Momentary shuddering throttle at low revs... Fuel issue??

pjeadie · Post by **pjeadie** » Wed Jul 16, 2008 9:23 am

Hi guys,

Went to garage on Friday to fill car, which had just popped up with refill. Went back after paying and car wouldnt start - sounded like it was dying due to a lack of fuel... managed to get it started by getting a mate to turn the ignition as I manually opened the throttle switch next to the engine..

It has been starting fine since, but has picked up a shuddering around 2500-3000 rpm. It can be quite severe, and feels like there is a sudden stuttering in the power out put.

It tends not to happen when the engine is colder ie first few miles of journey. The exhaust (im told) was quite sooty when I started it last night having not driven it for 24hrs.

This is obviously a fuel issue, but Im not sure exactly what. Is there a manual way to alter the air to fuel ratio?

Any help / advice would be greatly appreciated.

Cheers guys,
James

Post by **Shug** » Wed Jul 16, 2008 9:28 am

What car is it? S1 S2, Toyota engine, Rover engine?

pjeadie · Post by **pjeadie** » Wed Jul 16, 2008 9:30 am

Sorry, its a s2 Honda engine...51 plate.

Post by **Shug** » Wed Jul 16, 2008 9:48 am

Hmmm,

Don't suppose you know which install it is? Link-up or Sinclaires, or something else?

Might be duff sensor, might be pressure regulator set wrong (if it's adjustable) but I'm not really up on the Honda installs, so will shut up now and leave it to someone who knows better

Rich H · Post by **Rich H** » Wed Jul 16, 2008 11:05 am

Are you sure its a Honda? Fly by wire throttle sounds like a Yota...

I would be looking at the ignition to be honest. But I know cock all about honda's/yota's too.

pjeadie · Post by **pjeadie** » Wed Jul 16, 2008 11:18 am

Sorry, heads not on. Its a Rover engine. Was talking about a mates Rover at the time...

Post by **Shug** » Wed Jul 16, 2008 11:21 am

Ah so - no fly by wire either - red herring there (wondering why you were in the engine bay blipping)

Yup - remove and clean up the leads, take out the plugs and see if any one is sootier than the others. I'm with Rich - sounds ignition-y.

pjeadie · Post by **pjeadie** » Thu Jul 17, 2008 8:38 am

Cheers for the response guys. Unfortunately it happened again last night when I filled the car. Just kept dying after kicking in for a spilt second. Had to do the same as last time and push the small throttle level on the engine to get it started. Might give Ali through in Dalkeith a call and see if he knows.

Will clean leads / plugs this weekend and see if that helps....

Post by **Shug** » Thu Jul 17, 2008 8:56 am

pjeadie wrote:Cheers for the response guys. Unfortunately it happened again last night when I filled the car. Just kept dying after kicking in for a spilt second. Had to do the same as last time and push the small throttle level on the engine to get it started. Might give Ali through in Dalkeith a call and see if he knows.

Will clean leads / plugs this weekend and see if that helps....

Pushing the pedal will do exactly the same thing mate. The TPS is on the throttle body, so it's not reading closed throttle, even if the pedal is up.

pjeadie · Post by **pjeadie** » Thu Jul 17, 2008 9:34 am

Next time it happens (if I dont get it sorted before hand) I'll try it again, but I did start by pushing the pedal a few times before I resorted to the back..

Rich H · Post by **Rich H** » Thu Jul 17, 2008 9:51 am

Sounds odd. The throttle pedal #Should# be conected directly to the throttle body. Is there any slack in the cable?

Sounds like a couple of problems, starting will probably be IACV related the shudder sounds like spark problems.

Clean the IACV and throttle body out for good measure with carb cleaner and reset the MEMS. (Door open, ignition on, throttle open 5 times or more, ignition off, then go for start, should start and run like a POS but will recover quickly and get better, just leave it to do its thing)

Clean plugs but not until you have compared them to each other to ensure you don't have a problem on one cylinder.

Rich

Post by **Shug** » Thu Jul 17, 2008 9:58 am

Just to add - when you do the MEMS reset - don't use throttle to start it, or you'll forever have to (until you re-set again)...

mac · Post by **mac** » Thu Jul 17, 2008 10:00 am

S2 Rich, doesn't have a MEM's and doesn't accept a reset in the conventional way (I think it learns setting's more)

I would test the TPS - get the car running and unplug it - it should start to faulter and die, if it doesn't then it's not working.

Mac

Rich H · Post by **Rich H** » Thu Jul 17, 2008 11:59 am

Oh, ok.
I thought that you reset its learning in the same way??

I'd still lookk at the IACV though.

mac · Post by **mac** » Thu Jul 17, 2008 12:04 pm

Apparently it's always learning (or so I've been told) - I have been able to force a reset - but that involved removing the battery and the ECU - not something I would recommend as you can kill the ECU if you don't put the protective shroud back on properly (been there, done that)

Scottish Elises

Momentary shuddering throttle at low revs... Fuel issue??

Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??

Re: Momentary shuddering throttle at low revs... Fuel issue??