Please help - FJ62 Hard Start Issue (1 Viewer)

[JAX 1988 FJ62]

I’ve been batting this issue for the last 2-3 months and could really use some help.

Over the last few months it has taken multiple attempts to start (each 5-7 seconds) before the motor finally starts. Prior to that, it would start almost immediately upon cranking.

Once running, the motor runs very smooth and has no issues at idle or while driving.

I have done the following to diagnose:

- Cleaned and replaced cold start injector (made zero difference).

- Replaced the fuel pressure regulator with a spare that I had. (Made zero difference)

- Checked fuel pressure per the FSM
- With the service wire jumping the +B and FP terminals, I get 40psi.
- With the motor running, I have 42psi
- with the motor running and the vacuum line on the VPR disconnected, I have 49psi
- 10 min after shutting down, I still have 37psi.

Unless I am missing something, all of that appears to check out.

- The connector on the water temp sensor was very brittle/broken, so I ordered a new sensor and connector from @ToyotaMatt and replaced both. Unfortunately that did not fix my issue either.

At this point I am running out of ideas and would love the expert opinions on what to check out next.

Thanks in advance!

 

[JAX 1988 FJ62]

Update:

I replaced the fuel filter (no difference with issue)

I have a spare coil/igniter so I changed that out, as well as the wire to the distributor and that resulted in no difference as well.

Other ideas on things I can test? The truck runs great, but just takes too long to start.

 

[SteveH]

Trust, but verify.

I would remove the cold start injector, plug the manifold hole, (reconnect the fuel line to the CSI) and crank the engine, and see if the CSI is actually shooting out fuel during cranking. Use care not to catch the whole thing on fire. Alternatively, you could shoot some Ether into the manifold (any time the engine is cold) and if it instantly starts, it tells you that you have a fuel issue.

 

[toy_tek]

Confirm your timing and compression are within spec before replacing more parts.

 

[JAX 1988 FJ62]

Trust, but verify.

I would remove the cold start injector, plug the manifold hole, (reconnect the fuel line to the CSI) and crank the engine, and see if the CSI is actually shooting out fuel during cranking. Use care not to catch the whole thing on fire. Alternatively, you could shoot some Ether into the manifold (any time the engine is cold) and if it instantly starts, it tells you that you have a fuel issue.

@SteveH I think you might be onto something. I pulled the CSI and flipped it around. Had my son crank the engine and the CSI only put out one small bubble. I have two, so I’m going to deep clean both and see if either one behaves differently after that.

 

[toy_tek]

@SteveH I think you might be onto something. I pulled the CSI and flipped it around. Had my son crank the engine and the CSI only put out one small bubble. I have two, so I’m going to deep clean both and see if either one behaves differently after that.

Any update?

 

[JAX 1988 FJ62]

I was able to deep clean the cold start injector (again) but that did not make a difference. Still does not spray any fuel when cold starting.

I check the resistance on the cold start injector time switch and it measured 80 ohms which is in the proper range. I’m a bit concerned about the wire harness plug on the cold start time switch though. It’s very brittle and maybe it’s not making good connection to the sensor itself. Is there a replacement for just that female wire harness plug?

 

[JAX 1988 FJ62]

 

[Spook50]

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I would hit it and the connector on the switch both with a healthy dose of CRC Contact Cleaner (the plastic safe kind in the red can) and see if you can get a good electrical connection with it. You can verify if you have a good connection by checking where it connects to the ECU with an ohmmeter to be sure you have the same resistance there as you do at the switch itself.

 

[JAX 1988 FJ62]

I would hit it and the connector on the switch both with a healthy dose of CRC Contact Cleaner (the plastic safe kind in the red can) and see if you can get a good electrical connection with it. You can verify if you have a good connection by checking where it connects to the ECU with an ohmmeter to be sure you have the same resistance there as you do at the switch itself.

Thanks, I’ll definitely give the CRC a shot.

@Spook50 Do you happen to know where it connects at the ECU?

Edit: I did some additional review and see that it’s the STA and STJ terminals on the ECU. I’ll test there once this hurricane passes and I can get the CRC cleaner for the connections.

 

[Spook50]

Thanks, I’ll definitely give the CRC a shot.

@Spook50 Do you happen to know where it connects at the ECU?

Edit: I did some additional review and see that it’s the STA and STJ terminals on the ECU. I’ll test there once this hurricane passes and I can get the CRC cleaner for the connections.

Stay safe!

 

[cornboy]

Can I revive this thread as I am having the same issue. I have strong cranking but will not start in the AM. If understand the purpose of "cold start" to assist starting the engine which hasn't run in several hours and not necessarily the ambient temperature. Am I correct with this understanding?

 

[SteveH]

From what I recall, it's temperature based and only operates a low temps. Time to consult the FSM, I guess.