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Just picked up a 1988 4Runner SR5 w/ the 3.0 3VZE motor.
Runs well for its age, but there is an intermittent problem getting it to start.
It will crank just fine, but it won’t always fire up. Sometimes it takes a few tries, sometimes I have to give a little gas, and sometimes it catches the first time.
I took it to a mechanic yesterday but it wouldn’t reproduce the problem. Of course today, it’s right back to doing the same thing.
What I’ve noticed is that it fires up right away if it’s really cold outside.
Ive had a few things done to it and the problem isn’t as bad as when I first bought it. The cold start valve has been replaced, the tps adjusted, new plug wires and plugs gapped, cap, and rotor button.
The mechanic said the fuel delivery was fine.
There is a check engine light on that the previous owner said was the mass air flow sensor.
However, I got codes 51 and 52 when I jumped the diagnostic plug. 52 indicates knock position sensor. 51 has different meanings so not sure.
Right now I’m not sure what it could be. I’m sort of a noob with car mechanics, but was wondering if anyone has had a similar problem or have an idea what could be causing this.
Thanks for any suggestions you can offer.
Last edited by gilesitis; 11-17-2018 at 01:01 PM.
Reason: Add more info
So are you saying that dead cold, it will fire every time without issue, but when it’s a warm or hot restart, that’s when you begin having issues?
Yes, basically that’s what I’ve noticed. We’ve had two really cold days and it had little trouble starting on those days. Otherwise it takes a few cranks or some gas to fire. Occasionally it will fire the first time on a warmer day.
This code shows up if you turn on the AC or move the throttle while in diagnostics mode.
If you did neither of those things, preform.tps inspection on the IDLe circuit.
Not starting when warm is a known issue with the fuel delivery (there are TSB that cover this) and the FPU system. Or bad cylinder compression, thermal expansion ect.
This code shows up if you turn on the AC or move the throttle while in diagnostics mode.
If you did neither of those things, preform.tps inspection on the IDLe circuit.
Not starting when warm is a known issue with the fuel delivery (there are TSB that cover this) and the FPU system. Or bad cylinder compression, thermal expansion ect.
thanks for the advice; mechanic seems to think fuel delivery is okay but not ruling that out. It has been running rich, but not sure if that’s related.
thanks for the advice; mechanic seems to think fuel delivery is okay but not ruling that out. It has been running rich, but not sure if that’s related.
Inapect and clean the thermostat switch for the FPU system located on top of the thermostat housing. Ensure you have a good ground system from there to the battery. Inspect the wire from switch to ECU. There is also a VSV to inspect, it's the one that ties into the fuel pressure regulator. And of course the vacuum lines are routed correctly nor leaking.
If you go thru all that and find nothing that makes it better you need to actually test the fuel pressure. Cold vs hot and FPU system active vs disabled.
...
These aren't as susceptible to heat induced compression loss as a rotary engine but still might want to check the compression (cold, hot, dry, and wet with a squirt of oil in cylinder).
Inapect and clean the thermostat switch for the FPU system located on top of the thermostat housing. Ensure you have a good ground system from there to the battery. Inspect the wire from switch to ECU. There is also a VSV to inspect, it's the one that ties into the fuel pressure regulator. And of course the vacuum lines are routed correctly nor leaking.
If you go thru all that and find nothing that makes it better you need to actually test the fuel pressure. Cold vs hot and FPU system active vs disabled.
...
These aren't as susceptible to heat induced compression loss as a rotary engine but still might want to check the compression (cold, hot, dry, and wet with a squirt of oil in cylinder).
Appreciate the suggestions! Will check into those things. Do you think the knock sensor may be bad with it throwing code 52? Seems to make sense as I believe it’s supposed to increase fuel mixture (running rich) to prevent detonation (trouble starting)
Appreciate the suggestions! Will check into those things. Do you think the knock sensor may be bad with it throwing code 52? Seems to make sense as I believe it’s supposed to increase fuel mixture (running rich) to prevent detonation (trouble starting)
We see wire disconnected or damaged more than the sensor failing.
3 months later update: Still having the same issue with inconsistent starting.
On cold mornings/days fires up first crank (almost every time).
Warm days it's a struggle to start. Will start everytime with a dose of starting fluid.
Jumpered Fp to +b and listened under the hood. Sounds like plenty of fuel is coming in. Would not start however with Fp and +b jumped.
Engine compression test was good. Only DTC I'm getting is 51 (code 52 just went away).
I'm starting to wonder if it's the FPR or somehow related to code 51.
Any other thoughts?
Do you know how code 52 went away? That code doesn’t usually fix itself.
You should get a fuel pressure reading while it’s in a no start condition. There’s a write up floating around somewhere on how to do this on the 3VZE.
Do you know how code 52 went away? That code doesn’t usually fix itself.
You should get a fuel pressure reading while it’s in a no start condition. There’s a write up floating around somewhere on how to do this on the 3VZE.
I can't think of why that 52 would just go away, but it's gone. The only I've done since I last saw the code was put in new plugs, get an exhaust leak fixed, and run a couple of fuel cleaners through the tank...
What's weird is after the first time I reset the battery, I was getting code 22 or 11 (couldn't tell the difference). But that was the only code I was getting. Now that code went away and I'm back to getting 51 only.
Thanks for the tip about fuel pressure testing. I am a little confused about the different types of adapters, etc you have to have on the 3VZE.
The installation:
The banjo bolt next to the FPR is replaced with the connector. As you can see, the connector can be "permanently" installed (the crush washers on either side of the banjo MUST be replaced each time, so using a loaned tool has its drawbacks), with the gauge removed when you're done with it. So it's worth buying the connector even if you borrow the gauge.
RAD4runner (and others) on this forum have installed permanent gauges on their CSI connector. That's fine if you don't have other vehicles that could benefit from fuel pressure testing.
The installation:
The banjo bolt next to the FPR is replaced with the connector. As you can see, the connector can be "permanently" installed (the crush washers on either side of the banjo MUST be replaced each time, so using a loaned tool has its drawbacks), with the gauge removed when you're done with it. So it's worth buying the connector even if you borrow the gauge.
RAD4runner (and others) on this forum have installed permanent gauges on their CSI connector. That's fine if you don't have other vehicles that could benefit from fuel pressure testing.
Thanks Scope!
So the loaner from AutoZone should have all the connections I need right? I will just need to buy new crush washers for when I put on the tester and then when I put the original bolt back?
11-17-2018, 11:36 AM
