Dasfinc

Finished up my Y8 mini me swap, and ironed out all my issues except for one.

The car starts and idles perfectly, revs smoothly and quickly in neutral or with the clutch in, but with the car under load below 5 grand it is stuttering and misfiring pretty badly and is to the point of being nearly undriveable once its warmed up, once it hits 5K and the cam phases, the car runs ALLRIGHT, but still not correctly, and is still missing badly.

NO Check engine light, Isn't burning coolant or oil, Smokes a bit under load, but it just smells like its running rich.

I fixed my timing last night and its dead on at 0 degrees, but still has this issue.

Anyone have something of this nature happen to them before?

Car is a 92 CX with a D15B8 Bottom end, and a D16Y8 head, Yes the Oil jet has been Pulled, and Yes the ECU is correct, and AGAIN there is no CEL. some input would be massivily helpful

ECU is correct, Timing has no affect on the problem, Spark Plugs wires are good *Tested another set*

My IAT is mounted off a Vacuum line, but shouldn't be causing this problem.

I took the injectors off and cleaned them, and tried another FPR, still the problem remains.

Does this all sound typical of a Ignition coil failure?


Modified by Dasfinc at 8:56 AM 11/30/2007

97Ej6mike

From the sound of it, the first thing that would ring true to me is a busted Map sensor. Check to make sure its functioning properly and that its nipple is not clogged with debris, which can happen on some occassions. If the nipple were to be obstructed, it would not read correctly, even tho the sensor itself is not broken, therefore running much richer than you would need and NOT throwing a CEL, because the ECU reads it as working.

Dasfinc

I took it off to take a look at it earlier in the project and put it back on its respective throttle body, is carb cleaner safe on something like that? or do I need to buy that stupid electrolite cleaner stuff.

I'd be really surprised if that was my problem though because I've used the same map/TB on all 3 of the heads that have been on this car.

although I do suspect something sensor related is causing this problem as the mechanics are almost all new and redone.

Phearable recommend I advance my timing maybe 2-3 degrees to see if this helps, anyone oppose that suggestion, I have a fairly large number of things done to the car now, as well as I'm a fairly high compression motor *somewhere between 10.8 and 11.1 : 1 CR*

*Edit* Timing has no affect on the problem.


Modified by Dasfinc at 8:57 AM 11/30/2007

Dasfinc

Bump, MAP sensor got cleaned out as well, problem remains.

hatch96y7

try disconnecting the iat sensor and see if it runs a liittle better after warm up.
cause i have some what the similar problem

Dasfinc

Phearable had told me early on when I asked about that its not likely for the iat to be causing a problem this dramatic without a CEL

hatch96y7

same with me when i have mine connected it runs like total **** but when i disconnect it it runs better but throws the code just try it and see if there is a diff

Dasfinc

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hatch96y7 &raquo;</TD></TR><TR><TD CLASS="quote">same with me when i have mine connected it runs like total **** but when i disconnect it it runs better but throws the code just try it and see if there is a diff</TD></TR></TABLE>

I'll give it a go, Thanks for the advice

I have a new coil to throw on tonight as well, I'll try unplugging that first to see if I can just return the coil $$$

hatch96y7

why dont u test the coil first instead of just replacing it

Dasfinc

Cause the car still runs and drives, just struggles under load, All the tests I saw are if the coil was dead.

hatch96y7

no u check resistance with an ohm meter if the readings arent correct u change it.
if the readings are within range u keep it

Dasfinc

Do you have a link to that writeup?