I finally got my built motor started, but its really not idling well at all. If it starts, it idles very very low, and revving it up juist kills it right away. My first start was different, maybe becasue it was cold. It wouldn't idle, but it freely reved up. it had that vacuum leak symtom of hunting rpm too.
I really need this thing running quickly. Help!

Here are a couple videos of how it runs: (Ignore the knocking, thats the exhaust hitting the rear sway bar, I have to fix it.

http://www.youtube.com/watch?v=wW8mOjGcF5Y

http://www.youtube.com/watch?v=1ZDIW8fB71A

And one video of when it randomly idled fairly well, I think it was a relativly cold start:

http://www.youtube.com/watch?v=Zi3mzuHfLaY


Modified by Eyal 951 at 7:29 PM 9/13/2006

 

What did you change on the motor. did you get larger injectors as well. the ECU needs coded for the new stuff to idle correctly.

Did you check for vac leaks?

platinum

 

try to set the base timing (i always do it when swapping in a new motor). Everything else is what platinum said.. make sure you have the proper ecu/injectors.

 

the injectors are stock. it does the same thing on the hondata base maped P28, and on the stock CX ecu.
Anything vacuum seems to be in order (pretty much new hoses too) so unless I seriously overlooked something, I don't think its vacuum.

 

Short video of trying to rev. It dies at the end. Disregard the knocking noise, thats the exhaust hitting the new swaybar, I have to have the exhaust fixed to clear it.

http://www.youtube.com/watch?v=1ZDIW8fB71A

one more video of just idle coming up as well.

 

one more:

http://www.youtube.com/watch?v=wW8mOjGcF5Y

 

no other ideas?

 

So that means the systems are working... but barely.

Things to check

cam timing
valve adjustment (you didnt make it too loose?)
compression test (see above)

other than that, its got to be EFI related.
Vac leaks, TPS, MAP, the usual.
Distributor is legit?

No check engine lights?
Did you mess with any wiring? Or is this a straight OBD1 virgin setup?

 

cam timing - Perfect
valve adjustment (you didnt make it too loose?) - Just did it today, .006 intake, .008 exhuast.
compression test (see above) - I could do it, but I don't think thats it based on what I've observed.

other than that, its got to be EFI related.
Vac leaks, TPS, MAP, the usual. - swapped map, unpluged TPS, swapped tps/map connectors.
Distributor is legit? - Worked fine 2 weeks ago, but now has new cap and rotor.

No check engine lights? - nope, not with either ecu!
Did you mess with any wiring? Or is this a straight OBD1 virgin setup? - straight swap using my old, known good, harness.

Only thing is Possible vac leak, but I can't find one, all my lines are new, and there arent many of em.

 

The car runs a lot better on cold start BTW.

 

This is very much so a pickle. What exactly is done to the motor that its built, do you have a wideband to see your a/f? Fresh built cars should only run long enough to check for leaks, after that off to the dyno they go to be broken in correctly.

 

The Build: https://honda-tech.com/zerothread?id=1717242

I had a base map done by Church auto so that I can properly break it in on streetes, and once thats done, it goes to church for dyno tuning.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Eyal 951 &raquo;</TD></TR><TR><TD CLASS="quote">The car runs a lot better on cold start BTW.</TD></TR></TABLE>

maybe its running too lean? did u check the plug color, when it idles bad?

can you check fuel pressure. Can increase/decrease fuel pressure?
do you have a fuel trim adjustment? VAFC? etc?

 

bump for some answers

 

I think it would be on the rich side if anything. They added a bit extra fuel in the basemap so I can test vtec to make sure it works before I hit the dyno. Church did the basemap, so I assume they know what their doing (I hope) Haven't checked the plugs yet, all stock fuel stuff. I tried pulling the vac line of the FPR to see if it does anything, and no real change. No VAFC, just Hondata S100.

 

I just pulled the spark plugs, and all 4 of them are very black and smell like fuel.

zero miles, just about 20 minutes of run time, under 3000 rpm:




Modified by Eyal 951 at 2:50 PM 9/14/2006

 

i say a bad tps, so try another tb. one you know will work. when i was running a bad tps the car could run off the lowest setting i put my adjustable fuel pressure regulator...kinda wierd and it shoulda died but it didnt do anything.

 

i just set ita couple days ago. I'd throw a code if it was bad.

 

i didnt throw any codes for my bad tps. try throwing the old known-to-work tb on to test it.

 

i just tried my old cx TB that worked on my cx motor, it doesn't fit on the studs. If anyone local has a tb I can borrow for a few minutes, that would be helpful.

 

if the spark plugs are all black, come out kinds wet and smell like fuel i'd say your getting an incomplete combustion at the obvious. I'd double check the cap and rotor; you said you put in new parts here maybe theyre defective, and then go sytematically spark plug wires, cap, rotor, coil, dizzy...sound like its getting almost too much fuel and reving the motor just dumps more in there that it cant ignite. But thats just a guess...

 

the cap and rotor are new, wires are new, and plugs are new. the dizzy was known good on my d15 cx motor 2 weeks ago. injecotrs sound fine, swapped FPR (still stock) and changed ecu's.
what else should I do?

 

i had a similiar problem when i put the second d series in my 94 hatch had bad idle and wouldn't rev. seemed like if i got spark i wasn't getting fuel and visa versa. we changed the whole intake and tb out stiil same problem. my buddy wound up rotating my wires on the distributor over one and ran fine. something about the dizzy timing w/ cam timing but i can't remember which way he rotated them. we put them back the way we pulled them off originally then we rotated them. i think the rotor button has to be up when # 1 cyl. is tdc. u may want to chk on that though

 

wouldn't it not run at all if the wires were wrong?

 

or run like complete crap and miss fire causing your combustion problem but i don't know that is just what happened to me but u may want to chk on the rotor position and piston position