Vitara 1.6 8v running cool and over fuelling

[CopperBottom]

Hey everyone,

So im having an ongoing issue with my 1.6 8v which i need some guidance with

SYMPTOMS:

1: Coolant temp is way below "normal" operating temps. At no point during a drive or sitting idling does the gauge go a couple of mm passed the gap in the line just above the cold mark. The top rad hose does get warm, but not as hot as I would expect (i can hold onto the top hose for more than a few seconds before i have to let go) and the bottom rad hose is cool to touch. Heater matrix hoses are both hot.

2: Engine is over fuelling. ive had a couple of petrol head mates follow me, both say the exhaust stinks of fuel, and the engine performance is pretty gutless and is laboured through the rev range

WHAT I HAVE DONE:

I initially suspected that the thermostat had been removed as there was a small leak around the thermostat housing. Turns out there was a thermostat present and the leak was due to a aged rubber seal. Both thermostat and seal have been changed with OE items.

Ive flushed bled the coolant system, but im not entirely convinced its completely free of air locks and i dont think the thermostat is getting to the required temp to open. The thermostat housing is hot to touch, but ill borrow my mates IR Temp reader to see how hot it gets.

There or no other symptoms relating to head issues, no mayo on filler cap or dip stick, no foaming or fine bubbles in coolant, coolant is a good colour, no smoke of any sort out of the exhaust on either cold start or general driving. I havent done a compression test as of yet, but id expect an over heating issue rather than very cool running issues.

The heater does blow cold, but i believe this to be an issue with heater control as the slider doesnt have a full range of movement and both heater matrix hoses are hot. I have tested the matrix for flow and it flows fine

I initially thought it may be the temp sensor for the gauge, but the fact its over fuelling suggests the engine isnt getting up to temp. Odds on both gauge and ecu temp sensor being goosed?

Can anyone suggest any other reasons why it would be running cold and any possible remedies?

Cheers in advance

[ferris]

Water pump maybe??

[ScottieJ]

Bit of an interesting one as they usually overheat when there is an issue with the cooling system. Only things I can really think of is that the new thermostat is opening early or the thermostat is somehow being bypassed if something is plumbed up wrong?

[CopperBottom]

Re water pump, I'm confident it's working. Whilst I had the thermostat housing off, I accidentally turned the car over and it pumped a load of water out of the block.

I'm going to block up the face of the rad with a big bit of card to stop the viscous fan drawing air through the rad and see if I can get it hot enough for the thermostat to deffinatley open. Other than that I'm out if ideas

[ScottieJ]

If the thermostat wasn't opening it would be running hot.....sounds like you have the opposite problem that it's opening early/stuck open, not allowing the engine to get up to temperature.

Take the thermostat out and put it in a saucepan, heat the water up with a thermometer in so you know the temp and take a note of the temperature then the thermostat starts to open.

[twiss]

Also might be worth having a look at the clutch on the viscous fan...
when they break they usually don't lock the fan to the to the pulley and spin slowly, but I guess one could break and lock on and be spinning full whack?

RE the over fuelling
have you got a standard carb on it? if so its probably too cold for the choke to turn off, so the overfuelling will probably stop when the temp issue is fixed

[CopperBottom]

Will do. I'll test the old one that I took out of the car aswell. What's the opening spec on suzuki thermo's? 76c?

[CopperBottom]

Also might be worth having a look at the clutch on the viscous fan...
when they break they usually don't lock the fan to the to the pulley and spin slowly, but I guess one could break and lock on and be spinning full whack?

RE the over fuelling
have you got a standard carb on it? if so its probably too cold for the choke to turn off, so the overfuelling will probably stop when the temp issue is fixed

I'll have a look at the viscous clutch, good idea. Fairly sure it's spinning at slow rate (if it's anything like my 300zx, when it locks in you know it, sounds like a jet engine priming!)

Forgot to mention, it's a injection 8v, not a carb.

Also have mentioned it idles very low, circa 600rpm. By no means is it struggling at those rpms and it seems perfectly happy there (no hunting etc).

[ScottieJ]

I think 82/83* is the stock thermostat rating.

edit...this is from the samurai spi manual should be the same as the 1.6 is pretty much the same engine.

Thermostat.jpg (45.91 KiB) Viewed 9297 times

[Ladaman]

I'm sure once you sort the temperature out, and get it up to temp, the over fueling will sort itself out. My son has just had an over fueling issue on his MX5, and that was down to a dodgy temp sender. That has one for the gauge, and one for the engine management. The engine management one was faulty.