hi all, i need some advice please...

i have a 96 sti ra, standard apart from a straight through exhaust and a dump valve. all has been well since i bought it, but recently its started jolting and stuttering when i apply full throttle quickly. you can kinda drive around it if you apply throttle more gently, but if you floor it, its worrying me whats goin on with it.

until recently its always started first time, but now when i start it up, it takes two goes on the ignition generally to get it started, but once started it idles fine.
BUT once you engage gear, even after a few minutes, and go to drive off, the engine sounds like its starting to die, getting slower in revs and struggling. take your foot off the gas, the engine then kinda sorts itself out, revs rise again, and you can drive off. really weird.

once the car has been driven for a while, it restarts at any time fine, but still jerky on WOT.

this is something that has got worse recently.

any ideas please, want to get it sorted asap, many thanks for any help

 

MAF?
CTS?

 

Plugs/leads?

 

If it's the maf, is it an expensive fix? I've been thinking if a simtek remap , would I still need a maf? And what's the Cts please? Many thanks for the help

 

* Brand new OEM MAF's for MY93-96 (green label ones) are c.£260-270!, IIRC. Could upgrade to a orange label STi 3/4 one or Z32 one and get it rewired/rescaled. Will allow airflow for around 460+ bhp. Can get alleged brand new Z32 ones off eBay for £80.

* Simtek is M.A.P.-based. Unplug MAF connector - and/or remove whole MAF tube assembly - prior to remap.

* CTS - coolant temp sensor, about £30 from Import Car Parts. A failed/out of spec. one can effect starting and low speed running, when cold/warming up.

 

Thats great info, thank you .
Is my car still ok to drive carefully till I get it fixed, or should it be avoided? Cheers

 

I had the same problem on my first impreza (94 wrx) and it was the maf. all i did is lifted the cover off the top and saw the solder had cracked so was a bit hit and miss with the connection so i just added a touch more solder and as stated on other posts saved myself about £200 quid, ran sweet after that.

 

If unsure of MAF being okay, then remain off boost/under c.3500rpm until addressed.

Personally, I'd also only drive it if absolutely unavoidable to do so.

 

coilpacks ever been replaced on it?

could be maf indeed.

try original dumpvalve just to eliminate it?