Help!

My 93 Z28 has a starting problem. It takes a long time to start, and when it finally does start.. the exhaust is really rich.. and then it leans out. I was thinking that i have leaking injectors that are flooding things while the cars off... Any opinions on this one?

 

Yeah that's a good reason. Have you checked the oil?

 

sounds like a definate possibility, you can remove the 4 bolts holding the fuel rair down, lift the rail(with injectors still attached) and key the key to n, then see if there are any dripping.spraying

 

Hey guys..

The oil didnt smell like fuel -- if thats the reason why you wanted me to check the oil. ???

Is there a fix for leaky injectors.. or should i just buy a new set? If i replace them.. is there a recommended vendor for stock injectors?

 

You can have them sonically cleaned and flow matched. You can also have them cleaned on the rail but that is more for a blockage problem than it is for a leaking problem. Or you can replace them. Stock is fine, anything but Accel.

 

So if i have the injectors clean and flowed will that fix the leaking fuel problem?

I mean right now the car sounds very aggressive.. its just hard to start.

 

If the injectors are the cause, yes. They need to be investigated first. You could have another problem.

 

I read somewhere on here about using a pressure guage to tell if the injectors are leaking... is that a good way to test? I mean the car has 239K on it.. i am sure something about to let go lol.

 

First things first: 239k MILES?! WOW! I have 182k, but holy ***** man.

Second: If you want to check them with a pressure gauge just attach it to the valve in the back (which I found it's easier said than done, gas sprayed everywhere on me), and do not start the car, just prime it to the "on" position. The pressure should go up to around 40-45. Then watch it, it should hold the pressure for a good time. Mine held it above 35 for a couple hours I believe. If the injectors are leaking it will obviously go down fairly fast.

Another cause of the hard starting might be the fuel pressure regulator. If that is bad then it might also cause the pressure to drop faster then it should. That's what happened to me. I thought I had bad injectors, but my FPR was just letting the gas go back to the tank.

Smell the vacuum line for gas, should be dry. If it smells like gas or is wet, then that's broken. Vacuum line is the small black hose coming out of the FPR pointing towards the passenger side (incase you didn't know).

ShibbyZ

 

On some very rare occasions my car will start up but sound like its only running on four cylinders, giving it throttle only makes the engine shake about and it does'nt feel good at all. Then after 30 seconds or so it suddenly clears and runs fine.

My oil did smell of gas, I then had a full service, including oil change and new filter. Now my oil smells of gas again.

Does this sound like a leaky injector? As I said above the bad startup only happens a few times a year.

If I did lift the fuel rails/injectors to check would I need to replace the o-rings or am I likely to break anything doing this?

 

yes, or bad regulator

 

Is there a recommended regulator for a stock motor? i do plan to bolt power adders on to the motor until it cries uncle. Should i get the stock unit, or just buy an adjustable one now?

 

Don't buy anything until you test it. For the regulator, simply apply a vacuum to it and see if it holds. If your problem where coming from the regulator, it would not hold vacuum.

One other point, if your flooding for what ever reason, you should be seeing real bad fuel milage. Is that the case?

 

The way i stated is easier for testing if the regulator went bad. If it smells like gas or is wet then go buy a new one. NAPA sells an adjustable one and a standard one for the same price of $80. And if it makes a difference, buy the once from the 96-97 years, they are cheaper but have the exact same function, just different part numbers.

But yes, test stuff first before you go out and buy what you do not need.

ShibbyZ

EDIT: I just noticed you have a 93. I cannot remember if 93's had regulators or not, check to make sure i am right or wrong. I could be just giving you a ton of false information if you do not even have one. If you do not have one, it is definitely the injectors.

 

it does, same location