hard start after replacing fuel injectors

[straight6pwr]

hey guys, just installed rebuilt injectors into my m20 (im chasing the hesitation bug) and since reassembling have been having a really hard time starting the car when its cold. it takes about 5 secs or so of cranking to start the car, then it runs really choppy for a few seconds. they only things that came off the car were the valve cover, the crank case vent hose, and the injectors/fuel rail. i went back and replaced the crank case vent hose/clamps thinking it may have split during the tussle, but that didnt solve anything. the valve cover got a new gasket, so that isnt it. what had to have happened to cause such an immediate change? could the o rings on the injectors be letting air past? bad injectors? i checked with the guy who sold me them, and they were working fine on his car just before i bought them. how big of an air leak would have to be created to cause bad start issues?

[Sagaris]

My first thought is that there is a small fuel leak that would drop your fuel pressure enough to only affect the initial startup but it would seem like any sort of fuel leak would be pretty obvious.

When I installed my injectors they were really loud for the first few miles and I was wondering if the solenoids were sticking since the injectors hadnt been used in a while so I have been using the Lucas upper cylinder lubricant in the fuel and it has quieted things down a bit. It's a bit of a stretch but perhaps your injectors are sticking open/closed until theres enough fuel to lubricate them enough to do so freely.


oh, and if they are stock 14# injectors I have my old ones if you want to try another set, I also have some new o-rings as well.

[jlevie]

That (and the hesitation) would most easily be explained by intake leaks. A smoke test of the intake will quickly tell if there are any intake leaks and where they are.

[straight6pwr]

It's a bit of a stretch but perhaps your injectors are sticking open/closed until theres enough fuel to lubricate them enough to do so freely.

oh, and if they are stock 14# injectors I have my old ones if you want to try another set, I also have some new o-rings as well.

i may hit you up for those o-rings, thanks.

That (and the hesitation) would most easily be explained by intake leaks. A smoke test of the intake will quickly tell if there are any intake leaks and where they are.

thanks, this is what i suspected. i did somemore searching/fiddling around the TB area again today and from disconnecting/tightening things and putting it back together, there was yet another change in behavior. smoke test it will be.