VR Revs Drop in a 'Pattern'
Hi Guys, I got my old VR 93, 350,000 on the clock. Duel Fuel. (now my sisters- who drives like a granny)
Most recent issues. power steering pump replaced(just got old), and intake manifold gasket done(by me)
Oil or brown crud minute levels of it can be found in the radiator and the cap. I did a recent Flush, ehh not much came out, the heater stopped working, but after the flush, works now.(musta gotten clogged)
The problem is this and I don't know what really to check. I recently changed with the right NGK plugs and leads. maybe 5-10 thou ago, but there was no issues then and its only recently started.
When you first start the car its a hard start need to pump the pedal to get the gas inside the chamber and she starts up. starts up first go on petrol, so i guess its just a 'gas' thing.
After she warms up, the revs drop, and go up, drop and go up, drop and go up. but there is a about 2 seconds between each 'lowering of revs' and coming back up. sometimes as the revs drop it looses it completely, engine off
the problem is it stalls, recently driving around the corner at low speed and it cut out, quite dangerous if your turning at slow speed onto a high speed road and the engine cuts out
Whats the process of diagnosis? Could it be a piston not working? or something along the lines of ignition? Any vacuum leads undone maybe? I just havent experienced this before.
Thanking you.
What you are describing is pretty much indicative of a failing IAC, or an IAC that is just getting "stuck". It's kind of a pain in the arse to "test" it, since you can't really take it out and clean it (Well, you can.. But if you take it out, you might as well just replace it anyway).
You can try cleaning your throttle body with some cleaner that you can pick up relatively cheaply from your local auto store if you really want to. Mine was recently doing this and I took the cheaper way of the two (Cleaning it) and it worked for about 2 weeks before it started again. I usually just tap my accelerator every now and again when I feel the RPM's slipping.
Good luck.
Hey dude, thanks for the reply.
I started it up before Was going to rip off the throttle body. But maybe during the day.
Its also making a scraping knocking sound as the engine is running. I put a long screw driver onto each of the pulleys or close to a non moving part (BEING CAREFUL NOT TO GET YOUR HEAD, HAIR, TIE, SHIRT OR ANYTHING Stuck in the pulley as you do this... actually please dont do this) and used it like a stethoscope to dry and listen to knocking or vibrations.(works most the time!)
Most knocking was felt from the power steering pump reservoir on top a hell of a alot of vibration, but the sound feels like its from the 'centre' if that makes sense. like it could be the water pump aswell, could failing bearings, or even a failing pulley/pump cause the rough 'cylcing idle? or would the engine be easily able to pull it around..
hope i make sense.
The bearings went in my water pump a little while ago and it didn't do anything with the idle, just made a lot of racket. But I am sure if you have some sort of "wobble" in any of your pulleys (Especially the harmonic balancer) would drop your idle, but by what amount is debatable.Originally Posted by Go_Slow
Hey dude, thanks for the reply.
I started it up before Was going to rip off the throttle body. But maybe during the day.
Its also making a scraping knocking sound as the engine is running. I put a long screw driver onto each of the pulleys or close to a non moving part (BEING CAREFUL NOT TO GET YOUR HEAD, HAIR, TIE, SHIRT OR ANYTHING Stuck in the pulley as you do this... actually please dont do this) and used it like a stethoscope to dry and listen to knocking or vibrations.(works most the time!
Most knocking was felt from the power steering pump reservoir on top a hell of a alot of vibration, but the sound feels like its from the 'centre' if that makes sense. like it could be the water pump aswell, could failing bearings, or even a failing pulley/pump cause the rough 'cylcing idle? or would the engine be easily able to pull it around..
hope i make sense.
What you need to do is take off your belt and spin each of the pulleys by hand (obviously without the engine running :P, no super screwdriver protection here :P) to see if you can feel any sort of resistance and/or dryness. Usually if they "feel" or sound dry, then the bearings are gone and need to be replaced.
No Luck cleaned IAC throttle body. any other ideas? no engine management light comes on
( .Y. )
It sounds like a vac leak.. Get a can of "Aero start" or "start ya bastard" and when the car is at idle spray the vac hoses and if the rev's pic up then you have found your leaky line.
The stuff is VERY explosive so be careful and do it when the engine is cold.
But also I have seen this issue when people put e10 in their tanks and it starts to remove the years of sludge and grime from the tank and fuel lines and then clogs the fuel filter....
You say that its fine when its cols but not when its warm, so when its cold disconnect the air flow meter and see what it does and do it once its warm also.
Just see what that does and get back to me...
Funny you bought this thread up my vr is doing exactally the same thing..is alot worse when its hot..
could be anything to do with fuel?
fuel pump...or injectors?
because you need to pump the accelerator when cranking it...
Also when you say spray the vac hoses...do you mean down the hose or just on it or what??\
and these are the hoses going to the throttle body right?
Posting Permissions
LinkBack URL
About LinkBacks
Reply With Quote