Cold car hard to start,what's the problem?

nzsafe007, Sep 29, 3:25am
1997 Nissan avenir 1.8 auto,after gearbox changed in one garage,cannot start and mechanic spay some gas behind air filter,then start.
now when engine cold,must spay or start after 3-4 ignite. But if engine warm,then start first ignite.
Not electric system problem.but do not know why.anyone can help?tks

kazbanz, Sep 29, 3:33am
take back to garage that did the job.

franc123, Sep 29, 7:50am
What happens if accelerator held partly open when cold starting, does it start straight away then?

nzsafe007, Sep 29, 2:05pm
Yes,that's the result,now I spay before start because they cannot find how to solve it also.

nzsafe007, Sep 29, 2:06pm
now must press the accelerator when ignite to start. even the mechanic did not tell the reason after I left the car for some time.

andy61, Sep 29, 2:38pm
Do you need to spay or spray? Spay is what you do to you pets to stop them making babies! its hard to visualise you spaying a car. I would b changing your mechanic to a better one, could be a number of things from a faulty air flow meter to a fault preventing the ` cold start choke` coming on. It almost does sound like an electrical issue.

franc123, Sep 29, 6:48pm
Cold start choke lol, umm no. Assuming SR18DE here and nothing associated with the intake pipework has been left loose or disconnected following the work I would be looking for an idle control valve that has failed in the closed position, or an issue with the circuit. Seen this more than once on older Primeras with same engine.

intrade, Sep 29, 6:55pm
i would check if the coolant temp sender is actuarl hooked up and working because if its not it wil use a sunstituted value of warm engine = no coldstart injection takes place as the ecu thinks its already warm.
that is just a guess and what i be checking as first thing with nissan consult 1 adapter and capapble software to read out that information .

intrade, Sep 29, 7:14pm
here is what i think. get consult 1 nissan diagnostic monitor the coldstart advance and the coolant temp sender pids, unplug both coolant temp senders there is 2 sensors one for the dash cluster and 1 for engine managment.
default value unplugged on a nissan should be -88° celcius ,
Now if it dont changes the values when you unplug it, Then somone most likely crushed the wires and shortened the engine coolant temp sender so the engine managmant thinks its hot due to the short to ground on coolant temp sender and you know who done it the ones who worked on your gearbox.
So you could also just get a 300$ flashlight out and look for crushed wires .

intrade, Apr 16, 6:12am
also look for loose earth wires , older cars have huge tollerences to missing earth wires unlike new cars a new nissan would not even open up the trottle body if 1 of the 21+ can bus items has been shortened or has high reseistance.