Hard to Start 3.4L

[peter.hulcup Lurker Find all posts View Profile Close peter.hulcup]

Hi,

I've got a 98 3.4L GXL Prado thats having problems starting. It has never not started, but it can take up to 10 seconds of cranking to fire up. Generally the longer it sits the longer it takes to start - eg 6 hours resting = 10 seconds cranking, 3 hours resting = 5 seconds cranking. If you start it, turn it off and start it up straight away, it starts no worries the second time.

The compression and fuel pressure have been checked and are ok. I have hooked up the terminals in the diagnostics plug to make the fuel pump run for about 10min before starting - made no difference. Also no difference between running off the sub or main tanks. As far as I can tell the fuel pumps and lines are ok. Have replaced fuel filter also.

The computer has not given any error codes.

Temperature seems to make a difference. I live in North West Western Australia where it is always hot (min 20 - max 30). I took it down to Perth during winter (10 min - 20 max) and it started ok! I changed the coolant temp sensor but it made no difference.

Its got new plugs, has done 140000kms and runs perfect once started.

Anyone got any ideas about what's wrong with it?

Peter

[dingo 01 Lurker Find all posts View Profile Close dingo 01]

It sounds a lot like a valve clearance issue but the comp test should rule it out . If you drive a lot in fine dust conditions it can really eat into your intake valve clearances . I`ve got similar problems with mine but mine runs on LPG which also plays havoc with valve clearance . The first sign of hard starting on mine I know it needs another tappet adjust .

[peter.hulcup Lurker Find all posts View Profile Close peter.hulcup]

Yeah, that sounds feasible. It does appear to be a fuel/air mixture problem and as far as I can tell the fuel supply is ok.

Does your Prado run rough or is it under powered when the valves need adjusting?

Is only a problem to start if it has been sitting for a while? ie a cold start.

How much does it usually cost you to have the tappets adjusted?

Thanks,

Peter

[dingo 01 Lurker Find all posts View Profile Close dingo 01]

A Toyota dealer will lash you 5 to $700 for a tappet adjust ( ouch ) I`ll be doing it myself next time . Hopefully I can get some help on this forum. It`s definatly harder to start when cold but the starter motor doesn`t sound like its fully loaded up which would indicate low compression . Once started the power seems ok but it idles rougher .

[Fazza Senior Member Find all posts View Profile Close Fazza]

Peter,
If your compressions are OK I would suggest you can rule out valve clearance.
If you have a mis at idle? have you considered a vacuum leak.

Most importantly, I would be checking the ignition side of things particularly Ignition module, Coil etc.

Hope that helps,
Fazza
07 GXL Auto D4D

[peter.hulcup Lurker Find all posts View Profile Close peter.hulcup]

Dingo,

Asked the mechanic to check it out when I got it serviced. They checked the compression again and reckon the valves are ok. It idles smooth too.

If you do end up adjusting the valves yourself, I've heard that there is a special Toyota tool that you can buy that makes adjusting the valves much easier.

Fazza,

Thanks for the ideas. I'll check those things out over the next few weeks and let you know how it goes!

Cheers,

Peter

[dingo 01 Lurker Find all posts View Profile Close dingo 01]

Thanks Peter
I was hoping there was a tool to compress the valve springs while the cams are still in place , thats probably the tool . It would be a huge job if I have to remove the cams .

[Jam Junior Member Find all posts View Profile Close Jam]

Re: Hard to Start 3.4L

Hi Peter,

Have you checked your glow plugs? :shock:

Seriously though, how old is your battery?

[Sole Lurker Find all posts View Profile Close Sole]

Mine is a petrol 4000 same problem had everything changed plugs injectors, cats, inlet valve any ideas it starts great first drive of the day but crap after sitting an hour but if you restart within 30 minutes stars fine is yours the same?