I have just had t28 turbos fitted, i went to pick the car up and on idle it sounds and runs really really lumpy! like an american V8 muscle car! ive checked plugs and coils, looked for breathers etc, any other ideas? when its going along it goes quite well bet still not quite right and if i rev it gently on the spot its all burbbly, also used half a tank of petrol to 50 miles!!! smells like pure petrol out of the exhaust, its had other mods but fitted before turbos and no problems before, front mount, dump valves etc, nothing major. any help :confused:

Sounds like its definitely misfiring. And going on the 'pure petrol' exhaust smell, that rules out injector problems (well, unless you have one stuck open) so must be either the PTU, a coilpack or a plug, or the wiring to one of these. What have you done to check them?

 

What other mods have you had done too, you can't just stick t28's on and hope for the best.

failing any of Clarkey's suggestions, check the air filter isnt wet.

yeah its defo a missfire but can work out what, ive checked plugs and leads, got a front mount hks induction and dump valves, and the plan was then to fit my injectors and fit my link ecu and set up the next day, but couldnt due to the missfire, oh and the air filters are bone dry,

The excess fuel consumption could be the Fuel pressure regulator not returning excess fuel back to the tank or fuel pressure damper not absorbing fuel pressure changes when the injectors open and close.

 

I've just read your post again. You have just had T28's fitted, and you say your fitting injectors? What size injectors? Whats been done to the ECU, have you had it chipped and re-mapped? If you have had it re-mapped for bigger injectors and your running stock injectors you might be maxin out the stock injectors, or your over fueling? Have you had a fuel cut defender fitted too?

A simple thing to over look, are the coil pack connectors on in the right fireing order? 1 and 2 can get mixed up, ive done that myself :smash:

if youve had tubbs fitted then youve had the engine out , if you have had the engine out youve had the injectors / coil packs un plugged ...........check the connectors are back on the right injector .........it sounds like a cross over somewhere

 

steve

cheers for your help guys, i will check a couple more things and post back, firing order sounds interesting ill check that out, in reply to CarlZ, the turbos where fitted as phase one of my plan, and the day after i got it back the injectors and a LINK ECU from new zealand where to be fitted and mapped/set up, have i done things the wrong way round? and anything else i should be doing?

As said, you have a misfiring cylinder, which is going to be becuase all the wiring and coilpacks and been disconnected and disturbed when engine was out.

 

Pull each coilpack of 1 at a time....if the engine note does not change then thats your misfiring cylinder. Check plugs are pushed on correctly, wiggle the wiring....unfortunatly the 300zx wiring tends to get very brittle with age from all the engine bay heat.

cheers for your help guys, i will check a couple more things and post back, firing order sounds interesting ill check that out, in reply to CarlZ, the turbos where fitted as phase one of my plan, and the day after i got it back the injectors and a LINK ECU from new zealand where to be fitted and mapped/set up, have i done things the wrong way round? and anything else i should be doing?

 

right so all thats been fitted so far is the tubs? You are still running stock chip with stock injectors then, so the fuel mapping is fine. You proberbly not getting any more boost than stock at the moment as the stock chip is still only boosting to its perimeters. It dosnt matter what way round you do the mods in your case as you where going to change to an uprated ECU an injectors strait away, and thats the tip of the iceberg. Im just wondering though what psi you hope to run at, as im guessing your still be running stock engine internals? If you just want to run up to 1 bar then you didnt need to change the tubs and injectors, although they would be at their max and not really recommended to run old stock tubs and injectors that high. If your wanting to run higher psi and much more bhp your going to be starting to look at engine internals. Also you going to want bigger intercoolers, an electronic boost controller and a bigger rad to cool the engine better. Bigger brakes to stop the bugger too, highly recommended, and thats without suspension (assuming you havnt already done these?) :D

thanks for your help guys but the cars a dead issue now, i did a couple more checks this evening, fired it up left it on idle for about 40seconds and the engine blew up, now sounds like a bag of bolts going round a washing machine, !gutted!, god knows what the mechanic did when he fitted the turbos but is claiming it was idling fine when i picked it up and now claims he had nothing to do with it, ARSE HOLE! anybody know if i have a leg to stand on? can i insist he rebuilds it or puts a new lump in free of charge? if not i cant afford to do it all again so the car will be broken and lots of parts for sale,

Thats bad luck bud, but hold on first lets see what we can do. From where is it rattling from, top, bottom of the engine? This proberbly explains your running issue might of dropped a valve or lifter if its coming from the top end. What else did this Mechanic do?

all the machanic did was take the engine out and fit the turbos, but it was lumpy from when i picked it up, sounds like something is rattling in the top of the engine, bottom end sounds fine,

Possible oil feed problem apon refitting, if so it would be down to the Mechanics/Garages fault....however you need an independent inspecton to confirm exactly what is wrong and how it happened.