Heres my situation:
1988 CRX Si - After running the car for about 15-20 minutes, I will often get a increasing rpm (to about 2500) or sometimes when crusing at about 2500 rpm's, the engine will just stay at that speed, proceeded by intense shuddering, as if the coil was going out. This usually lasts about 10-15 seconds, then everything returns to normal. If I turn the car off while the engine is racing at 2500 rpm's, when I go to re-start it, it turns over, but will not start. After waiting about 20 seconds, it cranks right up. I am 99% sure the problem is electrical. I changed the main relay, but the probelm continued, so I put the old one back in. I have a new igniter, but I have not tried that yet. I am going through this methodically and want to change one thing at a time until I figure this out.

Besides a bad EACV, waht else would cause the intermittent high idle? Would this also cause the car to shudder as I described, then not start?

Any experts out there, please give me your thoughts. Thanks in advance.

 

ttt

Anyone out there have any ideas? Thanks!

 

Vacuum leak

 

i had a similiar problem when i wasnt running my eacv, once i got that wire fixed it ran beautifully... do u hav any codes?

 

no codes

 

wow, thats a weird one. free bump atleast. the shudder and no start thing is very strange.

 

Let me add, the engine will race up even when moving - not just at idle. Will a bad EACV increase engine speed at speeds other in addition to when idling? I need help on this one. Where are you experts!!!! Thanks to all for your ideas.

 

YES THE EACV will do this, if the stepper motor sticks or is carboned up. even when cruising.
make sure there is no carbon buildup on the screen!!!

 

Thanks for your reply. So far, I have narrowed a few things down. I replaced the main relay and it had no effect so I ruled that out. I replaced the O2 sensor and it made a huge difference. No more shuddering as if the coil was going out. I guess the dirty O2 sensor was sending eroneous codes to the ECU which in turn was sending bad signals to the MPFI system. Now, I have the intermittent high idle. One thing I have noticed, when the high idle is present, there is a very distinct delay in the engine response to the slightest touch of the accellerator. When the engine returns to a normal idle, the car accellerates smooth as silk. Does the EACV have any effect on the engine at RPM's above the specified idle speed. What about EACV affect on response to increases in throttle? I am not seeing the typical "bouncing" idle with a bad EACV, just a high idle. What about the TPS? Could this been the source of the idle problem?

 

a bad throttle position sensor will can cause the same effects as described above

 

OK - got it all sorted out and fixed. I hope this helps someone else. After replacing the O2 sensor, there was a significant improvement in the egine performance. No more stalling, shuddering, etc., but the idle was still not right. Basically, once the car warmed up, the idle was high (about 1500 rpm's). I was just about to order a new EACV from Honda thinking that was the problem when I decided to try something else first. I changed the temperature sender (under the distributor) and after 25 minutes of warming up the engine just purs at about 650 rpm's. No more idle problems. Drove the car about 50 miles this morning without a problem.

Moral of the story, change the cheap easy things first unless you are 100% sure of the cause for the problem. The O2 sensor was $40, the temp. sender was $18. Fixed - never ran better!

 

glad to hear the your whip is all up and running good

 

Hey man, glad to hear everything is running good again, and kudos for not following the H-T be-all-end-all solution to any car trouble (1-Main Relay, 2-Clean the IACV, 3-Replace VTEC Solenoid Gasket/screen, 4-Seafoam).

Thanks for posting up your solution, hopefully this will help out some others in the future.