240 wont start

[Einstein240]

I have a 1989 240sx i recently built the motor and now its back in the car. Everything is hooked up and the car won't start. There is spark and fuel. The car cranks but will not fire. Please let me know some things to check so I can get it running.

[Infinitiguy19]

Do you have any check engine light codes? Is the MAF sensor fine and working properly?

Way to many things it could be so can you be more specific please?

[Einstein240]

I trouble shooted the ecu and it reads no problem and the maf sensor is fine the engine is a ka24de everything was rebuilt back to stock. What other information do you need to know?

[liquid_cool]

I trouble shooted the ecu and it reads no problem and the maf sensor is fine the engine is a ka24de everything was rebuilt back to stock. What other information do you need to know?

this is a timing issue...think basics....air , fuel, spark...if you have all 3 and still its not running..then its a timing issue...try redoing the timing from scratch...to do this the easy way..start by removing the spark plugs...putting her in nutral...remove the valve cover...put a piece of paper towl in the spark plug hole of the #1 cylinder....bump engine..not crank..till said paper flys out..thats CLOSE to top dead center...find your marks on your crank for TDC..rotate by hand..(with a wrench on the cams works) to get the crank lines up for TDC...check the cams position ...make shure they point away from eachother but slightly upwards...if thats good....rotate by hand again to 20 degrees BEFORE top dead center on the crank marks...replace upper cover..and incert dizzy to fire on the number 1 position....now the timing should be base set...replace valve cover..but leave the dizzy slightly loose so you can advance or retard it by hand when the motor is running to fine tune the timing...

good luck

[J14cm7]

I am no Ka expert, my specialty is s14 sr wiring but wouldnt the CAS prevent him from having spark. Also wouldnt he be throwing a code if he were out of time? Again im no expert and dont claim to be but in my experience engines dont give spark if the CAS senses bad timing.

[djmatt79]

Electrical?? Harness?? If you got air, spark, fuel.

I'm guessing electrical or timing.

Just a thought.

[triple r]

I am no Ka expert, my specialty is s14 sr wiring but wouldnt the CAS prevent him from having spark. Also wouldnt he be throwing a code if he were out of time? Again im no expert and dont claim to be but in my experience engines dont give spark if the CAS senses bad timing.

idk about the CAS but to your other question, no. if everything is operating good it wont throw a code because everything electrical is fine. its a mechanical issuefollow directions by liquid cool and you wil be running fine

[J14cm7]

idk about the CAS but to your other question, no. if everything is operating good it wont throw a code because everything electrical is fine. its a mechanical issuefollow directions by liquid cool and you wil be running fine

Just because everything electrical is fine doesnt mean it still wont throw a code. The CASs primary and only function is to check and make sure your timing is good. Its going to throw a code, i believe 11 but dont hold me to that, if your engine is off time. They just dont throw codes if its bad. I just think he should properly diagnose the problem before he goes and tears his engine apart trying to fix something that isnt broken. My sr had similar problems and i used a little starting fluid sprayed through the intake and it started right up and has been running fine ever since.

[liquid_cool]

Just because everything electrical is fine doesnt mean it still wont throw a code. The CASs primary and only function is to check and make sure your timing is good. Its going to throw a code, i believe 11 but dont hold me to that, if your engine is off time. They just dont throw codes if its bad. I just think he should properly diagnose the problem before he goes and tears his engine apart trying to fix something that isnt broken. My sr had similar problems and i used a little starting fluid sprayed through the intake and it started right up and has been running fine ever since.

he said..and i quote...he has AIR...FUEL..AND SPARK!....if he had an issue ither with the cas or an electrical component linked to the system for fuel delivery..or spark...then he would have issues with ither fuel or spark!...ka's are really basic in terms..and easy to understand....dizzy spins...sets fuel charge...spins some more..fires ignition..really basic..if those are functioning...then its timing...with a ka..you only have to be off by 1 tooth for it to act crappy..if it even starts up......with your SR...it may be different..allthou..most engines that are FI work in a simmilar way...hope this clarifyes a bit for ya...allso..tone it down a hare man....we are not all experts around here..but allot of us know the ka front to back..and have had simmilar issues like this one..take care..and welcome to nicco.

[J14cm7]

Sorry if i came off aggressive. I understand the concept of the FI engine. The point that i am trying to make is that if his timing is off as you say, and it may very well be, wouldnt the CAS throw a code and then prevent him from having spark? In my first post i was ASKING if that would be the case. Since he has spark, air, and fuel, my point is that may not be the issue.

idk about the CAS but to your other question, no. if everything is operating good it wont throw a code because everything electrical is fine. its a mechanical issuefollow directions by liquid cool and you wil be running fine

This is what i was replying to: He is saying that it wont throw a code if its a mechanical issue. Isnt that the primary function of the CAS to sense a mechanical timing issue? Therefore it will throw a code and prevent spark If there is bad timing OR it is not working properly OR there is a wiring issue with it. Im asking you? You seem to know engines better than me.

[liquid_cool]

well the ecu is not an AI...its a basic function with primary checks....if all checks come back clear...it does its normal higher functions...if not it throws a code....in the case when you have air fuel and spark allready...the ecu wont be able to tell if the actuall timing is off..as it reads the crank angle sensor in the dizzy to fire injectors and the coil..as far as it knows...its running...thats why when you pull off the oem fuel rail...and spark plugs...it will still fire the plugs and spray fuel...to the ecu..every thing may be fine..

thats the easyest way i can describe it...but i see why your asking allso...it was a valid question..hope this helps.