Turbo first starts - stumbles when adding throttle

[rossonza]

So i got my mr2 started for the first time the other day, was a bit lumpy but last night we got the timing light out and got it timed, it idles happily doesnt miss at all etc.

I am however having a problem where im applying throttle and its stumbling trying to cut out. if i hold the throttle at a fixed position it eventually tries to rev out and doesn't stumble.

its had all new dizzy/rotor/leads fitted. timings done. fresh coolant put in.

note: airbox was just loose sat in the engine bay.

any ideas where im going wrong? or likely suspects? i've just ordered new plugs as well.

forgot to add, this is during cold start. i havnt let it warm up yet so ill be trying that later.

Thanks
Ross.

[almeida1234]

How old is the fuel in there?
Clean out ur throttle body. Also check your coil and igniter.
Coil tend to crack and absorb water over time.
Other things to check is are boost leaks fuel pump etc.

[rossonza]

Clean out ur throttle body. Also check your coil and igniter.
Coil tend to crack and absorb water over time.

ok will do, coil/igniter should it be obvious its failed? is there a way to test it. both havnt been used for 8 ish years.

[rossonza]

Im sure this won't be helping;

[almeida1234]

Check the metal bracket that's connect the coil to the firewall.
Earthing is an issue too.

[rossonza]

changed my plugs and re-fitted airbox correctly and it seems to idle no issue. adjusted TPS to get the throttle response normal. However its still stumbling. so need to check the coil etc.

i forgot to ask, i disconnected my AC Idle up valve. so ive got one vac line going from my throttle body into the other idle controller (presume standard throttle idle control).

as the cars idling without issue am i safe to presume theres no issues on that side with me removing the AC idle up valve?

[pbmr2]

Have you checked for error codes? If not then do.

Error codes


coil test


temp sensor


All this stuff is in the manual and has test procedures for various issues, including missfire/stumbling on part throttle. Get a copy of the BGB and just read the process, then follow it.

You can't really test the igniter.
At least you know it's getting more than enough fuel.. which tends to suggest it knows there is a sensor fault or whacky reading from one so it's dumping in loads of fuel to be on the safe side.

[rossonza]

you know what? i actually havnt, i presumed id get a warning on the dash if a code had been generated. Thanks so much for your post, I'll give it a try tonight

[timmomr2]

Sorry to hijack but I have something similar dropped the car of with my mate who has his own garage and knows the car well so I'm hoping he finds it.

My car starts up fine but then chooses to dump a ton of fuel into the engine making it run like crap. It will only rev to 3600 rpm and sounds like it's hitting anti lag (which it doesn't have) then it cuts out and won't start again for a while. Is this similar to what you are getting?

[mr2garageswindon]

Have you checked the ECU for blown caps?
Worth a look...

[markstevieandmads]

and check coil for cracks

[timmomr2]

I haven't but have just passed that message on seems a common theme.

[rossonza]

Sorry to hijack but I have something similar dropped the car of with my mate who has his own garage and knows the car well so I'm hoping he finds it.

My car starts up fine but then chooses to dump a ton of fuel into the engine making it run like crap. It will only rev to 3600 rpm and sounds like it's hitting anti lag (which it doesn't have) then it cuts out and won't start again for a while. Is this similar to what you are getting?

no unfortunately doesn't sound the same as what im experiencing. sorry

[rossonza]

Have you checked the ECU for blown caps?
Worth a look...

its on my list now thanks

[rossonza]

and check coil for cracks

went to remove it last night, didnt realise how awkward it would be to remove it. fusebox is in the way and i cant get my socket set on the bolts...any tips?

[SonicSW20]

Either feel around blind with a 10mm socket + extensions, or unbolt the fuse box and move it aside first.

[rossonza]

Either feel around blind with a 10mm socket + extensions, or unbolt the fuse box and move it aside first.

i couldnt get my socket onto the bolt was my main issue, the coil housing was in the way by a few mm. I think ill undo the fusebox cheers dude.

also i was attacking it whilst the cars up on axle stands whilst i was balancing on some bricks to get in from above... probably didnt help

[SonicSW20]

Did you take the plastic cover off first?

[rossonza]

Did you take the plastic cover off first?

hold on....theres a plastic cover?

[SonicSW20]

Yep: http://japan-parts.eu/toyota/jp/1994/mr ... r/2#89279A

Can see it at the bottom of this (it's installed the other way up in the car:



With the wires unplugged you can just slide it off. Only adds a mm or so of width, but that might be enough that you can't quite get a socket onto it straight.