ok so i just got everything hooked up and start it but it wont start up. checked the dizzy wiring and it was wrong(no spark) changed it and it and got spark and the engine took about 20 cranks to start so it starts very hard. This is on a p28 chipped with a gsr map

ive tried alot of things. fuel is there, spark is there but when it starts it fluctuates from 200rpm to 900 rpm and shuts off randomly. its only throwing the code for vtec solenoid even though o2 is not hooked up or vtec switch. its not throwing codes for those.

once started and i tap the gas it shuts off. starts alot easier with starter fluid also.

could the dizzy be bad.


ive checked timing which was dead on. fuel is 45psi but decreases to 0 once the fuel pump shuts off. and when the car starts it fluctuates from 40-50 or so but doesn't drop more.


i am lost on what to do ive replaced the throttle body like 3 times. changed ecus.
even if the coolant lines and some sensors are not hooked up it should start but throw the codes after 3 seconds. I do this like every other engine i swap in but this one doesnt want to run right

 

ohh sorry obdI gsr into obd0 crx with conversion to run obd1 ecu

 

check your valve adjustments, if the valves are off then it can cause this, or you may have a few valves that are adjusted and arent opening far enough. do you have adj cam gears? check to be sure those are dead on too, your camgears may be off a min or 2.

 

also wanna add, are you sure your firing order is right?

 

firing order is right this engine was running days ago so it cant be something like valves or internal wear. i will check compression tommarow though

 

the fuel pressure isnt suppose to fall to zero when you turn the car off, it should drop maybe 10 psi max. That would also explain why its hard to start, it needs to build fuel pressure after everytime you shut it off.

 

id check for leaky injectors if your pressure drops right when you shut it off

 

It's true, your FP should not fall off so quickly, something is up with that.

Also, because i helped with a similar built recently, are you sure all 4 injectors are working properly? We had that issue, because the engine had been sitting so long, the injectors were a bit gunked up.
Now here is the crazy part, i checked with a couple other good mechanics, the said the hit each side of all 4 injectors with a wrench to maybe free up any junk inside ( i was thinking, yeah right)...anyway, we did it, and the car fired right up and never ran better, lol

 

could be leaky injectors, there also anti drain back valves in the fuel pressure reg. and the fuel pump. the regulator is pretty easy to check, clamp the return line as soon as you shut the car off(and only with the car OFF) and see if the system now retains pressure.

 

werd
thanks for the tip guys
it has a aem fuel rail/reg. and i know my old car use to drop fuel pressure to


but ill clamp the reg. and see if it drops it
and like i said once it starts it doesnt run right either
i tap the gas and it stalls will not respond at all

 

if i dont get it running today ill get a video of what its doing

 

changed the regulator for fuel and the fuel seems steady now an ddoesnt drop less than 30 even when car is off.

still wont start now. like i said timing is on, spark is there, and obviously fuel is going to the rail

 

I know this sounds silly, but I've done it before after swapping my CRX. Do you have the spark plug wires on the correct ports on the distributor?

I drove my CRX around the block after the swap and it was loping like a Harley, thinking...something's not right. lol

 

no happens to be correct

 

Do you know for sure all 4 injectors are working?

 

today ill take off the rail and see if they spray
ill update results

 

ok just checked the injectors and they are firing but they fire at the same time dont know if that makes a difference they dont have a rhythm just all 4 fire at every .5 second or so dont know if thats normal

and both wires to one injector clip are positive dont know if that matters. meaning both wires are power when car is on and i test the wires with a test light both show up as power wires. i though one would be ground no

they fired fine though fuel sprayed thoroughly

 

Both of the wires arent positive, When you have the car on but not running both wires will light a test light. Just for anyone on here reading this, a test light is probably the shittiest electronic diagnosis tool there is. The ONLY thing you should use it for is checking fuses, and even that can give you a false "positive" Unless you have the car running your light is always going to stay lit and heres why. With the key "on" your injectors have a constant 12v to them coming in on one wire. The other (ground) wire goes to your ECU which has a transistor inside of it. When running the ECU will "pulse" the injector ground off and on to spray the injector. Since the car isnt running when you're checking the injector it has 12v sitting on both sides of the injector because the injector isnt grounded so it cant "use" the 12v. In other words it's not acting as a load. If you're trying to use the light to check for injector "pulse" the only thing you can do is start the car and use your light on the ground side of the injector and watch it blink......and thats all. You don't have the right tools to properly check injectors i'm sure (osciliscope, injector drop tester, and a fuel presssure gauge)

 

osciliscope, noid light, and a fuel presssure gauge
i have all those haha
i have a shitload load of tools.

thanks for the explanation. and what about when they fire dont they fire separately instead of all 4 at once

 

You have a scope but you're using a test light???? I sure do wish I could smack you lol, do you actually know HOW to use the scope though? If so, look for your pulse width on your injectors. And most likely your injectors are pulsing so fast that it just looks like a constant spray to you. You need an injector drop tester in order to see if you have a clogged injector. If you have pulse width and you have a even drop across your injectors for the most part you can rule that out....

 

Also you said some of your dizzy wiring was already screwed up, you need to get a hold of a wiring diagram and see which sensor sends your signal to your ECU for injector pulse. It's usually a "camshaft pos. sensor" who knows that it's called on different models. But that sensor should actually send the signal or what cylinder is on the compression/ power stroke so it knows what injector to fire. Could be a chance that signal wire is wired wrong.

 

well with the noid light i could see it flashing so i guess ur right it may just be too fast for me to see with my eye

heres all the things for the distributor those are the dizzy wires and what they are i can not translate what they mean though ha
i just used the bottom of this page
http://www.boomslang.us/obd0_1.pdf
to do the conversion from obd0-obdII
CYPP
CYPG
TDCP
TDCG
CKPP
CKPG
ICM
IGN Output
Tach Output

 

on the boomslang it has something for tps it says this

At the TPS connector on the OBD0 engine harness, switch the
two outer wires (green/white and green/yellow) by
cutting/splicing or re-pinning them.

i didnt do this but im not using a boomslang harness do i still have to do that

ohh and right now i cant even get it started

 

All four of the injectors fire at start up. They won't start pulsing individually until the engine is started and an idle settles.

 

ok yeah than they are working fine