Holding Back At 3000Rpm And Hot Starting

[yyaann]

Hello this could be a bit long winded but i hope it will save a lot of have you tried ........ questions.I have recently bought a 2001 rav d4d which had a new turbo fitted by the previous owner. After driving it for two days or so i noticed it's reluctance to rev higher than 3000rpm ish. Replaced pair of scv, no change so looked at dpf on exhaust and broke it out, that resulted in instant eml when revs climbed passed 3000 not having a fault code reader and lots of head banging later i found that when the turbo was fitted the vacuum pipes that regulate turbo had been fitted the wrong way round now it runs great and iam happy but there is another common d4d problem it is the hot starting issue.The engine starts when cold maybe a bit slow but it does start, when its up to running temp and is switched off and restarted straight away it will start but if left for between one and five minutes it will not start, cranking sounds very slow and almost like Battery or starter failure. The rav has covered 118000 miles uses no oil or water it has had a new fuel filter, genuine toyota, cleaned egr valve, new air filter, cleaned maf sensor and Battery tested, pumping fuel primer makes no difference, It has just been fitted with a recon starter motor which sounds no different to the original toyota starter but the company that it came from say's that on that year two types of starter were fitted the latter being .2kw higher output and they unsure if it would fit so i have the lower output motor. I have read many threads on this subject but found that there is no common fix so any help would be great.

[anchorman]

Put a moving coil volt meter (one with a gauge not a display) across the Battery terminals. It should read about 12v. Get somebody to crank the engine and it should drop to not less than 9.6v. If it does that starter is no good. Maybe you have one for a petrol engine?

[yyaann]

Thanks Don i will try the test you suggest if i can find a meter of that type. I should perhaps of mentioned that i have connected another Battery via jump leads and the engine cranks at the same speed. I dont understand why the engine cranks faster cold than it does hot when it should take very little to start when hot.I was also informed at a local injection center that if the Battery voltage drops below 10 when cranking electronic injectors do not work which contradicts the Haynes book that says 8.5 is ok. I have tried the test you suggest but only with a digital meter and the drop was from 12.7 to 9 when cranking.

[Tech01]

"... but there is another common d4d problem it is the hot starting issue."

Is this so? I haven't noticed contributions about it. I'm not saying you don't have the problem, of course.

My 2003 D4D can be a bit hesitant to start in very cold conditions (but always starts 2nd tweak), but on cool non-winter mornings the turn-over and starting is the same hot as cold: never instant, but always after about 3 secs of cranking.

Exactly how difficult is yours?

Chris

[yyaann]

Hi Chris i dont think my problem is unique to the rav but to the d4d engine as a google search for "toyota d4d hot starting" will confirm. As for how difficult mine is a trip to the local tip yesterday resulted in me sitting for fifteen minutes before it would start and a stall in traffic last week had to be bump started.

[hedleyf]

Worth checking the earth to the engine, maybe when it won,t start bridge a jump lead from the neg terminal on the Battery to a good earth point on the engine block, worth a try won,t cost you anything.

[thewingedavenger]

For the hot starting issue have you checked the output from the alternator. My son had a similar issue with his BMW. The alternator output was too high and overheating the Battery which would then refuse to sart the car. Voltage checks on the Battery were good but not enough to turn or start the engine. Replacing the alternator cured the problem. Max output should be around 14.2 volts, anymore than this means the output diode is fried.

[Tech01]

Hi yyaann,

I did Google "hot starting problems D4D" as you suggested, and turned up a good few incidences of same. Looks as if Avensis can suffer this too.

More than one post pointed towards a starter motor problem, cured by either expensively replacing, or simply by a stripdown and cleaning out. Bit puzzled by this...

- Perhaps the s/motor was in such bad shape it was turning the engine so slowly that the compression rise was too slow to produce the necessary temperature in the combustion chamber for fuel ignition.

- Or was the inside of the s/motor sprayed with carbon/copper, so that it pulled additional current, thus dropping the Battery voltage, and sapping both glow-plugs (not needed much with a hot engine) and/or injectors?

Another cause for difficult starting (apart from the obvious checks on fuel filter, glow-plugs, etc etc) is air getting into the fuel, on the supply side to the fuel pump and common rail. This can be detected by inserting a short length of transparent tube before (and after) the fuel filter, and watching for bubbles there. Diesels just don't like air in the fuel. Common causes for air ingress is a loose coupling or pipe-seal, and a common culprit (not notably on the RAV) is the fuel filter itself. If an engine starts reasonably well when cold, but is difficult hot, it suggests "thermal upset" - ie something happening under the bonnet when things get warm . . . like an aggravated air/fuel leak. Fuel heaters (heat exchanger) can also go 'porous'.

IIRC, there is also a fuel pump in the fuel tank. This delivers fuel to the engine bay (to fuel filter), and operates only when IGN is switched on and engine is started up. It is there to ensure a deliver of fuel "uphill" to the fuel filter from the underfloor tank, and is not needed when the engine is running (the main engine fuel pump provides suction then).

Some other posts have hit on one/more injectors being the problem. Apparently expensive to replace, but I guess easy to have overhauled by a diesel specialist (typ. €75 for 4, out here).

Glow-plug operation? The Toyota workshop manual details how long these should operate for at varying temperatures: lengthy in the cold, v.briefly when hot. Check what these are doing with a temporary test lamp connected between the plugs' feed cable and earth.

What happens if you try to restart after only switching off for say 1 minute? Starts instantly?

Hope helpful,

Chris

[yyaann]

Hi Chris i have found similar results but no common fix or pattern to suggest a certain area in which to concentrate. I have striped and cleaned the original starter motor with no improvement so it was replaced with a remanufactured unit again no improvement. I have also checked the alternator output and fitted an extra earth strap from the Battery to the engine block just below the starter as suggested above again with no impovement. I do feel that you are right in suggesting that it is heat related as it starts fine when cold, when switced of it will start straight away if i leave it for 2 or 3 min cranking becomes very slow almost as if a sensor or something is lying to the ecu and the engine parameters are not correct for the current engine temp. If left for a futher 5 or 10 min it will start ok. In my opinion (i may be wrong) the actual engine temp would not change much between the time that the engine is switched off and 10 to 15 min later. Unfortunately i am almost at the point of offering it to a injection specialist with an open cheque book.

[Tech01]

Hi yyaan,

It sounds as if you've pretty much done all the right things in the area of the Battery and starter motor. Looking again at your original post, I've also noted that there were two types of starter motor fitted to the D4D. My Toyota manual lists these as 1.4kW and 2.2kW. Not sure whether the latter replaced the former (perhaps Kingo or Anchs will know), but presumably both work ok, otherwise there would be vast numbers of complaints. But I think this is probably academic.

If engine starts ok when cold, there is nothing wrong with your Battery, starting circuit, or glow-plug system. This is when all these have to work hardest.

My money would be on something being upset by the temperature rise which will take place under the bonnet pretty quickly (i.e. after a minute or two or three) after switching the engine off. (I've noticed that my "outside temperature" indicator on the dash will display accurate figures before starting, and while driving around. Park up, however, and on restarting, the temperature indicated can be anything up to 10'C above ambient. Drive a km or two, and it comes back to accurate. I think the "outside temp" is actually taken from the air-intake temp. sensor, which heats up nicely when parked up with a hot engine.) After switch-off, the engine block temperature will not increase, but that of all the under-bonnet bits will rise considerably - hot lump, and no cooling fan or forward motion to take the heat away.

I would now try:

- checking fuel line for air in it (when engine hot) - maybe a leak that worsens when hot. NB The fuel line from tank to injection pump is operating UNDER SUCTION when the engine is running, and after the tank pump has shut down. A leak in this line, or a bad joint, will cause air to be sucked IN, rather than fuel to be leaked out.

- getting the car into a diesel injection specialist, to check the above (if you can't), and to check and service the injectors. This is preferable to simply booking it into anywhere else, IMO.

Keep us posted.

Chris

[yyaann]

Hi Chris thanks for your input up to now

I havent looked for air in the fuel line from the filter to the injection pump but on two occasions when i was in the not starting time zone (2 to 3 min) after stopping i have pumped the fuel primer until hard and tried to restart with no success. Do you think that air entering the fuel line at this point would cause the engine to slow so dramatically on cranking.

[Tech01]

No, you are right: Air in fuel line would cause lumpy or difficult starting, but would not cause starter motor to crank engine slowly.

If starter turns engine slowly after 2-3 minutes, then maybe

- The engine becomes "tight" when hot, after switching off [but why?]

- There is a drag on the engine [Clutch/gearbox drag??? Try depressing clutch when starting???]

- There is still a poor electrical connection in the starter circuit somewhere, aggravated by heat [but you've checked all this out]

- After switching off, the Battery is subjected to an appreciable heavy drain, which, after 2-3 minutes is enough to compromise cranking [Heavy drain... Glowplugs come into operation after engine switches off? Alternator fault - alternator drains current from Battery? Cooling fan(s) staying on?

Use a hefty ammeter on a Battery terminal to see is there is any discharge after you switch off.

eg One of these...

http://www.justoffba...-Sealey-BT98-11 ]

- Faulty starter motor . . . or maybe your lower power version just can't crank a hot engine?

- Glowplug circuit not operating correctly when hot.

Still trying.

Chris

[hedleyf]

Is there some way that the rpm can be recorded/measured, if you could check the cold start rpm and then recheck it when trying to start from warm to see the difference, I think of the top of my head a diesel needs about 450 rpm to build up the heat required to start, this will rule out the cranking system .

[Tech01]

Not easy to check the cranking rpm without something like a hand-held optical tachometer. I'm not sure what the cranking rpm should be - Toyota workshop manual doesn't specify it - but I guess it would be below 100rpm ??

If you needed to know the speed of cranking, you could paint a marker on one of the engine pulleys (ideally crankshaft, but maybe one of the others, and calculate as necessary for diameters), and count the revs while cranking. Maybe.

Page SS-21 in RM856E (engine service manual) details, for the starter motor:

Rated voltage and power: 12V 1.4kW 2.2kW [ie the two types of starter fitted]

No load characteristics: 1.4kW type, Current 90A or less at 11.5V 2.2kW type, 120A or less at 11.5V

rpm: 4000 rpm or more

Page DI-19 in same pub. (troubleshooting):

Hot engine (difficult to start) . . . Check:

1. STA signal circuit [signal to ECU]

2. Injector

3. Fuel filter

4. Compression

5. Engine ECU

6. Supply pump

7. Fuel pressure sensor

8. Diesel throttle

Lengthy list! If it's a sensor or signal failure, I guess you'll have to enlist the help of someone with a diagnostic reader. Personally, though, my first port of call would still be a diesel injection specialist, where you wallet would probably be better protected. A good one will have an array of test/diagnostic tools anyway, but won't be hellbent on selling unnecessary bits.

Chris

[yyaann]

Hi everone i am sorry to say i had to admit defeat today as the rav was becoming a liability if stopped in traffic or if i needed to stop off somewhere quickly, so it is now in the hands of diesel injection specialist.

Whatever the outcome is i would like to thank eveyone who has contributed to help fix this problem, especially Chris who has obviously spent some time researching possible fixes,

I will post the outcome of the issue.

Thanks everyone Yan.

[Tech01]

No defeat . . . Just the most sensible thing to do next!

Looking forward, like you, to discovering exactly what the problem is.

C.

[anchorman]

It is not uncommon for starter windings to break down with age. As they do the cranking speed becomes slower when hot and the test is with a volt meter to measure cranking voltage. The instructions are in post 2.

[yyaann]

Ok so here is the latest and maybe the last installment of this saga, three weeks have passed and the rav has been with local diesel injection speciallists and their results were no faults found with injection system but in their words the engine becomes tighter when hot.

Great news for three hundred quid,so i now have the rav back and have fitted the largest Battery that will fit in the tray about eight hundred amps i think, this had no effect on the starting problem.

Next i returned the 1.4kw recon starter to the supplier who was very understanding to my situation and was happy to exchange it for a 2.2kw motor which works out to about 70% more powerful, WOW what a difference it now starts at the same speed hot or cold and no longer sounds like it not going to start.

The only down side to fitting a 2.2kw motor is that it may have to be removed to change the scv, a small price to pay considering.

Thanks again to everyone for their help and maybe this will help someone with a similar problem.

[Tech01]

Hi yyaann,

So, at last, a result! Well done.

During our correspondence, I had made some background enquiries about the RAV 2.0 D4D being fitted with two types of starter motor. The Toyota workshop repair manual simply details both (1.4kW and 2.2kW), but I've been unable to find out WHY two types were fitted...

- ? different markets (eg cold climates and hot?)

- ? did the 2.2 supersede the 1.4? Insufficient power maybe?

- or...

Perhaps someone can shed light on this.

The diagnosis you got from your diesel specialist is at least helpful . . . the engine is stiffer when hot. Perhaps just a matter of the compression being better when warm (lubrication on the rings, etc etc.), rather than an electrical problem. Looks as if, in your case, the extra power of the 2.2kW starter is essential.

I'm impressed with the 800A of your new Battery. It should serve you well.

You got there, finally!

Best regards,

Chris

[rambler]

have had this same issue with mine in last few weeks ,now i know what to do ,many thanks