Hiccuping 4.2 D4D On Acceleration.

[rallying1]

F*&)&* ing hell its doing it again !!

I give up, 1 week, 1 bleedin week and now we are back to the same old problem, give me a break!

[igormus]

F*&)&* ing hell its doing it again !!

I give up, 1 week, 1 bleedin week and now we are back to the same old problem, give me a break!

hi matey

is engine well started and has stable idle rpm ?

check with el contacts of all position sensors, wires contacts to injectors etc. may be this minor issue create a head ache.

regards / Igor

[rambler]

F*&)&* ing hell its doing it again !!

I give up, 1 week, 1 bleedin week and now we are back to the same old problem, give me a break!

Hi Gary

I may in same boat as you my friend,mine hiccuped,kicked...what ever you wish to call it.

Mine has been ok for 4-5 weeks,but just started ever so slightly kicking again..only once on cold starts,at about same 3000 revs

I have had all those valves cleaned......but i did'nt clean the multiplug on the wiring loom...that plugs onto the MAF sensor....just did'nt give it a thought !.

THAT WILL get a blast from CRC cleaner in next few days....may make a difference.....

[rallying1]

I will give that a go thanks.

Igor I am not the best at investugating theses things, the engine is stable at Idle and I will check whatever conections I can thanks.

[rallying1]

Well folks here we are months on and still the same problem. Had the injectors checked, they are fine, had a fault with the 'injector driver motor'???? anyway supposedly sorted, but still as to this day it still hiccups and drives me insaine, I am about at the end of my rope with it now.

[anchorman]

Did you see if there was any air in the fuel?

[rambler]

I have got used to driving my rav under 3'500 rpm all the time now,its only when its not fully warmed up that its ' kicks & hesitates ' quite badly if i floor it for instant power.

Once its warmed up it seems ok but i always accelerate gently and have just got used to it.

So still as yet no fix for the kick issue for me,i just hope that keeping the engine under 3'500 rpm does'nt do it any damage,i just cant warrant giving it to toyota to sort out,as there is no fault light coming on,could cost ££££'s

Been driving it like this for a year now.

As long as it works,starts in mornings and gets me about..i'm happy.

[anchorman]

Did you ever get the fuel filter changed Rambs?

[Tech01]

Sorry to hear you're still having this problem. The symptoms also correspond to a blocked (or partially blocked) catalytic converter - the first exhaust box, at the front of the car. This contains a tiny ceramic honeycomb, which can soot up, even with regular motorway runs. Hesitation/surging is only evident at speed, or when trying to accelerate hard, or attempting to use high revs.

To check this, simply remove the exhaust system after the engine "downpipe" - i.e. remove the cat box and everything after. Test-drive the car (it will be surprisingly quiet) and see if you have the power back again. If so, is cat is blocked. Remedy: replace it, or break up and remove its contents with a long cold-chisel. It crumbles like hard meringue.

Chris

[anchorman]

You can break up the contents of the cat but don't remove it. Some owners have fitted straight through pipes but in forthcoming MOT testing in the UK, cars will be checked to see that the cat is there if it was built with one.

[igormus]

check with booster pump in the tank

[rambler]

Did you ever get the fuel filter changed Rambs?

Hi Anch's

Yes my local village garage changed fuel filter,air filter and cleaned both EGR and VSV valves back in early summer,they lowered the exhaust from the union and looked inside,said cat looked clear.

I did propose they smashed it out,but they refused on the MOT scenario you mention.

I trust them 100%,as have known them for years and a local car electrician friend of mine also deals with them,although they use pattern parts KDR ?

So......its strange,once the Rav has reached normal temp,its fine,its just during warm up & within the first 4-5 miles,if i have to floor during this ,i rarely take it above 3000-4000 rpm anyway.

Actually....thinking about it,it only seems to happen once , accelerating through the revs.....and once it has done its few seconds of hesitation and kicked a few times,from then on it seems fine.

I keep thinking turbo issues,but once engine is at temp,it pulls fine with turbo, ( i assume turbo kicks in about 3500rpm ? ) or does turbe run permanently ?

IF i slip the clutch during gear changes during this time,it doesnt hesitate...work that one out ?

[anchorman]

Try pumping the plunger on top of the filter. It should go stiff after only 2 or 3 pumps. See if it makes any difference.

[Tech01]

Hi Jamie,

I understand your hesitation in removing the contents of the cat, but it is still worthwhile to run the test for a blocked cat (i.e. remove exhaust and test-drive car), so at least you will know whether it's the problem or not. Having done the job, I discovered that just visually inspecting the front of the honeycomb (you can peer into it when the box is disconnected) doesn't reveal the full extent of any blockage. A pity a test-drive wasn't done when they dropped the front of the pipework.

Chris

PS Don is quite correct... By all means remove the contents, if necessary, but NOT the box!

[Awebb180]

Turbo runs constantly at a much higher rpm than the engine, around 10 times faster from memory. You should be on boost the point where the turbo kicks in hard by about 1500/1800 rpm and hold boost til 3500/4000 rpm.

Alex

[anchorman]

The turbo is working at all revs depending on throttle load. The pressure will vary considerably.

[igormus]

The turbo is working at all revs depending on throttle load. The pressure will vary considerably.

we must not to miss two matters as:

- turbo shaft simply rotates under gas pressure/flow giving no air pressure;

- turbo shaft rotates and reacts fast on gas pedal giving an air scavange pressure.

regards / Igor

[rambler]

Hi Chris

After all this...ive been looking harder at my driving style in last few weeks,the kicking issues seem to happen at between 2000 and 3000 rpm ( not 3000 to 4000 as i mention earlier ).

I have a week off work next week,so have some time to do stuff, ( provided it stays dry ), i wonder if i can drop undo the two union bolts at the front of the exhuast,somehow secure the loose exhaust up safe & high and take for test drive ,see if it makes a difference.

I will also try pressing that pump button don,see if it makes any difference.

Other than that,i'm considering my options and may give it to toyota to play with despite the expense......or as i have been doing,just live with it and accelerate very gently at all times ( more mpg, but no power when i may need it )

I just want it to run right.

[Tech01]

Hi Jamie,

What you suggest sounds a good idea. I can't see why you shouldn't undo the flange joint just upstream from the cat, and secure the pipe to one side. (Just make sure it is secured, otherwise the "pole vault" could be pretty serious!)

2000rpm is just a little over the point where the turbo starts doing some useful work (the turbo effect commences at 1650-1800rpm) and builds thereafter - at 2000-2200rpm it produces really helpful additional torque). 3000rpm is more-or-less the top end of the useful power band of these diesels; they'll rev faster, of course, but torque doesn't increase, quite unlike a high-revving petrol engine. So 2000-3000rpm is the rev range where you'll get most response.

A blocked (or partially blocked) cat usually shows up as a reluctance of the engine to go up the rev range at high throttle - i.e. the cat just won't cope with the high flow of exhaust gases. Instead of happily running to to 3000 or 4000+, it will hiccup and hesitate, and will appear to "strangle" or "run out of puff" at 3000 or so . . . almost as if the fuel supply is being restricted.

This may well be the case: hence the good advice to check that the fuel (and air) filter is clean. Also to check that air-flow and temperature sensors are clean, so that the ECU gets reliable and steady input readings.

I do wish you good luck with handing it over to Toyota. My experience here, about 3 years ago with exactly the same symptoms as yours, was that my local Toyota dealer wanted to fit a new turbo, a new catalytic converter, and a substantial section of the exhaust system . . . all at around €3000 . . . and without even taking the vehicle for a test drive! Amazing.

The car was taken to a respected and independent diesel injection specialist, who test drove it, and ran a computer diagnostic check. He certified the turbo system to be "perfect", but accurately diagnosed a blocked cat. This advice cost me just €45. Back home, we de-innared the cat, and all was then well. It might be worth your trying one of these specialists before Mr T.

Let us know how you get on.

Chris

[rambler]

Hi all

Well,havnt been on here for a good few weeks ( sorry ),but i seem to have cured the hesitation...( I hope ).

It seems to have been as easy as thoroughly cleaning the contact pins in the MAF sensor multiplug,i gave the loom plug a real flushing with Halfords electrical contact cleaner,same with the multiplug socket on the MAF sensor.

Did this twice a couple of weeks ago ( all in same hour ) let it all dry properly,and to be honest i just didnt dare floor for next few days,as was dredding it re occuring.

But in this last week,ive thrown caution to the wind,flooring it everywhere.......now ive got clean clear power all through the gears,all through the revs,all the time....its WONDERFUL.

Maybe those little pins in the multiplug just were'nt making ' contact ' properly and not sending readings from the MAF to the computer.

Anyway..............its all working properly again now........phew !

[anchorman]

I was just about to say check those plugs..............................................

[rambler]

I was just about to say check those plugs..............................................

Ha Ha

To be honest Don,i just cant believe that a bit of microscopic dirt can stop those brass contacts from sending and receiving signals,they are very well tucked away in that multiplug.

But.....it goes like the clappers now,i cleaned the contacts on a digital camera memory card recently,as my computer woudld'nt read it....this is where i got the idea from.

[anchorman]

Nice work Rambs.

[rallying1]

Going to try this with mine for sure before I push it off of a cliff, sick to death of it now, I also have the whooooo coming from the filter head too so I have that to deal with, merry Christmas!

[rambler]

Going to try this with mine for sure before I push it off of a cliff, sick to death of it now, I also have the whooooo coming from the filter head too so I have that to deal with, merry Christmas!

Hi Gary

In just the last few weeks or so my hesitation has re-occured,last weekend i again flush the MAF sensor and the mulitplug with the Halfords elec cleaner,but it still hesitates.....not as bad,but it still does,once its been driven for a few miles and fully warmed up its fine.

I may again invest in a can of CRC.. MAF sensor cleaner of E**Y ,its made for the purpose,its only a small can,but if it works better than Halfords stuff....its worth it.

The last time i used it,i used almost the entire contents on the sensor and multiplug,but it cured it until now.....ive bought 2 cans so far this this year,first time i just cleaned the sensor....got partial results,second time i cleaned sensor & multiplug contacts...,then it drove like new for about 3 months.....awesome !

Re fuel filter cap,i believe there is yet another superceded part number for an upgraded non howling cap.....but i cant be bothered,i live with it.