I have to start replying to forums because they help me immensely, and I always find the ones after the “couldn’t fix, to the scrap yard it went”
If you still have this problem, this is for you.
06 Ex, R18A1
Needed a motor, but after all of that, and then some…
Same issue, idles relatively fine. Revs to 5k when parked.
No limp mode. CEL for ECT, but not flashing.
Pull off, rev too hard, flashing CEL, limp mode, will not rev pass 3500rpm. Shifts funny. No power. Won’t crack vtec (not very exciting on a R18). If I baby it from A to B, I can keep it from going into limp, since I’m not asking the car for too much of anything yet. It’ll go into limp at 2500 or 3500.
Thinking my plugs or coils, changed them, problem went away for a good 10 miles. Random misfire, limp mode. Check coils, okay they were loose but maybe that’s just a fluke (my fault), torque em down. Turn car off, let it get out of limp mode, tested again. Boom limp mode.
So 8 bad spark plugs and 8 bad coils? (Not included the sets before all of those) The odds are not in favor.
FUEL INJECTORS, FI, FI, FI!
The stock fuel injectors on the R18, are absolutely horrendous and very sensitive. My rule now (for this model and motor) if you take the fuel injector out, and it’s good, it’s now bad. If you replaced your fuel injectors with scrapyard fuel injectors, 90% chance they are bad. If your two 10mm nuts on your fuel rail are not properly torque down or missing, your fuel injectors will react accordingly. Either buy 4 brand new injectors, put them in correctly and never take them out, change the seals, and test them, (compressed air is your friend here) or do trial and error with your injector collection and cross your fingers. In one instance, 2 of my fuel injectors provide a nice ‘mist’ while the other 2 are just barely getting it out. It’s there, sure, but as soon as the request is sent for a little bit more, they lose rhythm, and cause a miss. One or two misses might not kick it, but enough misses in a certain period of time, limp mode.
For you other go getters, if you stumble across this issues after doing some work, and your car will not start after having random misfires, it bogs, cranks no start, runs for 3 seconds and turns off, check your evap line running along your intake boot. Make sure you didn’t mix up your evap purge line, and your cooling line.
(Yes, they look the exact same, I did it, regretted it, next)
Despite having no return line to worry about. You will dump 2 gallons of coolant into your fuel tank. It will sink to the bottom, completely ruin your fuel injectors, and corrupt your fuel system. Check this by pulling fuel rail hose off (relieve pressure) and look for tint to the fuel color. If it’s green, you’re wrong, if it’s that booboo orange coolant color, you’re wrong. Drain and clean your fuel tank, scrap your fuel pump (or change the filter but I rec scrap it all), swap your rail, and your injectors, take everything out and crank motor with no plugs to get whatever contaminated fuel out of the cylinders. Consider replacing your spark plugs, if they get coated with antifreeze from bad fuel injectors, in a perfect world you might be able to torch them back to life, but in practicality, they will have also bit the dust. You’ll know because you won’t get any action off of starter fluid.
If you compression test, and you’re hitting high numbers, 200-210, you might have a coat of antifreeze on top of your pistons. Either your head-gasket is leaking, or your fuel injectors are spitting antifreeze. Get it out.
I’m getting 30 miles per gallon out of this bad boy. It was an absolute nightmare to get it going. I have taken every system apart, tested everything. CPS. TPS. MAP. VTEC SOLENOID. BELT. TIMING. COMPRESSION.
Some more things you can’t even find on the internet just for good measures. Don’t be me.
There is one forum I found with someone with the exact issue, and I’m here because I lost that forum and it helped point me in the right direction, despite OP scrapping the car.
Get new injectors. Pass it on. You’re Welcome and Good Luck.
This thread is very concise. Thanks OP