Start and idle problem 2.8 V6
 

ok first watch this


this only happens at the first start of the day i.e. Cold start.

Every start after this takes ages to start. Cranking and cranking and then it splutters into life and slings a whole lot of unburned fuel out the back. Any ideas?

Re: Start and idle problem 2.8 V6
 

Does the idle after cold start slowly go down as the engine warms up ? It's pretty normal.
not sure what the hot start problem is, could be overfueling thinking it's colder than it is.
I can't see on my mobile what engine it is, if it has a cold start injector , in plug it when the cars warmed up then try and start it. Could be coolant temp sensor. Check codes on ecm will prob tell ya .

Re: Start and idle problem 2.8 V6
 

It's a 2.8 motor. Ok I'll try unplugging the cold start injector. New coolant temp sensor. No codes. Yeah it does slowly come down as it warms up but it's not right. Its stinks of fuel when running and it shouldn't.
I'm gonna buy a new harmonic balancer too and fit that to double check timing is correct.

Re: Start and idle problem 2.8 V6
 

Ok so I've had a good look at it today. Absolutely thrashed it once it was warm, and having checked the timing for the third time, and it runs an awful lot better thanks to that. I don't know what or how but it does idle a lot better.

Now if you turn it off and immediately start it again, it starts fine. IMMEDIATELY. Almost no crank. But leave it 10 minutes and it cranks for around 7 seconds and then splutters into life stinking of fuel. I tried to disconnect the cold start injector but the connection is directly beneath the distributor and I just can't release the clip.

Any advice?!

Re: Start and idle problem 2.8 V6
 

Are your injectors in good shape? Could be failing, could be stuck open with gunk. I wonder if they're slowly leaking fuel into the cylinders while the lines still have pressure in them (fires right back up because not much fuel has had time to leak, after 10 minutes fuel has had time to leak and the engine is flooded.) You can try throwing a fuel pressure gauge on the fuel rail and see if there's any abnormal drops in pressure while sitting.

Re: Start and idle problem 2.8 V6
 

I've been wondering the same thing. When I rebuilt the motor I used a rebuild kit to freshen up the injectors but of course that doesn't mean the fuel isn't leaking past.

The only other thing I can think of is that it has had a custom chip in the ECM. As far as I can remember it didn't do this before I redid the timing on the stock chip.

Re: Start and idle problem 2.8 V6
 

PS any recommendations on a fuel pressure gauge? Bit tricky to find here in the UK for a GM rail.

Re: Start and idle problem 2.8 V6
 

Don't have any recommendations sorry, best I can say is take a screwdriver and hit the schrader right after priming the pump, see how much fuel blows out. Prime it again and wait 10 minutes, see if it's the same amount or less (or if any depending on how bad the leak is). Not too scientific but next to tearing out the fuel rail and testing the injectors one by one it'll get you somewhere :p

Re: Start and idle problem 2.8 V6
 

check the pages I posted from my manual:

https://www.thirdgen.org/forums/v6/7...arting-up.html