First gen long crank when hot

I tested it, and it is fine. I jumpered across the plug and drove it for a bit, it still took longer to start.

I do think it is fuel related. Sometimes when I start it hot, it will crank and “miss” before finally starting. Like it’s not getting enough fuel. I guess I can hook up a fuel pressure gauge to see what the pressure is at the rail.

 

Is it just me or is a 2-3 second start not normal? To me, a long crank would be longer than that but that's just me.

 

This would be the next step to take in diagnostics.

 

Did you guys ever figure out a solution? I have had the same symptoms for about two months now and it has progressed to misfire type of symptoms. Also, is not wanting to accelerate t all when i hit the gas it is very delayed. Leaning more towards a timing belt replacement. Help?

 

Welcome! Sounds like you could have a blown head gasket. What model and engine? Last fuel pump swap? Any recent work? Check for fuel pressure yet? Ever clean or replace injectors? More info. Is helpful.

 

Could very well be a coil/plug misfire issue, or fuel pump.

Why not create your own new thread to give us symptoms and more info on your year of truck, engine, cab type, and what work has been done on it, and last time the timing belt was done (needs to be every 9-10yrs or 90-100k miles) so we can help you better? Instead of hijacking this thread…

 

I’m having this exact same issue please help me idk what it is!

 

I'm going to start my own thread, but I'm bumping this thread because I'm having a similar issue. Like a few have said and 2 in this thread, I keep seeing a lot of of threads, but very few solutions

On a side-note, my neighbor's first GEN tundra does the same thing but much worse. I think theirs does it cold or hot.

 

Hi everyone.

Exactly the same issue as the guy who started this thread.

All of the above checked and replaced.

Any conclusions?

2000 4.7

Thx

 

A couple years ago while I was reviving mine I experienced this same issue. I had been through the entire fuel system due to a rusted out tank. It was ugly. New tank, new pump, flush all lines-rails-injectors, new fuel filter (btw F that filter). New coils and plugs. Tested resistor (finned one mounted on fender). Pressure was constant 45psi. I did all this in 21 so I might have forgotten some things. But my main focus wasn't solving the hard start when hot issue. That came about after I actually got her road worthy. But one thing is I'm in Michigan so we certainly don't get the heat you souther guys get, and I'm a relatively short tripper, very few miles (not much in and out running errands with it). At one point I think I reasoned it out to a few leaky injectors (295k on them) dripping and flooding the restart. No conclusive evidence, just a guess.
@shifty` makes a great point about resistive circuits and heat. I think we have several relays that are the same in the underhood fuse box so swapping a couple of those would be another test.
I think I just got used to it and moved on with life though
How about you @Weagle ?

 

Could really use to know more about what you've done so far, where you got your replacement parts, which parts you replaced, but I'm not going to ask you all that. I have a single question before going on.

If the truck always long-starts when it's hot, what happens if you get it hot to the point it should long-start, then spray starter fluid (Ether) into the intake manifold via the throttle body? This only requires that you pop the intake hose off, carefully push open the butterfly, and shoot a 1-2 second shot of Ether back into it, loosely pop the intake on, then go turn the key.

You can buy Ether in a can at the store. My preferred flavor is below.

What the hell am I on about with this question?

First, this shit is safe for your engine. If your truck starts up immediately after spraying it into the intake, you have a fuel delivery problem. If you still have a long-start with this in your intake, you have an ignition problem. Any time you cannot start, but the truck cranks, it's imperative you figure out: Do I have a fuel delivery problem, or a spark delivery problem?

If you can figure out which one it is, we can try to help you isolate the issue. But until we know which one it is, we're going to be sitting here throwing wild ass guesses at you, as we do with most fly-by-one-time posters that hit us up when their truck is broken.

​

 

Appreciate all your quick response.

Its my first question on this forum, but I'm following you guys for years.

Ether - I understand what you wanna achieve with that test, I will try, but no, i don't experience the "long start" every time, its mostly about outside temp and not the engine temp.
So its hard to predict and know if the spray made any difference.

Just to save all the suggestions again, I already replaced:

All the vacuum & vent hoses.
PCV.
All Evap valves.
Timing.
Fuel pump + new relay.
Fuel Filter.
Crank Sensor.
Spark plugs.
Both coolant temp sensors.
Canister.
Gas cap.
Cleaned the MAF.
bypassed the pump resistor.
Fuel tank fill hose.

I'm thinking about Cam sensor and ECM

Because the guy who started this thread had exactly the same symptoms, i thought maybe he solved it.

Thx

Don

 

I don't like to pull out the 'parts cannon' and start blasting parts at stuff without having some sense of certainty about the potential part causing the issue. Is it spark? Is it air? Is it fuel?

While an ECM or a crank position sensor don't cost an exorbitant amount of money, probably $100-150 for each for quality, authentic part if Denso brand (as it should be) depending where you source, I would prefer to know: Is it fuel delivery, or is it ignition?

Camshaft pos sensor... I would definitely pop off the driver side timing cover (be careful not to lose the bushing/inserts in the bolt holes) and verify the wiring isn't shredded inside or out, since earlier years seemed to have an issue with the part design and the cam pos sensor wire would get shredded behind the cover.

As you say the issue is tied to ambient temp/heat outside, it's interesting, I'd also have the MAF and maybe the IAT higher up on the list than the camshaft pos sensor and ECM. Heat/expansion impacts resistance-based hardware/circuits, so those are things I typically look at. It could also be interesting to see what the ECM's coolant temp sensor (there are two on passenger side of engine, ECM one is green) is doing/reading.

If the ether test proves slow start, i.e. it's ignition-related, that's when I'd be more suspicious of the ECM.

Sadly, like so many folks whose first post is a plea for help, it would appear @realtormarcos was a fly-by-nighter looking for a quick answer. He hasn't logged in for more than 4 years. 9 times out of 10 when a person's first post is a help request, they disappear within 1-2 weeks.

​

 

isn't the IAT is a part of the MAF on the 2000 4.7 v8 tundra ?

I will check the coolant temp reading ( I replaced both of those sensors )

 

I believe it's fully integrated in all years for our trucks, yes. The only other things between MAF and intake, I believe, are the throttle assembly, which contains throttle position sensor, and then the MAP sensor? I'd need to dig up the FSM. You know there's a copy of the FSM linked in line 4 or 5 of the "so you just bought a 1st gen" sticky thread, right?

 

That’s correct @shifty`

 

Update:

I check the coolant sensors ( both are new from Toyota ) and the reading was good.
I replaced the MAF 2 weeks ago, and till now the check engine light is still off

I cannot check the long cranking due to low outside temp, but I will keep you posted in a couple of months.

*Shifty - Don't add me to the "First post cry for help - disappear" list

 

We’ll know for sure in a couple months….

 

If a crank is taking too long, turn it off, then turn it back on.

 

we're talking about an extra second 2 max

 

So,
After replacing the MAF and both coolant temp sensors, clearing all the codes.

I did got the check engine light back on after 2-3 weeks of driving with one code: P0441 Incorrect Purge Flow
And also getting long starts in places with warm outside temperature. ( on second attempt its fires up in half a sec )

Any ideas on how to continue?

Already replaced:

All the vacuum & vent hoses.
PCV.
All Evap valves.
Timing.
Fuel pump + new relay.
Fuel Filter.
Crank Sensor.
Spark plugs.
Both coolant temp sensors.
Canister.
Gas cap.
New MAF.
bypassed the pump resistor.
Fuel tank fill hose.
Checked compression.

 

Given everything you've replaced, the only thing that would make sense to me is whatever sensor detects pressure is bad or reading off, you have a hole or crack in your tank somewhere. P0441 is more about incorrect purge or hold, or potentially a small leak.

Stupid question, but before you broke out the parts-cannon, did you smoke test, both using the port in the engine bay, and firing off smoke at the gas tank? (Cap fitting)

 

I did a smoke test from the engine side port. ( Found nothing )
I did NOT tried from the tank filler side.

Do you see a connection between the code and the long starts?

Thx

 

Are the long starts due to low fuel pressure at start time?

 

I don't know.
Do you recommend a mechanical gauge? or that's something I could read on the data stream?

 

I'd probably want a mechanical reference, personally. And I'd want to have someone else crank it so I could watch the gauge when it's cranked from dead cold, after sitting overnight.

 

My 2008 with 4.7 is doing this exact same thing. Crank, no start when warm. Always starts perfect on cold start though. Runs like a champ once started too. Replaced MAF, coolant temp sensor (only one, didn't realize there are two until now), new injectors, plugs, coils, o2 sensors. No CEL and no stored codes. Took it to a shop but it didn't misbehave for them. I am going to keep digging into it until I find the issue. New rigs are expensive. Gotta make this one last.

 

DI-374 STARTS ON PAGE 644 OF THE FSM
DI-266 STARTS ON PAGE 536 OF THE FSM

 

Awesome resource, thank you for posting this. It will help me a lot.

 

Any tip on where and how to connect a mechanical fuel pressure gauge? I haven't seen any fittings.
Thx