still have an intermittent bad starting problem :(

[dac69er]

have replaced everything, sensors, injectors, fuel pump, ecu etc etc. have also rebuilt the engine and the car still does it!!!

randomly it will just be a bit spluttery/hesitant from start up. his only lasts for a second or 2 and then sorts itself out. doesnt matter if its hot or cold.

any ideas? only thing i can think of is that there is an issue with the throttle body???

 

[malcolmgt]

tried looking at the dizzy, i had similar issues with my GT ages ago. would start up, then live for a little bit and died. then just kept almost sounding lumpy. turned out to be the dizzy, replaced it and it was fine.

 

[dac69er]

tried looking at the dizzy, i had similar issues with my GT ages ago. would start up, then live for a little bit and died. then just kept almost sounding lumpy. turned out to be the dizzy, replaced it and it was fine.

when i say i have changed everything, i meant everything replaced the dizzy, coilpack and ignitor. also have a new cap and rotor arm now the engine is rebuilt and it still does it.

 

[Rev]

On cold start the single wire o2 sensor is not up to temp so the car starts in open loop initially. I have been adjusting my safc2 to test this and find if I lean out the open loop map at idle the car dies for 2 seconds after start till the sensor kicks in and it goes to closed loop . If I richen the map the engine doesn't do it or not so much.
It doesn,t drop revs on warm/hot start when the 02 is up to temperature so I am thinking you may have a combination of issues.

What injectors do you have?

 

[dac69er]

car is standard apart from a jam ecu, decat and stainless exhaust.

none of my other 2 GTs do it and this one only does it intermittently. it makes no difference if the car has been for a run or not. outside temperature makes no difference either.

 

[Rev]

Standard is good. The jam ecu is reported here as running much leaner so I guess its open loop is a bit leaner than stock.
Thats seems likely to be related.

One thing to check would be inside the little tube on the throttle body that goes to the map sensor this tube gets crap from the inside which can effect the vaccum slightly.

 

[dac69er]

tried a standard ecu, no change. replaced the map sensor and the pipe + little filter. also tried it with no filter, no difference.

just wondered if anyone had any other ideas other than the throttle body as i have literally replaced everything

 

[jayc-glanza17]

duncan, i have something similar, as mine is left weeks, or few days before fired up..
when i go to start it, it runs rough as dogs for 5 seconds, if i blip throttle it ceases and revs high, but steady..
if i dont blip it, it runs rough for 5 seconds then goes to normal cold idle..

i have just taken my throttle body off and cleaned it, and i will re fit saturday, so can report back for you dude..

 

[dac69er]

duncan, i have something similar, as mine is left weeks, or few days before fired up..
when i go to start it, it runs rough as dogs for 5 seconds, if i blip throttle it ceases and revs high, but steady..
if i dont blip it, it runs rough for 5 seconds then goes to normal cold idle..

i have just taken my throttle body off and cleaned it, and i will re fit saturday, so can report back for you dude..

sounds like mine. i gave the throttle body a clean whilst the manifold was off, but didnt separate it to really clean it.

let me know how you get on, as that is the only part i havnt replaced that i would think it could be!

 

[ben10]

sounds like a good plan. clean the throttle body out, re calibrate the throttle positioning sensor and clean out the idle solenoid.

 

[jayc-glanza17]

duncan, i re fitted my throttle body, and hey presto its far better..
now i re calibrated the TPS, and cleaned TB all out and re did all coolant and vaccum pipes..
seems atm the have cured the problem..

 

[ben10]

;D glad to hear

 

[dac69er]

duncan, i re fitted my throttle body, and hey presto its far better..
now i re calibrated the TPS, and cleaned TB all out and re did all coolant and vaccum pipes..
seems atm the have cured the problem..

mine is very intermittent though. sometimes goes for a month or so without doing it. hopefully got a replacement tb on the way so will clean that up and go from there

 

[Paul_JJ]

Well I had similar problem! Turned out that the Alternator belt wasn't tight enough and the earth was bad, so I put a separate cable from the Earth on the battery to the Gearbox directly - just like Tim from the TB Developments advised - and hey presto it's perfect afterwards and never missed a bit!!!

What kind of alarm have you got if any? I have a feeling that it could be something to do with the bad earth and most likely you get it from the aftermarket alarm...

 

[dac69er]

alarm has been rewired by me as it wasnt installed properly. wiring loom has been out. have also added lots of extra grounding points as that was one of my initial thoughts. replaced the alternator too. still does it.

 

[Paul_JJ]

A starter motor?

 

[dac69er]

Yup. Tried that too!

 

[goldenvtr]

may of alrady been suggested but have you tried replacing idle control valve - might be sticking?

 

[dac69er]

may of alrady been suggested but have you tried replacing idle control valve - might be sticking?

already done, twice. last one i fitted was a spot on one i got from dave burwash was one of the first things i have tried.

 

[Paul_JJ]

My personal opinion that it might have something to do with the aux belts or the cambelt! What cambelt have you got? is it the oem one or the aftermarket?