Intermittent 2004 LX470 Starting issue (3 Viewers)

[Grant LX470]

Hello, I have seen multiple threads on starting issues (sorry if this is a redundant post) but I was hoping to get some more specific advice with my vehicle if possible. I have a 2004 LX470 with around 170k miles and recently had an engine swap (a few months ago) from I believe was a 2003 tundra with around 130k miles. Since the engine swap, I have had an intermittent starting issue (see attached video link) where the truck will start, but has a very hard time doing so. The issue seems to only present itself when: I drive the vehicle for a bit (at least 20-30 minutes), turn the vehicle off and let it sit for around 30 minutes, then try and start it again (often when going into a store and coming back out). Furthermore, the issue seems to compound and get worse the more often the truck is started during the day. I have taken the vehicle to multiple mechanics (including dealership) and the issue has not presented itself to anyone, hence I have gotten zero answers/suggestions. The VSC lights have been attributed to a faulty oxygen sensor, which I am told has no relevance.

Starting Issue Video



Some work I have done recently in case it is relevant:

- Clean mass airflow sensor
- Clean Throttle body
- Replace idle up valve connected to power steering pump
- Replace heater Ts and hoses
- Replace Battery
- Ensured alternator is good


From what I have read, I think my next step is to replace the fuel filter and possibly the fuel pump?

Thank you in advance for any advice, it is greatly appreciated!

 

[jm34]

Wild. I just posted, what appears to be, the same issue with mine: 2004 LX470 False Starting - https://forum.ih8mud.com/threads/2004-lx470-false-starting.1363286/

I agree, I feel like my next step will be to replace the fuel pump. I had the fuel filter done only a couple months ago.

 

[TallyLC]

My 2000 LC does exactly the same thing. I have replaced the fuel pump and fuel filter, without seeing any difference. I also wrapped the fuel lines near the exhaust under the truck with heat shield tape. I have narrowed it down to a heat soak issue, probably in the engine bay. (I know I have a slight exhaust leak at the manifold.) It only happens after the truck has been running for a while, then parked for at least 5 minutes, but less than an hour. If I try to start it after 5 minutes, and less than 1 hour it sputters and coughs. My 2000 does not have the same start function as a 2004, so, I have to hold the key to keep it cranking. It eventually fires up and then runs without any issues. It always happens when it is hot outside and is not an issue when the ambient temperatures are colder.

 

[TahoeZ]

Sure sounds like vapor lock. Have you shot temperatures around the engine bay with an infrared gun when this happens? Is your fan moving air properly?

 

[TallyLC]

I don't think the fan is a problem. I have a scan gauge that tells me the truck sits around 196-200 in traffic, with the A/C on and gets up to 208-212 on the highway. I'm in Florida where temps are regularly in the high 90s. I think this is normal for these engines, right? I have 240,000 miles.

 

[AARONTLC]

I don't think the fan is a problem. I have a scan gauge that tells me the truck sits around 196-200 in traffic, with the A/C on and gets up to 208-212 on the highway. I'm in Florida where temps are regularly in the high 90s. I think this is normal for these engines, right? I have 240,000 miles.

That does not sound right. You are running hot. I run 186 to 191.

 

[TahoeZ]

180 -190 is normal operating temp.