need to jump the pump so I may see if starter fluid gets it to fire and/or disconnect the downstream end of the fuel filter and see if priming the pump makes a little mess.

The fuel pumps in our trucks do not prime, they only run when the motor is cranking. Disconnecting the return line is probably the easiest way to see if fuel is getting pumped in. Or you can get to the pumps harness under the rear seat and put a test light on it.

More import question, do you have a code reader and does it actually communicate with the ECM when the key is on?

 

[ShakenBake]

Update. I tried starting fluid (sprayed right into intake tube, before TB) and while it didn't get the engine running it sounded different than previous attempts. It sounded like the engine was just about to start but, as soon as the starting fluid was burned off, it would struggle and die. This reinforced the theory that lack of fuel is my issue.

Chasing this thread, I disconnected the fuel line upstream of the fuel filter and turned the key to accessory and I didn't observe fuel coming out of the fuel line. Next, I tried starting it to see if that made fuel flow. I got a spurt of fuel, then nothing. It almost sounded like there was a blockage that cleared so I tried to start it again, and no more fuel was observed flowing from the disconnected fuel line. Tried again in accessory mode and nothing. I can hear the fuel pump turn on in accessory mode but no fuel flows. Maybe the ECU is somehow aware the fuel line was disconnected and compensated accordingly.

Based on this, my guess is the fuel pump is clogged or crapped the bed. Since I'm pretty sure I can hear it priming, I'd assume it has power. So if it's not a power issue to the pump, safe to assume it's crapped the bed and start ordering parts to replace the fuel pump? If so, is anyone aware of a slightly higher flowing fuel pump that's more reliable than Deatschwerks?

 

[ShakenBake]

The fuel pumps in our trucks do not prime, they only run when the motor is cranking. Disconnecting the return line is probably the easiest way to see if fuel is getting pumped in. Or you can get to the pumps harness under the rear seat and put a test light on it.

More import question, do you have a code reader and does it actually communicate with the ECM when the key is on?

I do have a code reader. What should I be looking for?

 

[vegask]

I do have a code reader. What should I be looking for?

Just see if it will connect and read codes, this will at least tell us if the ECU is getting power. Then double check for any codes.

 

[2TH4IST]

The 4runner don't prime the fuel pump with the key in acc. It only runs the pump while cranking. I'd now jump the pump connector to see if you can get the pump to work.