Im getting kind of frustrated here. I have replaced the battery, fuel pump, fuel filter, opti, ICM, and coil. Cleaned the fuel rails, soaked the injectors in injector cleaner overnight, put new gas in the tank (6 or 7 gallons of 93 to clear up some of the old gas). I have verified that I am getting spark on the number 1 plug wire. I am getting around 37#'s of fuel pressure at the rails. What could be keeping this motor from firing? Is it possible that the injectors went bad from sitting for a few years? Im running out of ideas and getting frustrated that I have had this car for so long and it just wont run after all this work I have put into it.

 

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hey man, i,ve got a 94 z28 a4, i went through the same problem, with mine it was the six inch hose on the fuel pump, when you drop the fuel pump in the tank it curves to the shape of the tank, on mine when it did this it put a kink in the tube, it would still let gas through but not enough to make it run, once i figured this out i took the short hose off the old fuel pump and put it on the new one and no kink, fired right up.

 

I can see an restriction in the fuel line some where messing it up, but I have no clue what the psi at the fuel rail should be, that and what color is the spark? that could tell you it it is enuff to light the fuel, a weak spark will not light the fire. By the way is there any fuel leaking anywhere? but with out seeing the car and testing it I am guessing on the answer, so you need the right amount of air to help the right amount of fuel / air mix light. BTW what is the psi on the cylinders? if you do not have compression YOU will not have a fire, all need to be close to fire, usually 100 psi or more pre cylinder to fire. That can tell you if all parts are seating, Good luck bro !

 

Tossing parts at it will just result in frustration on your part.

Time and money is better spent on testing the condition of your engine. Spark, fuel, compression, sensors.

 

your fuel pressure needs to be in the mid to upper 40's with the key in the on position, if the fuel injectors have been sitting for awhile more than likely they are clogged, just soaking them will not be sufficent, fuel sitting in them for more than 60 days can cause them to go bad. also you said that you checked the spark on #1 what color was the spark?

 

go back to the basics; check fuses etc.

 

Spark is yellow. I do have a small leak at the regulator on the fuel rail. My tank hasnt been dropped but thats something I could look into, I never thought about a kink anywhere. I have not looked at cylinder pressure...but I do have compression, I just dont know an exact number. It blows your finger off the spark plug hole with quite a bit of force. The motor was just built, it hasnt even been fired once, so I cant see any reason it wouldnt have enough compression. And how would I go about checking if my injectors are bad?

 

from what i know there is really no safe way to test the injectors at home there are companies out the that can test them for you. they flow test and spray pattern test them. the only thing i know you can do at home is use a noid light to check to see if they are getting a signal to squirt. i went thru a similar problem with my car recently it would just crank would not start, i checked everything 3 or 4 times, i was getting spark, and fuel pressure was 47psi with key on. finally i noticed that the connector that is on the cable to opti was cracked replaced it and it fired right up

 

Is 37lbs too low for it to start? Im just gettin annoyed I dunno what else im supposed to do.

 

at 37psi it should start. have you checked to see what the pressure is while you are cranking, also after cranking pull the intake elbow off and smell for gas, and pull a spark plug and see if it is wet and possibly fouled. if its not fouled and you are getting spark just for ***** and giggles spray some starting fluid into the TB and see if it will start that way

 

did you check the starter by any chance? just an idea if its not a fuel issue

 

Yes it should start provided the correct amount of fuel is being delivered, however keep in mind that there could be an issue there. Like someone said above if there is an impedance somewhere in the lines or pump it could cause a problem. You can have the correct pressure and still not have the correct volume of fuel being delivered.

 

Well like i said in the very first post, fuel pump is brand new as is the filter. Ive heard that starting a new motor on starting fluid can mess up stuff...?

 

Starter was also replaced just as i bought the car...(at the beginning of the summer.)

 

how did you replace the pump without dropping the tank?

 

you cut open the metal in the truck under the carpet and you have the fuel pump right there. really easy to do and saves alot of time

 

what he said ^

 

hey man what was ur car doin befor u changed all that stuff and why did u change all that stuff cause im in teh same boat u are i changed my opti and for the life of me i cant get this bitch to start adn when it dose it sounds like a cam ....and did u check all ur vacum lines i found one of mine chewed up

 

Well the story is I bought the car from a lady who got a divorce from her husband who was a car guy. He had 3 or 4 cars and she got them all in the divorce. This was the last of his cars that she had, she knew nothing about it, just that it was fast (she had no idea how rare it was or anything or theres no way i would have got it at the price i did :-) ). She told me she used to drive it down the road and around the block once a week, but then one day it started acting funny and wouldnt start again so she put it up under the car port and let it sit for years. I grabbed a battery and put it in the car, and it turned over so the motor wasnt locked up, so I figured I couldnt really pass up the car for that price. I picked it up later that night, and took it home to try and start it. We couldnt get it started for anything so out came the motor and the problem was an intake gasket leak that sat on the pistons all those years. Off to a machine shop to be redone and made like new again. New parts installed, all the good stuff. Then we put the motor back in and it just wont start. Thats why I did all that cruzin94. Sorry thats a lot to read :-)