So.. i just recently purchased a 2001 prelude.. its beautiful 99000 miles.. it has an h22a of course... but was swapped from an auto to a manu.. and has a m2s4 tranny shifts and drives relatively smooth.. im pretty please with its performace.. i was told it "has all obd2 stuff from factory, but is running an obd1 chipped p28 ecu with an obd2 to obd1 jumper harness." he also said he used chrome for the software, it has 3k laugh control.. etc.. im not sure if any of that is relative to the case but i figure id tell ya just in case. anyway so from a cold start it idles just above the bottom line, so it barely registers and wants to stall eventually itll bring itself up to around 1200rpm.. then since im in florida and its hot, if you turn the ac on iy goes right back to barely registering and stalling,, if i try to drive it.. it boggs and trys to stall without the ac on its okay, if its warmed up.. with the ac on i can drive it and the ac works it drives and runs beautiful but as soon as i take it out of gear and rpms slowly drop below 1k it stalls.. same thing at stop light.. i feel like everyone thinks i dunno how to drive it sucks anyway ive been doing some research and cleaned the iac valve (I think) i used a can of carb cleaner on it but it didnt solve the problem.. i was next going to attempt the egr valve.. i just need suggestions,, the person i bought it from swears its a vacuum line but i dont see how it only has like 3 vacuum lines left.. that i can see ill post pics.. any help would be appreciated im driving myself bonkers thinking i bought a pos or something...

 

 

so yeah i seen how helpful you guys are on here any help for me would be greatly appreciated... thank you in advance..

btw here are some videos if it helps...

http://www.youtube.com/watch?v=R6JM7mPSu9M
http://www.youtube.com/watch?v=9uPvdtQ9zCM
http://www.youtube.com/watch?v=VK9WlVDeRKw

p.s. yeah my vss is screw, new one is on the way...

 

My 99 was doing the same thing, and it turned out the EGR valve was clogged.

Good Luck.

 

yeah but shouldnt it be throwing codes for this stuff? like egr insufficient flow or something cause my check engine light isnt on or anything...

 

well i guess since i cant get any replys.. im gunna start rippin this bih apart on whims and prolly makin it worse..screw it i cant wait.

 

well it was pretty caked up hopes this works... if not on to the next idea i guess..

 

well that didnt work... i didnt clean the ports though didnt have the tools to do it idk if i wanna go through it either it it dont fix it... i can smell that its running rich though anybody got any ideas? i need some damn help this is gettin on my last nerve

 

can anyone help me find a vacuum line diagram i guess im gunna go through that tomorrow

 

it sounds like u have too much freon in the system that will cause it to idle weird.... have the pressure checked to see if its over charged

 

Hi,

It's tough to diagnose this because it had a major swap and the lack of info.

Are there any codes? If there's any vacuum leaks you could spray some brakeleen around the intake manifold and see if the engine sucks it in temporarily sealing it and corrects the idle itself.

I would try and collect as much data so you can diagnose it.

If it's running rich, that could be due to a vacuum leak somewhere in the system. Basically the motor is sucking in "un-metered" air and this adds more Oxygen into the system. The ECU see's this from the o2 sensors and compensates by adding more fuel, and throwing a lean code but will never get it right at idle or at load.

 

^^ agreed, also, it may be acting weird because of the ports on the intake and throttle boddy that are capped off, no longer in use, it is hard to say, especially with it having a different ecu what exactly is going on, but the car is idling too high in the first place, the ac may be choking it down but I believe there is an underlying issue there besides the ac itself

 

EGR ports in the intake. They're a pain to clean but that's probably whats wrong. Also, it could be in the computer, since its got a custom tune.

 

This.

You can try seafoam, which helped mine for a bit, but I'd suggest having a pro drill out the ports for you, or just replacing it all together. Wiping it out and leaving the ports gunky wont help much. When mine gunked up it didnt throw codes for quite some time, and it might not at all with all the mods youve done.

 

sorry ive never dealt with a obd2>1 conversion... so im saying i dont know how to read diagnostic codes cause the obd2 and 1 plugs are different and i can only find an obd2 plug to plug into.. and besides that i tried using an obd2 reader on it... so im saying how do i read the codes if there are any? i mean the CEL is not on but maybe theres a history?

 

well i figured out how to check codes with the "jumper" technique.. there arent any cel codes but there were some abs codes... i guess i dunno im at a loss for words.. anyone have any other ideas for me to try?

 

If you want to clean the egr ports, you can tap the center of the brass cap, drill it out for a 10mm bolt, tap and thread the drilled holes and use compressed air and a long straight wire to clean the ports. Once the ports can be cleared, use some honda bond around the bolts and screw them into the ports. Easy and simple to clean if they get clogged again.

 

hmm.. skafia1 thats a good idea.. ill have to try that... im saying do you guys think that this problem could be associated with a bad tune? i mean it seems it runs and drives like a champ.. except for the fact that the idle is high when its warm and it drops to almost a stall when you turn the ac on... it sometimes idles okay once its warm and with the ac on but only for a minute and then the idle starts jumping back and forth between the bottom line and like 1200 and its not like the normal surging... its more like itll drop pause jump back up pause and drop and so on.... i dunno i wish i could really figure this out... i kinda wanna take it to a place with a dyno and a reputable tuner but what if it turns out not to be the tune and i gotta spend buku bucs because its anywhere from $75 to who knows to have them look at it lol... im just trying to narrow down the problem so i can actually put money into getting the problem takin care of not, spending money trying to figure it out cause damn thats the point i bought this car... easy to work on, good gass mileage, and reliability.. but damn i seem to be changin my mind about it lol.. anyway ill try the egr port technique but in the mean time what do yall think about the tune? its a p28 ecu chipped and he said it was tuned with crome.. i even research a little bit to see if the ecu was chipped right and took it out and took a look at it... id post picture but i dunno if yall would be able to tell if it was done right by pictures, if theyd help id post cause im down to try anything... let me know what yall think.. thanks in advance and sorry for the long posts lol.

 

Once you start tinkering with any car, the reliability is only as good as the tinkerer's tinkering skills.

Unfortunately it seems you got a bad tinkerer ...

 

ahh hell.. thats bs.. instead of giving me crap why not lend a hand... and there nothing wrong with my damn "tinkering skills" .. i bought the car like this and i already knew what the hell to check and see whats wrong with it and ive done as much as i can do which is why im asking for help..i am limited to tool since i just moved to florida, which is where i bought the car and all my friends are honda tuners and own them and ive always helped them with their cars.. just never had a problem like this.. but theyre back home and cant really drive 1200 miles to help... so sorry im unfimiliar with ecu swaps and ****.. but whatever bro i guess what im trying to say is kiss my a$$ f4gg0t... kthx

 

lol your gonna have to deal with a bunch of douchebags on this site. the only thing i can think of is the egr valve, or a vacuum leak.

good luck man!

 

I wasn't talking about your tinkering skill, you seem to be doing an awesome job communicating what your doing.

I was talking about the d-bag that made a rat's nest of your car to begin with.

 

I do have a suggestion actually, pull the A/C belt off.

You're compressor bearings could be going.

 

my bad then... one of my friends also suggested to pull the ac belt off, but im saying if the bearing was going that it would do it constantly, which it doesnt seem to be doing... and it seems that when theres extra drag on the alt like windows or you put the blower on high anything, that you can see it in the idle also... but anyway if i pull it off, see that its on the same belt on the alt.. what am i looking for exactly cause im sayin with those two things off its definitely going to idle differently.

 

Just pick up an alt belt that will fit and run it like that for a few days, see if your problem goes away.

My ex's civic died when she put the clutch in, and wouldn't even start when the compressor bearings went, that little D16 just didn't have the power to stay running. She had no indication that the compressor was dieing either, no noise or anything, it just died.