Jordan Radesi

Hey guys really need some help. When trying to start my car I don't thi the injectors a spraying fuel into the cylinders. I did all the test for the fuel system and only thing I could find is when I check voltage on the injector plug it has voltage going to it all the time when I think it only should have power going to it when it sprays? What u guys think it is or what else can I check. It's getting spark and timing is good so I'm stumped. Thanks!

Injuneer

What year is your car? Not all years of the LT1 engine are the same. Add a "Signature" with basic info about your car - year, model, engine, trans and any major mods. That helps us help you.

You should have 12V power to the pink wire in each injector harness connector at all times when the key is on. The PCM supplies a ground to fire the injector. If either the injector, the power supply to the pink wires or the PCM ground circuit is faulty, it will set a code for the injectors in the PCM. I'd tell you the code, but don't know the year, so I can't.

Have you scanned it for codes? Have you checked the fuel pressure? For example, if there is a problem with the low resolution pulse signal from the optical cam position sensor in the Optispark distributor, the PCM will set a code for loss of the signal and shut down the fuel system, but does not turn on the SES light for that code.

Jordan Radesi

It's a 95 six speed lt 1. Check engine light isn't on but never had the dash apart so I don't even know if there is a bulb in there in the first place. I know I have fuel going to the fuel rail but not sure what pressure it has.

RamAir95TA

Whether the bulb is in there or not it will still tell you if there are any codes present. Not all codes set the SES light either, so it's worthwhile to have it scanned.

You'll also need to pick up a fuel pressure test gauge. They are fairly inexpensive (<$40) and are an invaluable tool for any LT1 owner.

Jordan Radesi

Ok the light is on and tried to get a code from it but all the light does is stay on and doesn't flash to give me codes. Must not have the paper clip in right?

Injuneer

You said:
...... but you didn't check the fuel pressure? What "test" did you actually do?

Jordan Radesi

I checked and made sure I had fuel in the fuel rail by pressing down on the valve where u put the guage. Fuel sprayed out very good so I would think the pressure is good

Injuneer

So you were able to determine from that test that the fuel pressure was meeting the minimum requirement of 41psi?

If you don't want to check the pressure, don't bother. Maybe you'll figure it out without testing it.

Jordan Radesi

So your saying even if I have fuel in the rail if it's not the right pressure the injectors won't spray at all. Not trying to do it the easy way just won't be able to get a guage right away.

Jordan Radesi

Just need to know what would make the injectors not to spray. Thanks for the help guys

MyShibbyZ28

What Injuneer is saying is you need to do this the right way. There is no "easy" or "quick" way.

You are stuck on this whole notion that the injectors are not opening. I highly doubt that, and the injectors will still open if there is absolutely no fuel in the rail. I have never heard of an injector (and what you are hinting at, all 8 of them) not opening.

Also you cannot jump your 95 with a paper clip to flash the codes on the SES light. The last year you could do that I believe was 93. On 94 and 95 years you need an OBD1 scanner, or a cable and use FreeScan.

Lastly, you have not said once what the actual symptom was of your starting issues. All you said is during starting you think the injectors are not getting fuel, this explains nothing.

What exactly is the car doing/not doing, and what are the main problems?

Jordan Radesi

After taking the motor apart to install new timing chain it won't start. I have good compression and spark from the coil and at the spark plugs. Pretty sure the timing is on after doing it plenty of times. So my problem I have is no fuel is going into the cylinders.

Injuneer

No, I didn't say that.

Since it appears you are more intent on engaging in a debate over semantics than you are in fixing you car, I'll bow out.

Good luck.

Jordan Radesi

I'm getting a pressure guage tomorrow. Didn't mean to **** you off man jeez. Just new to this forum thing so it's kinda hard to explain what the car is doing. Sorry again

blown94

Id like to know if he figured the compression was good in the same manner he guessed the fuel pressure was good?

Listen, if u dont have a noid light set, go buy a cheap test light and clamp a paperclip to one end an insert it into an injector plug and prod the other terminal and have someone crank the damn car. If it flashes then you have injector pulse. Even if u do have pulse, im willing to bet you did not insert the opti correctly and the pin is the proper place, thereby making your spark timing incorrect and causing your no start.

The cam dowel drives the optispark and needs to be in the correct spot and ive heard of people not lining it up properly before.