A couple of weeks ago it rained really hard and flooded the streets. Before I could get off the flooded roadway, my cold air intake managed to suck up a bunch of water into the engine (that killed it instantly ). Well, because of that I tore the engine down and gave it a full re-ring. Naturally I changed all the gaskets and installed new timing belts... everything was done by-the-book.
Now I have the car all back together and it starts right up, but has a couple of problems. Firstly it idles too low and will most often just die. Secondly it has a horrible "lag" from idle to about 2500 -above 2500 it does well.
I've replaced the O2 sensor since it was likely that it was fouled when the water entered the engine and also rechecked my cam timing. If I advance the timing using the distributor it runs better and gets rid of the lag, but I have to advance it beyond what the notches in the distributor allow. I've also insured that I have no vacuum leaks.
Anyone got any ideas on what might be the culprit here?
Thanks for any input.

1994 Prelude, H23A1 A/T

 

Did you adjust the timing tensioner correctly? Sounds like maybe it isnt tight enough if you're losing power between those rpms...

 

Yeah, it's correct -checked, doublechecked, and even triple checked after I got the motor running again.
I get the feeling that perhaps the water that entered the intake fouled another sensor... the only problem with that theory is that I'm not getting any trouble codes.
Since my last posting I've started on a leak-down test of the cylinders. The short-term tests are good so far... I even went as far as installing the old ECM (I'm using an AEM 1040) just to see if that made any difference... it didn't.

 

Certainly sounds like a sensor, do you have a multimeter of some sort? start testing the readings from each sensor... you can download the Honda service manual for your lude from here(just sign up and go to "Manuals" link on main page) http://www.hondahookup.com/manuals/

List as "Honda Prelude (93) Service Manual(38Mb PDF)"

Also, you throwing any codes?? make sure you drive it around a bit, I think it takes a couple drive cycles to pick up intermitten sensor failures...

 

I'm a member of HondaHookup too... thanks for the link, tho.
I hadn't thought about intermittent codes not showing up right away. I'll have to take the car out in the morning and put a few miles on it and see what turns up. Only problem is that I'll have to advance that timing a bit to keep it running at idle...
Thanks for that idea.

 

One more thought I have, is it possible the EGR system is stuck open? The EGR system should only be open between like 2l and 3k rpms or something like that, if its open before that maybe its stuck and causing it to stall? Also if it were stuck open it wouldnt cause a problem in higher rpms...just a thought...

Also maybe check for vaccum leaks/leak in the Intake manifold...

All just thoughts..

 

From another site

 

Alright, I've checked many other sites, and most seem to point to the EGR... Post back when ya get a chance....

 

Thanks very much for all that input. In the morning I'll rip that 'ol EGR valve off and give it a good inspection and cleaning and see how that does. I'm sure water got into it when I had that little "incident" and I had overlooked it until you said something.
My first guess on this whole issue was a vacuum leak so I went back and made sure all the manifold bolts were good and tight and then did a leak test using a propane torch.
I took the car out for a good twenty minute spin around town just now and noticed that the problem seems to be intensified as the engine gets to full operating temperature, though advancing the timing did help a lot (kept it from dying at every red light!).
I'll post my findings in the morning... Thanks again for the input.

 

If it intensifies at full operating temp., the possiblity of it being the EGR becomes alot more realistic... If it is the EGR, full temp is when you'd notice the prob. the most Hopefully this will be a quick fix