Crank no start after clearing codes

Hi yall. New here, and I'm having an issue with my Tundra.
I had a CEL, codes 171, 172, 174, 175, 441, and 446. The 441 and 446 have been present since I bought the truck about a year ago, so I don't think they're related.

The 17* codes showed up a few days ago, and I noticed the truck was low on power. I decided to start by cleaning the MAF. After doing so, I cleared the codes, and now it cranks but no start.
I ruled out ignition by grounding a plug, so then I turned my attention to fuel. I sprayed some starting fluid, and it seemed to make a difference. I didn't use a lot, so it didn't start, but I could tell the difference. I checked all fuses. I tried listening for the fuel pump, but I couldn't be sure because it was hard to hear while the starter was cranking (I know it only "primes" while cranking).

Is there any way to make the fuel pump come on without cranking? I'm at work so I can't try it now, but I saw a video showing how to bypass the relay, and power the pump straight from the battery. Will that make the pump work without the key being on the crank position?

Also, any ideas what could've cause this based on what I did (clean MAF, clear codes)? I did try another MAF, and didn't make a difference. I also replaced the crank position sensor because I had a new Hitachi one already.

 

The EVAP codes (P044x) are indicative of your fuel filler neck beign cracked, bad gas cap, cracked evap canister, cracked EVAP vacuum line, or similar. Smoke test will suss out the source. There was a TSB on the '03-'04 trucks for a faulty fuel filler neck and earlier years have found theirs cracked up. Can link a thread to the last case if you need.

The array of P017x codes is indicative of a couple of things. Either the ECU is getting bad air volume information (from the MAF), or you have blown out the intake gaskets on both banks. I mean, there's a slew of other stuff it could be, but ultimately those codes are telling you your air/fuel ratio is too much air and not enough fuel. The fact they popped up IMMEDIATELY after you cleaned the MAF is obviously steering my thought process on this. Specifically...

• HOW did you clean the MAF?
  • With what specific chemical (you must use MAF cleaner specifically)?
  • Did you throw it back in and fire the truck up immediately, or let it properly return to room temp?
  • Did you not fully seat its connector afterward, have you checked the connector for bent pins?
  • Did you notice any physical debris on the sensor inside?
  • Did you properly remove the negative battery cable for at least 10 minutes while cleaning, to force the ECU into re-learn mode, as you always should when cleaning the MAF, the TB, or changing coils/plugs/injectors?
• Is the MAF the original Toyota (i.e. Hitachi) brand MAF? Or has it been replaced at some point?

These trucks are pretty sensitive when it comes to electronic components related to monitoring/ignition/fuel delivery/emissions. If you need to replace the MAF, only buy Hitachi brand (or get it from Toyota, in a Toyota box, with the Hitachi part inside, and pay 50%-100% more). This is not a part you want to buy aftermarket. And if you replace the MAF, take the negative battery cable off for 10 minutes to force re-learn.

 

PS -

You'll want to check the red wire on the MAF connector for 12v, if no voltage, check EFI fuses, in the fusebox next to the battery.

Here's how to test the MAF (assuming it's getting power), to see if it's sending stupid readings (reply #21). Note the readings will be higher or lower depending on outside ambient temp. You may want to read the whole thread in general, just note some things (like fuse location) differ by year/cab type.

https://www.tundras.com/threads/p01...requires-ecm-replacement.119182/#post-3063645​

And this is courtesy of @KNABORES which may at least help you understand what P017* can be caused by. But because you're throwing codes showing lean on BOTH BANKS, the issue won't be O2 sensors, both won't go bad at once.

https://www.youtube.com/watch?v=AzG388iE5w4​

 

Thanks for all the info!
Just to clarify, I got the 17* codes before I cleaned the MAF (it's why I cleaned it). After cleaning it with MAF cleaner (CRC I believe), I waited until it fully evaporated before putting it back in (maybe 5 minutes), and then it would crank, no start.

Both MAFs that I tried are Hitachi.

All fuses were good.

I removed the negative cable for almost an hour.

The 44* codes have been present since I bought the truck, so I don't think they're related. The truck was so neglected by the previous owner that I had a lot of other things to take care of.

I'll check the voltage when I get home. For what ita worth, I had just driven the truck prior to cleaning the MAF/clearing the codes.

 

Only giving EVAP code info for reference.

But ... Occam's razor. If the truck was running, you turned it off, cleaned the MAF, reinstalled the MAF and it's not running, the issue probably something you did with the MAF. I'd focus on that for the moment until you can verify it's not.

If you're telling me you have two MAFs, and it's doing the same thing with both MAFs, then I think you need to be inspecting the wiring connector for the MAF very carefully for bent pins, because that's the only logical thing that could've went sideways, other than something stupid, like, you unplugged the MAF with the battery still connected, and a spark blew a fuse. But that could quickly be debunked by testing the (I believe red) wire at the MAF connector for 12v+.

But humor me for a second because, as I mentioned, P017x codes are indicative of too much air and/or little fuel. This is before we had the info "I have two MAFs and tried them both, same response". And you mentioned the truck running like shit prior. The other possibility here is your fuel pump is not pumping fuel, and it was on the way out and/or a wire that runs to the pump is fucked (mice sometimes love nesting on the tank and will chew wires up).

There's an easy way to tell if your problem is fuel delivery. Go to the store and get a can of starter fluid (ether) if you don't have one. Spray a 1-2 second shot directly in the throttle body with the butterfly open. Put the intake tube back on. Start the truck. If it fires, you have a fuel delivery issue and that's where you need to be focusing your diagnostics. In which case, if you recently changed your timing belt (last 10-20k miles), I'd probably be checking to see if someone stupidly misrouted the crank position sensor harness, and it got nicked by the belt. Happens, too often.

 

Assuming it's a fuel issue, is there a way to get the pump to run without cranking? If I bypass the fuel pump relay direct to battery will I still need to crank to make the pump run, or will it run with the key on the "on" position? I just can't hear the pump because of the noise while cranking.

I won't really have a chance to get under the truck until this weekend, so I'm looking for any diag I can do from the top (like checking voltage at the MAF, starting fluid, etc).

 

Again, I reapeat: If you want to IMMEDIATELY know if it's a fuel delivery issue, get a can of starter fluid and follow the direction above. It's the single fastest way to 100% determine if you have a fuel delivery issue.

Otherwise, you need to review the EWD (electrical wiring diagrams, available for download at this site) to get the pinout of the fuel pump, and jumper power across the pins. But if it's not a fuel delivery issue, then it doesn't fucking matter!

However, if this is a case of the fuel pump failing, 90% of the time when I had a fuel pump problem over the 3-4 dozen cars I've owned, I could get someone to slap the tank repeatedly while I turn the vehicle over and it would jostle the fuel pump into giving up another start or two.

But here's the thing: "Fuel delivery issue" means a shitload of things:

• Some electrical component is failed: Fuel Pump Relay, Fuel Pump Resistor, Crank Position Sensor (or its harness), EFI fuse, or even the ECU is toast (due to water intrusion from a windshield crack or bad seal, or just dead-dead) etc.
• Some electrical circuit is failed: Rodents nested on the tank and chewed thru wires, you ran a screw thru the harness that runs along driver framerail, corrosion inside any of the harness connectors from the fuel pump relay socket back to the pump, etc.
• The physical fuel pump is dead, which very rarely happens, and if it does, you can slap the tank most of the time as advised to get it to run a little more.

That said. Before you go any farther, get a can of starter fluid and at least confirm this is a fuel delivery issue. THEN we can try to help you step through testing. Otherwise you're liable to cause yourself a shitload of hours of labor and pain and money breaking out the parts cannon, or chasing down things thate aren't actually the problem. Can of starter fluid is less than $10 at any local auto parts store.

If you pop off your intake tube, open the throttle body plate, and spray a 1-2 second shot of starter fluid back up into the intake, and the truck doesn't start, this has nothing to do with your fuel system, which means any time you spend dicking around trying to diagnose why you're not getting fuel would be time wasted. Wouldn't you love to avoid wasting time here?

 

Sounds good. I'll give it a shot tonight.

 

Ok, so it started with starting fluid. It also stayed on for about 5-10 minutes (so obviously on gas), but was running very rough, with poor throttle response.

I checked the red MAF wire, and I was getting 10 volts or less (it fluctuated between 10 to 8 volts). Battery voltage was over 13v at the time.

I didn't have time to mess with it for too long. I did try to start it again and it was back to crank, no start.

 

Ok, that is weird. Just for shits and giggles, how old is the battery, and do you have the means to pull it and drive to a store to have them test for V, CA, and CCA, amongst other stuff? Just want to get clear on whether it’s actually good. 13v reading means nothing. Your alternator could be giving that reading.

Also, tell me this. Look carefully at your intake tube/intake assembly. Are all the vacuum hoses connected? Including the three that should be attached on the box portion of the OEM intake along the passenger side? One assists with raising fuel pressure by pulling vacuum off the intake. I’d ask you to check fuel pressure, but I fear it may beyond your scope, unless you tell me otherwise.

If your fuel pump was actually dead, the truck wouldn’t have run for 5-10 minutes after cranking with starter fluid. But you may have a fuel pressure issue (which doesn’t mean the fuel pump is bad). It could be someone replaced the OEM fuel filter with aftermarket and now it’s clogged … OEM fuel filter is VERY free flowing and rarely clogs, per our collective experience on the forum, it’s almost never the fuel filter. But Toyota does say it’s a maintenance item to change I think every 30k or something. It’s a BITCH to replace, and you should replace with OEM filter. Actually, fuel pump, fuel filter, and the air and oil filters for these trucks are best to use OEM (FYI: Denso brand is OEM for the fuel pump!!). I say that as a total freaking Wix junkie for my non-Toyota vehicles. Toyota designed their filters specifically for these engines, the engines just run better using their filters.

Some people are going to be shocked, but after confirming the battery is OK, I’d consider replacing the fuel filter with a new genuine Toyota fuel filter. Just so we can rule it out, it’s a cheap part to throw at this.

 

Should the MAF be seeing full battery voltage at the red wire? Also, if it makes a difference, I took that reading while the engine was running.

Would you happen to have a part number for the Toyota fuel filter? I always have trouble finding OEM part numbers for some reason. I know for a fact the one there is aftermarket, because I put it there (before I found out everyone says to leave it alone).

I'm pretty sure all the vacuum hoses are in place, but I'll double check them tomorrow.

 

Should be 23030-62010

https://www.toyotapartsdeal.com/oem/toyota~filter~fuel~for~efi~23030-62010.html

 

Awesome, thanks!

 

I see @BubbaW mentioning it should see 12v for a DC that's newer than yours. He also mentions the fuse EFI NO 2 should be supplying power to that sensor, so it could be curious to verify that fuse, and test voltage at that fuse.

And yes, I do find it weird the voltage tested lower than expected for you at the MAF connector. But I'm also not willing to say that's your issue, and not a red herring.

 

Need to check all of the ground wires and connections. Poor voltage is often ground related. There are a couple of places where the ground wires make contact that could be loose or corroded. The cables can have hidden corrosion. There are some of those open woven ground straps that can corrode and break completely.

 

I'll check voltage tonight. Previously I had just checked that the fuses were good.
I really won't have a chance to check for bad grounds until this weekend, but it's interesting that the previous owner had installed an additional ground from battery negative to the intake manifold. There might indeed be some bad grounds somewhere.

Does the 12v to the MAF come from the EFI 2 fuse?

 

That’s what BubbaW suggested in that thread I linked, but that was for a later model than yours. I would expect fundamental similarity but adding the caveat for full disclosure.

 

I'll try to find the MAF circuit in the FSM

 

Yes, via Black with yellow tracer wire feeds MAF 12v from EFI NO 2. You can find the wiring in the ENGINE CONTROL section of the EWD.

Brown is ground
Light Blue with Yellow tracer, Green with white tracer and Yellow with black tracer go directly to the ECU.

Honestly, I would try starting it with the MAF unplugged. It should start up but not idle worth a damn.

 

So, if I'm reading the wiring diagram correctly, power to the MAF comes from the EFI relay->EFI No2 fuse->junction connector->MAF, so that gives me the main places to check for voltage drop.

 

Unless I'm missing something, the 12v wire should be red

 

My apologies, I was looking at the 2004 EWD for wire color

 

Update: I checked voltage to MAF, and it's getting 12v. Idk why the first time I checked in was getting less than 12v. Could be a wiring issue or who knows. Anyways, I cranked it and it started pretty much normally, except it's misfiring on every cylinder (p0300 plus 301 to 308). I also got p0100 and 110, which are MAF codes. I checked the MAF per the FSM instructions in the Pic, and it "passes" both tests.

Based on the p0100 and 110 codes, I decided to try the other MAF I have, but also I disconnected the battery neg, and I'm giving it about an hour while I do other things. I'll report back what I findnwhen I put it back together.

 

I mean, I'm hopeful resetting will resolve things. Getting the MAF codes is suspect. Are you using a Hitachi (or Toyota) MAF, or some other shit brand? I can assure you, as much as people hate to accept it, these trucks HATE aftermarket store-brand parts. Toyota used Hitachi to make the MAF in these trucks, and it's geared to Hitachi's sensor. We've found people have problems with aftermarket coil packs, MAF, O2 and air/fuel sensors, starters, and fuel pumps to name the big ones.

Very few things can cause ALL cylinders to misfire.

• MAF is sending bad info to the ECU
• Fuel pump is not delivering enough fuel pressure to the rail (and/or the fuel filter is clogged, although that is VERY rare if you're still using the factory filter which is like a screen that lets lots of stuff pass)
• Both intake manifold gaskets are bad
• Major vacuum line disconnect or other vacuum loss
• Bad timing (how to check timing)
• Both upstream air/fuel (O2) sensors are bad and giving the ECU invalid data (which may or may not come with other codes)
  
• Some issue with the throttle body assembly or throttle position sensor, so the throttle isn't sending good info about how open it is (but that should come with other codes)
• Bad ECU, or wiring, or ground issue somewhere ....

It's a lot easier to diagnose this type of stuff when it's only one bank (one side of the engine) throwing misfires, i.e. you're misfiring on all odd (bank 1) or all even (bank 2) cylinders, or you're misfiring on 2-3-5-8, or 1-4-6-7 (those cylinder's injectors or coil packs are wired together in that weird order, IIRC)

 

So I put it all back together, and it ran for about 5-10 minutes without problems (I had other things to do). I still want to test it some more, but at this point I'm chalking it up to the MAF (both of them are Hitachi). I'm hoping it's not a MAF wiring issue.

Just to address some of your points, I did check for vacuum leaks by spraying brake cleaner all around the intake and all vacuum lines. The whole throttle body assembly is a year old Toyota unit that I had to buy when I first bought the truck. The fuel filter is new, but not OEM. I ordered an OEM one just because it's cheap, but haven't gotten it yet.

Originally I thought this was a fuel issue, because of the crank no start, but starting with starting fluid. I guess it may still be. I need to check it further, but this weekend I'm busy with my other truck (03 F250, bad front driveshaft u-joints), so I don't know if I'll be able to get to it.

 

There are a number of things that can go wrong to cause no fuel to pump. Many times if fuel pump is failing, someone can slap tank while you crank and it'll fire up.

Wiring is also an issue, corrosion can get into the connectors.

There's a lot of wiring, relay, fuses, resistor between the engine bay fusebox and the fuel pump that can cause problems.

There are possibly other things to cause the engine to crank but not start. Try something. Unplug your MAF and try to start the truck; will the '02 start without MAF attached? I have it stuck in my head either the earlier or later years won't start.

Other things can cause the car not to start or deliver fuel. Like, if the crank position sensor wire got nicked b/c it was misrouted when timing belt was changed last, the wires ca get eroded. I want to say the truck won't even crank if the camshaft position sensor(s) aren't available.

Lots going on with these trucks. It's worth grabbing the FSM from the sticky thread for new owners, and grabbing the EWD for your year out of the same thread.

 

Truck starts fine now. Idles a little rough but not horrible. I let it idle for about 30 minutes, them took itnfor a drive around the block.

It's very low on power. Feels like it's bogging down under load. This is the same symptoms (but worse) that caused me to clean the original MAF to begin with, and possibly fucked it up in the process. It's not throwing any codes right now. I had disconnected the battery prior to doing this, but I would think it would've thrown a code during that drive if it was a code situation.

I'm really lost on this now. It starts and idles fine, but bogs down under load. Fuel? Clogged cat?

 

Definitely not clogged cat. Possibly fuel delivery, but you’ll never know without measuring fuel pressure or pulling out the parts cannon, like throwing a new Denso brand pump and new OEM filter in. It could also be that the pressure regulator, or even a bad vacuum line. Could even be a bad coil pack but trying to isolate which is a bear, and these trucks hate aftermarket coils.

 

So, since I'm out of ideas at this point, I think it's time for the parts cannon to make an appearance. I don't have a realistic way to check fuel pressure on this engine (the SST is too damn expensive for something I'll probably just use once). My plan is to buy a cheap fuel pump ($30 from Rockauto) and if that fixes it, I won't mind buying an OEM one and doing the job all over. If it doesn't fix it, I'll put the OEM back in.

BTW, I can't seem to find a Denso pump. Everywhere I've looked they're out of stock, or discontinued. What's your opinion on Delphi pumps?

Also, I had ordered an OEM fuel filter, and then got an email because it was discontinued. Seems like a lot of these OEM parts are getting hard to find. That being said, the Wix filter that's there now it's only a few months old, for whatever it's worth.

 

You may just want to order an OEM pump. It’ll just be Denso all over again, at a premium, but trying to get fuel pumps and alternators direct from Denso has been difficult lately. I can pull
The part number for you if needed.

I don’t hate Delphi, but definitely prefer Other companies. Bosch. Standard Motor Products. Delco. I dunno what’s available for you. None is a sub for ORM though. OEM will always last you longer.