Shad0wcat

Any new news with this? I have the hesitation from about 1.5-3.5k and it sometimes throws an O2 CEL (not all the time though which is strange).

I have replaced the O2 (brand new) which is strange. I also did the EGR test by taking the vac line off the fuel regulator and putting it onto EGR, car stalled so I guess that is ok.....

Car is definately running rich...

nafreak

Got an appointment for 8am at the Honda stealership, so hopefully they can figure out what is going on. Ill post back and relay my results as usual. Wish me luck!!!

nafreak

well, I kinda expected to get the run around and I somewhat did. They always seem to blame it on aftermarket parts....

Said it was a valve adjustment, paid them $242 plus tax for that which included the $89 fee for "diagnosis". I had already done it like 4 months ago or so, and found all the clearances to be really tight. So I loosened them up to smaller part the adjustment range provided by the helms. After that the valvetrain noise was noticably louder. Im thinking that it was tightened down that close to conceal that problem before I bought it. Although it did stop stalling after I did that, so I must have done something right.

SO they reset the ECU and did a valve adjustment and it does run a little better, but the hesitation is still there. They recommended changing wires, plugs cap and rotor, but all of that is less than 6 months old, and also doing a compression test. They also mentioned about my exhaust and blah blah blah.....

So I am considering letting them do a compression test and changing out those things just to see how much farther they will go to try and diagnose this driveability issue.

Revi

Dude dont pay them for a compression test, you in orlando? Bring that boy over to my garage and ill do a compression test on it.

nafreak

Thanks to Revi we got my compression test done and I got 2 good cylinders (180) 1 that was a lil down(150) and one that is fuxored (80!)

Next thing is a leakdown test to let me know if it is the valves or the rings.....


Thanks again Revi!

JDMHATCHEG92

CHECK YOU ALTENATORS!!! I CHANGED MINE AND BAM IT WORKED I had a p28 and it still did it so i changed the alt and it workeD!

97LXF20B

^ ummm.. sounds like he's already headed in the right direction with the leakdown.

plikit

Just made progress on my 3k hesitation...

by accident.

i have a decently sized amp in my car 720W rms... not huge but big enough for me.
my headunit was stolen, so now the amp doesnt come on when my car does..
now my car runs great!
it had been lacking in the low end and had the 3-4k hesitation, which is gone.
another symptom i've noticed is that when i used to take my foot off the gas it was a very abrupt transition to engine braking, even this is gone.

it seems there's some strong electrical noise from the amp power wire (i ran it down the passenger side of the car). or maybe my amp was just putting too much strain on the electrical system? im really not sure.

sadly im out a stereo but my car is so much more fun to drive again

MarkLude2000

Well i have the same problem on my 2000 Lude.....So far i have cleaned my inectors,replaced the EGR valve for a hefty price of $260 to say the least, N totally gutted my Catalactic Converter nothing has really fixed the problem But the Egr vavle did help a little. Ive read all the threads n heard all the possible problems such as the knock valve,egr valve,distributor cap,timing,o2 sensor, ect. if anyone knows the cure please message me Im so frustrated

Mark,

PreLuder96

I am having the same problem. I am throwing cel 8 and 65. I am going to replace the 02 sensor in a few but I have already replaced the dizzy. I am at a lost cause I also have checked the timing and everything seems good. I have replaced the whole dizzy with new cap, rotor, sparkplugs and wires, still hesitates at 3k.

mugendc2419

well i had a very similar issue with my 95 prelude vtec and no one was able to answer it. The problem wasnt noticeable when cold and in rain and every rpm past 3,000 seemed ok. there was no check engine light. also the car had a full exhaust system with header and intake, full tune up replaced egr valve and cleaned tb. It took me a long time to figure out. as it turns out there is a vac system that opens valves inside the intake manifold to allow more air to flow into the motor past 3k rpm and closes to allow more fuel into the motor blow 3k rpm.This is bc a richer mixture is needed for torque and a leaner mixture for horsepower. srry i dont recall the name of the system but easy enough to find out. anywayz on my 95 the the was a vac box under the intake manifold that control this system to open and close the valves. in my case, a vac line had snaped off this box. I removed the box from under the car and was able to reconnect the line. this is where i would begin looking. check the lines to this unit/pastic box, and the box itself for cracks. I no the 5th gen has a very similar system but the way it is set up my be different. i hope the best to those with the problem from hell, if in some way this corrects your issue post ur success for the next guy.
-victor

mugendc2419

well i had a very similar issue with my 95 prelude vtec and no one was able to answer it. The problem wasnt noticeable when cold and in rain and every rpm past 3,000 seemed ok. there was no check engine light. also the car had a full exhaust system with header and intake, full tune up replaced egr valve and cleaned tb. It took me a long time to figure out. as it turns out there is a vac system that opens valves inside the intake manifold to allow more air to flow into the motor past 3k rpm and closes to allow more fuel into the motor blow 3k rpm.This is bc a richer mixture is needed for torque and a leaner mixture for horsepower. srry i dont recall the name of the system but easy enough to find out. anywayz on my 95 the the was a vac box under the intake manifold that control this system to open and close the valves. in my case, a vac line had snaped off this box. I removed the box from under the car and was able to reconnect the line. this is where i would begin looking. check the lines to this unit/pastic box, and the box itself for cracks. I no the 5th gen has a very similar system but the way it is set up my be different. i hope the best to those with the problem from hell, if in some way this corrects your issue post ur success for the next guy.
-victor

1funryd

So there are a few possbilites: Knock sensor, EGR, and alternator.

I have an H23a swap into a 88 Prelude, and this problem started right after I got the AC system working in this swap about a month ago.

I am running a P14 for a USDM H23A1.

I have a very short filter and a header and a catback.

I will be getting my P72 and having the knock sensor disabled, and ELD as well, so I shall see hopfully by this Saturday.

I did the tune up with wires, plugs, distributor cap, rotor and PVC valve.

My hesitation is getting worse by the day and I use my lude for daily driving for work.

I am hoping the ECU will take care of this, so we can narrow down the culprits and finally get a real solution going for this Hesitation issue for the H series motors.

niterider96cord

At 3000RPM the ignition control module sends a signal to the Knock Sensor. This happens so that the control module can test the knock sensor. Your Knock Sensor might be needed a check up or the ignition control module. Check both to make sure proper voltage and wiring is intact.

1funryd

Nope it was not the Knock sensor for me

Good news for some of us with this problem.

I solved my issue with the 3K Hesitation issue. I had a pinched vaccum line that comes around the Throttle body into my vaccum box.

I was getting so irratated with losing power just on taking off from a stop light or on a hill(that is scary!!)

I noticed that this 3k Hesitation only started after I got AC working for this swap.

So when I got to my work this morning, popped my hood and just kept looking. I did not notice that a vaccum tube that was under the intake was being crushed.

I noticed it by accident, because I was moving vaccum lines around to see if I unplugged one, and then I could not move one of them, so I pulled in out from under the throttle body neck and then all of a sudden my low idle jumped up and the engine sounded a bit more normal.

I started to back up and head toward the highway and my hesitation was gone, so I got on the highway and started off like normal, and NO hesitation at all!!!

So the solution for my 3k Hesitation and low idle was a pinched vaccum line.

The End!!!

codyh

Not sure if someone said this yet. But not only does the EGR valve cause this problem when its not working, but this problem can occur when you get to much carbon built uo in the EGR valve itself, and the EGR valves ports. Try cleaning the ports. Or maybe buy a GSR. lol

I have only seen this problemo with ludes. :/

holmesnmanny

I'm wondering if the knock sensor is the cause of all my issues passing emissions. I have tested or replaced everything and the only thing I haven't touched is the knock sensor. I'm wondering now if it's possible during shipment from Japan, for a jdm engine with a knock sensor to have the crystal inside of it internally to be broken somehow and this causing the problems being highlighted in this thread.

I am going to test my knock sensor wiring from the connector to the new ecu pin that's installed on my connector. If that tests ok, I am going to put a new knock sensor that I had purchased, but did not install because my jdm had one on it that was not damaged(atleast outwardly).

There is also a chance that the shielding that I got from a kit I purchased from a guy on ebay is not sufficient however I gotta wonder how much different it is from OEM wiring on a standard vtec prelude.

My problems were hesitation lately of up to 3k at which point it seems to clear up, but it actually blips right at 3k before smoothing out.

hondasdohc

Well i know what the hesitation is i had that problem for a while and fixed it. Its the iacv motor it causes hesitation issues on preludes. The three wire type iacv will cause this problem to on preludes you need to get one from a 2 wire for it to respond correctly. Besides that try cleaning the iacv or getting a new one it will solve the stumble/jerk back and forth at 3k or 2k at which mine was doing.

gstrudler

holmesnmanny, if your knock sensor is bad it will throw a code and put you into limp mode.

I'd never thought about the IACV before, but I guess it's possible. Maybe I'll try unplugging it sometime and seeing how the engine responds. I don't seem to have the problem as often now though it seems.

(-.-dustin-.-)

i would have to say it's probably the egr valve. my lude does the same thing when i run my stock ecu, but with my p28 , i guess it runs fine because the p28 doesn't activate my egr

JDM-h22a

I have the same exact problem cleaned iacv and was dirty and didnt help replaced cap rotor wires plugs alternator fuel filter fuel pump still problem. Also rear that when you adjust timing and dont loop the ecu it wull try to correct itself causeibg a bog. Then went and looked at cam timing and was off a tooth went to retime and still in the middle of that seeing as when I started didn't read my manual and saw that I had to take crank pulley off and side mount to get to the tensioner yay lot of work to do today to see if this could possibly be the problen

holmesnmanny

Here's the deal, if it absolutely does not do it until the car warms up it's simply the egr ports being plugged up since egr only works once the car is warmed up.

The best thing to do is to pull the IM, remove top half, pull the egr plugs and buy about 4 cans of brake cleaner/carb cleaner/engine degreaser and just start spraying the **** out of it, using the spray straws that come with the cans to get into deep into the ports and the egr rail.

When I got my h22a swapped in I was using the JDM IM which has the plugs welded over so I chose to simply grab an allen wrench and try to push up into the ports from the head-side of the IM. I thought this worked but it didn't even come close. What could have happened is the car itself started running like **** to whoever was the owner in Japan and they just junked it. I think this is what happens a lot of the time and has been the issue to most of the people in this thread.

The USDM versions IM have accessible plugs while the JDM versions are not accessible unless you have someone grind the weld off.

You'll note most of the people in this thread simply used a programmable ECU which turned off the egr system which fixed their problem.

I have not had the time to finally put my IM back on my car and run it, but what I did was I bought an h22a4 IM off ebay and used that instead of paying someone to grind the weld off my ports. When I do, I will update and confirm all this, since I'm confident this is the source of my really bad bogging which has gotten worse and has caused me to fail my SMOG test with high HC's and NOX. I have literally replaced every component in my engine bay which caused me to finally realize my egr port cleaning was completely ineffective.

I think when I got the engine it only had one port completely plugged but they all plugged up within the few thousand miles I drove it before shutting it down.

scarface1346

On my lude it was a combo of previous owner using crap gas and a bad primary o2 sensor started using premium gas and changed o2 and it stopped I also changed knock sensor for good measure. No more hesitation and car runs a lot smoother.

holmesnmanny

I still haven't been able to get around to doing my work I've been busy with school and it's just been so cold I just haven't attempted to mess with it.

One thing I will add is that I did have a weird shake when I would start the car. I changed the knock sensor which actually looked fine and the shake went away as I heard it would from somewhere else. I think when the engine gets banged around during shipment perhaps the crystals inside the knock sensor get cracked or something so it's a good idea to swap those out when you get a jdm engine, imo.

holmesnmanny

Ok, so I finally got around to buying a piece of shielded wire and ran it from the ecu to the knock sensor and I can say without a doubt that this finally solved my hesitation.

I am now 100% certain that my hesitation was caused by outside interference causing my knock sensor voltage to fluctuate which I now know to be the root cause of most of the hesitations that are talked about by numerous people in this thread. I previously just had an "unshielded" 16 gauge wire running from the knock sensor to the ecu.

What you need to do is buy a shielded wire, hook it up to the knock sensor connector at that end, then at the ecu end gently pull back the shielded metal and put a connector on that metal and run it to a ground. I ran mines straight to the battery. Then put a connector on the wire and run it to the D3 pin at the ecu connector. You'll be fine if you have two inches or less of unshielded wire on either end as is the way for OEM wiring (see any OEM oxygen sensor signal wire)

And that should fix it. This symptom will never throw a code cause the ecu just looks for a signal, it doesn't really know if the signal is wrong or not.