Somethings still not right...

[clivvy]

basically, the running "problem" i have had forever is still with me. Its basically only at idle where it seems to dip and level back out within a few seconds, seemingly randomly.

Now, I jet washed the cars Saturday, and blasted the underneath a little. When it was dry, I ran themaverick again at idle, and when I pushed and held the break pedal down, the weird idle thing came about except itwould drop for around 4 seconds, sort of as if it was going to stall? then rise back up, and repeat untill I let go of the break.

Later, when I knew it was dry, I tried again, nothing. took for a quick drive out the back again nothing, all ok, any ideaS??

 

[Darwin]

basically, the running "problem" i have had forever is still with me. Its basically only at idle where it seems to dip and level back out within a few seconds, seemingly randomly.

Now, I jet washed the cars Saturday, and blasted the underneath a little. When it was dry, I ran themaverick again at idle, and when I pushed and held the break pedal down, the weird idle thing came about except itwould drop for around 4 seconds, sort of as if it was going to stall? then rise back up, and repeat untill I let go of the break.

Later, when I knew it was dry, I tried again, nothing. took for a quick drive out the back again nothing, all ok, any ideaS??

this has been mentioned before

cuts throttle while under breaking ?

 

[clivvy]

not quite. Lets put it this way, not once has it ctalled or anything under breaking. This is the first and only tme so far it has doen this weird thing at idle when I have pressed and held the break. At all other times it just doesnt seem to idle correctly, its really hard to explain! it sjust worried me yesterday that it did it, and the only explanation I could think of was I had jet washed something and caused a problem...but even if I had, say, a corroded break pipe, that wouldnt cause the engine revs to dip...its almost as if jetwashing the car underneath a bit has exaggerated my long standing current problem..which is the unevan idling...

 

[mickmonk]

Hi,
I dont know much about our trucks as I'm new, but it sound like some engines I've had that have been sucking in air. eg loss of vacumn

 

[kawa111]

my brother had 2 terranos and when i got mine there first thing he said to me was never wash the engine compartment as both of his ran really rough after he d washed them, he never did find out why

 

[clivvy]

i havent washed the engine, just blasted under the sills/exhaust area, you know, just knelt down and waved it under there a bit, didnt go near the engine.

I have begun to suspect some sort of vaccuum leak though, but i dont know what pipes to check! They all look in tact to me, but I havent yet inspected properly...

 

[Muckypup]

Mine does exactly the same occasionally, and I never wash it! :lol

Sometimes idles really low, and nearly cuts out under braking when the problem is apparent.
I also have an intermittent power loss problem, which after reading about the vacuum problem makes me think. Would loss of vacuum cause intermittent power loss?
Could it be whats causing both issues???

 

[clivvy]

possibly, im not 100% up on vacuum pipes. mine never stalls, its just kinda "jumps" bit through idle randomly. I suspect though, if you were sucking in air where you shouldnt be, then that would certainly cause a problem, liekewise if you werent quite getting the air that you need, that would definatly cause running/stalling problems...

 

[paulp]

air leak

Hi loss of vacuum or an air leak could cause both symptoms because if the pipe is sucking air the fuel mixture will run weak.

run the engine and spray wd 40 over pipes or joins, i appreciate that this is difficult with an intermittent problem.

Has the airfilter sealed properly in the air box or check non return valves that maybe in the brake servo system.

good luck although iam sure you have looked at this already

paulp

 

[clivvy]

thanks Paul, going to have a good look at the weekend...

 

[macabethiel]

tickover glitches etc

If its a turbo diesel there is no engine vacuum as the inlet manifold is under positive pressure that why there is a vacuum pump fitted.

When you press the brake pedal and start to empty the vacuum reservoir that puts a slight load on the engine similar to when your alternator is producing charge this will cause small changes in the engine idle speed that can change as the engine reaches operating temperature.

On a petrol engine there is high vacuum at tickover and pumping the brake pedal will cause small changes to the mixture - hence idle speed fluctuation.

Hope this helps

 

[briggie]

could it be the throttle position sensor ?

 

[clivvy]

If its a turbo diesel there is no engine vacuum as the inlet manifold is under positive pressure that why there is a vacuum pump fitted.

When you press the brake pedal and start to empty the vacuum reservoir that puts a slight load on the engine similar to when your alternator is producing charge this will cause small changes in the engine idle speed that can change as the engine reaches operating temperature.

On a petrol engine there is high vacuum at tickover and pumping the brake pedal will cause small changes to the mixture - hence idle speed fluctuation.

Hope this helps

hmm..didnt know that, sounds interesting...

 

[clivvy]

is it worth putting the Maverick on Nissans diagnostics? can it monitor everything in terms of running etc and pin point a problem? or not?

 

[lacroupade]

is it worth putting the Maverick on Nissans diagnostics? can it monitor everything in terms of running etc and pin point a problem? or not?

since its exactly the same engine, running gear and mechanicals out of the same paella factory (just Ford badges instead of Nissan), then of course it is :thumb2

 

[briggie]

costs nothing to ring them first though , explain your problem and ask if it will diagnose the fault .

 

[lacroupade]

costs nothing to ring them first though , explain your problem and ask if it will diagnose the fault .

Theres no need - its a Nissan Terrano with a plastic Ford badge stuck on the front. There is absolutely no question that Nissan diags will work.....none whatsoever.

 

[clivvy]

I totally understand BUT, my question is do you think it will be worth it? I have never had a car on diagnostics before, so unsure of the sorts of things it checks for? I'd imagine they plug it in, run it, and somehow get feed back from the engine. my point is, will those diagnostics pick up on the odd idle problem, or miss it>? Im worried that putting a car on diagnostics will only tell me what I can find out by reading the MIL light flashes myself./...

 

[macabethiel]

engine idle

Have you read my previous post about my brake booster warning light fault ?

When I checked my vacuum hoses half of them were perished and loosing vacuum its worth checking them.

 

[lacroupade]

I totally understand BUT, my question is do you think it will be worth it? I have never had a car on diagnostics before, so unsure of the sorts of things it checks for? I'd imagine they plug it in, run it, and somehow get feed back from the engine. my point is, will those diagnostics pick up on the odd idle problem, or miss it>? Im worried that putting a car on diagnostics will only tell me what I can find out by reading the MIL light flashes myself./...

well if you can do the reading yourself,no it won't tell you anything extra....all the code descriptions are in the manual.

The sad reality is that many Nissan workshop staff haven't got much of a clue about these trucks....because they are horrendously expensive to have dealer serviced they tend to go to the cheapest garage they can as soon as they are out of warranty (I used to be paying £300-400 every 6000 miles even in warranty!!!!)...which means the workshop staff tend to be more experienced in module replacement, i.e. expensive warranty work involving not a lot of diagnostuc skill a lot of the time.

So yes, they will find codes, but if you can too theres not a lot of benefit apart from having to pay them. Better to give them the codes and see what they make of it....if they are feeling helpful that is...:doh