DrftKingIII

I'd like to get a bit of insight from someone with a bit more knowledge than I. Here is what happened:

1JZ, mostly stock except intake/exhaust/FMIC/EBC. The car has been blowing a heater hose off, the one that wraps behind the head from one side of the block to the other. It's blown off a total of 4 times now, all under cruising conditions/out of boost. Previous owner had a metal tube on it with no flared ends and crappy clamps. It is now fixed.

This past time, I was on the highway doing about 60MPH and it blew off. As soon as I heard/smelled/saw that it came off, I instantly shut the car off and coasted it off the highway onto a side road. I managed to get it back together and fill it with distilled water enough to limp it 5 miles back to my house. I did notice on the way home that my AFR's were almost constantly maxed at 16 all the way home. I fired the car up for the first time in two weeks yesterday and topped off the coolant/water and it was idling between 12-13 AFR's. As soon as the thermostat opened and the car was starting to warm up and the idle dropped, I checked the AFR's and again, it was maxed out at 16 just at idle, so I shut the car off. The first three times the heater hose blew off, after I temporarily fixed it and moved the car, the AFR's were fine. Thinking this last time was the final blow on the head gasket, but wanted some more experienced insight from someone who may know.

Let me know what you guys think!

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DrftKingIII

To the top!

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OBEEWON

It seems to me that you have exhaust gasses leaking into your coolant and you have massive air bubbles in your coolant. It wouldn't take much RPM for that to happen if the gasket was leaking. When an air bubble is at the waterpump there is less parasitic drag on the engine so the RPM raises. Once the coolant reaches the pump the RPM drops as the coolant puts a slight bit of load on the engine.

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DrftKingIII

Thanks OBEEWON.

Fired the car up again today and let it run for about 10 minutes trying to get any bubbles out of the system, but nothing major came up. Still having the same problem with the AFR's maxing at 16. With slight throttle, holding the car at about 3500 RPM's, the AFR's go into the 14's but it sounds like there is a slight misfire. As soon as throttle is released, AFR's head straight back to 16 at idle.

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supersayianjim

do you have an adjustable fuel pressure gauge??

and follow my work log for lean conditions.

http://www.clublexus.com/forums/buil...ct-soarer.html

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http://www.240sxforums.com/forums/rb...ject-s-rb.html

ixfxi

If thats the case, why not perform a leak-down test?

Simple question, did you ever remove the coolant hard-line and give it a proper bead so that the hose does not slip off?