Hi AllMy friends Scooby (96 classic) seems to hesitate at about 4K revs? not all the time? but just suddenly starts jumping when driving along? on and off? we chnage the engine hoping to cure it? but still doing it? any ideas? we changed coil packs, plugs & leads etc?

 

will it be an ECU based problem or a faulty sensor?

 

When the engine was changed did you use all the old sensors?

 

Lamba stayed the same as did the 1 near the airfilter, i believe everything else came with the new engine? really confused by it?

 

has it been mapped for the new engine?

 

does it need to be? its just another engine from a car of the same standard set up? and it had the exact same problem before the engine was swapped?

 

Check all boost pipework and maybe give the boost solenoid a good clean. Look at the things that havent been changed. Also if possible, swap the ecu to see if that solves the problem (swap like for like wrx - wrx, not sti - wrx etc)

 

cheers mate i'll let him know, do ya think my 1993 wrx type RA ecu will work in his 1996 wrx? if so i could try that once i have mine changed?

 

not sure on the ecu to be honest if that would work (if it has the same amount of connectors to the loom it will work) but I dont know the spec of the ra engine if it has different internals to the 96 wrx (cam profiles etc) so may not be a totally accurate way.

Check the boost pipework though and clean the solenoid (connect the connectors under the steering columm so that you can hear the solenoid clicking away)

 

Where is the boost solenoid located, this could be his problem cause it only does the jumping on full boost?

 

ahh fiar doos, hadn't realised it was the origional engine that was causeing the issue still

 

yeah thats cool mate, its just a joke! bl@@dy thing! cant believe after all that work it still does the kangarooing but its only ever when on booooost!!

 

Cheers Si (JGM) im gonna see if the speedo is the thing thats kicking in the hesitation. before the car speedo was working but since the new engine. it did stop working so i'll have to see if finding the speedo cable and reconnecting that will get the thing working right??? any1 know where the speedo cable is located gearbox side?

 

Ross hope you get it sorted mate

 

yeah Cheers Ian, Si said to try the speedo cable as this will cause hesitation sometimes so i'm gonna give that a go. all good fun aye mate! any1 know where the cable is located gearbox side i.e what side front or back???

 

yep as said on the phone no speedo and it will cut at about 4000rpm

Simon

 

at least you are still smiling

I'd imagine its going to be on the left of the 'box- same side as the turbo...but if I'm worng I'm sure someone will be along to correct me

 

my car still worked fine when my speedo was disconnected, alright the rev counter went nuts and CEL light would flash on and off but drving wise it was fine. I have sti import 1997 dunno if this would make a diffrance

matt

 

cheers guys i'm open to all suggestions i just wanna try and get this sorted need to rip him up in my RA lol fairs fair!! (cant have any excuses)

 

it needs a speedo input else the ecu goes in limp mode and cuts the rpm at 4000rpm..

Simon

 

Cheers Si. I'll have a look on the weekend, hopefully get that sorted. its weird cause it done the hesitation before the engine change when the speedo did work. but after the engine change the speedo obviously wasnt connected correctly. where does the ECU take the speed input reading from? could this be damaged?

 

speedo drive in gearbox via cable to dash.. then electronic pulse from the speedo to the ecu..

if uk it is the same only electronically from gearbox to speedo and then to ecu etc..

Simon

 

Thanks Si, i think i'll check his speedo cable first @ the gearbox then pull the dial cluster out and inspect the cable and wiring from that end. hopefully i can cure the problem. does the speed sensor wire come straight from the back of the speedo? or is it a certain colour whereabouts etc?? (1996 wrx import) cheers

 

I had kangarooing issues (off-boost) - replaced TPS, ICV and added an earthing kit all with no luck. Eventually traced it to water in the main engine loom connectors. They're right under the drain from the blanked off bonnet vents. One drip cover later and no issues since.

 

Thanks mate, as simple as that! i'll defo geive that a check!!!