Mishako129

Hi everybody. I am asking that someone would kindly help me out here.

I have a 1991 Accord with 300k+ miles on it. This is the problem.
When I am stopped and my car is in either reverse or in gear (d4), the cars revs will drop very very low (100 to 500 rpms) and even stall out (lots of shaking). It usually does this when I have parked it in a parking space and right as I am moving out of it. Or when I just start the car up. The car does fine in P or in N.
The revs drop faster once I let the brake off and allow the gear (either reverse or d4) to move to car by itself out of the parking space (without me touching the gas). This is when it will usually stall.


To try to fix this I've cleaned the IACV (it was VERY dirty) and I tightened the FITV (but I did not clean it, should I?). I've also burped all air out of the coolant system and adjusted the idle screw (this did not really help, it just masked it over). The only other possibility that I heard it could be is a vacuum leak, but I don't know how to search for those.


Thank you all and God bless.

nus_dogg

Also clean out your TB. If there's gum/varnish build up in there, it'll cause a low idle as well, because our cars uses the IACV and air by the blade(TB) to maintain the idle.

v4lu3s

did you adjust the idle properly or just messed with the screw? properly means do it once the engine is warmed up and unplug the iacv THEN adjust the screw.

Mishako129

Oh. My. Gosh. I just got done cleaning our the EGR valve and found myself in the nastiest dirtiest job ever. There was SO much soot and gunk.

I also cleaned out the throttle body... The next this I guess to do is either get a new IACV, or look for a coolant clog in the IACV, or maybe a new FITV. The idle screw changing thing is not going to work for this.

Cleaning the EGV valve DID help, but its not completely fixed yet.

That EGR valve was NASTY!

v4lu3s

??????????

nus_dogg

OP, what step did you take when adjusting your idle?

SonnyBlk

How does it idle when you start it on a cold morning?

Mishako129

The car starts very roughly and then it dies. I have to press the gas to keep it alive, then once warmed up a little it idles fine... Makes me think the FITV is the problem. Does anyone know how to clean the FITV? I think I know how to test it to see if it works.

SonnyBlk

Thats what i was leaning towards.. but also check that the temp sensor to the ECU is connected and working properly.

as far as cleaning it... Search my friend. I googled "FITV" and the first link was how to clean it. ;-)

Mishako129

Just got done cleaning. I didn't notice much change but i'll have to see tomorrow morning when its completely cold.

I saw that on the FITV cleaning guide he said this,

"
Side view shot through the hole. It isn’t screwed in all the way since my car idles fine at that position. Screw it in more if your car idles to high. The opposite if it idles to low."

This whole time I was trying to screw it in tight as possible but he is saying here to loosen it if the car idles too low, which my car does... does this sound right?

This is what I speak of. I've always read on the web that tightening it works to fix idles but the guy here says to loosen it if the idle is too low:

https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/






Just as importantly on another guide for helping idle problems, the guy spoke about how to test if the FITV isn't working correctly. The way he said you do this the following:

http://www.hondaaccordforum.com/foru...e-probs-14691/

1. Separate your intake tube from the TB and look inside, you will see 2 holes... the picture below is self explanatory:
2. Now start your car and let it warm up to normal operating temperature (fan comes on), then put your finger in the FITV hole, there should be ZERO to VERY MINIMAL suction:
3. If there is suction after warm up then there is something wrong with the FIT valve, turn the car off and let it cool down.

4. This is where the manuals tell you to change the FIT valve with a new one, but there are actually a couple of things you can do to "fix" it. First things first, this is what the FITV looks like, it's attached to the underside of the TB or in some models it will be attached on the manifold right under the TB and it may have 2 coolant hoses, mine has one on the FITV and one going to the IACV from the TB (channeled through the FITV):




My FIT valve was making a lot of suction at a few times after I got the car to normal operating temperature... I guess this means that I need to replace it? This was after I cleaned it that it made the suction... Maybe I just need to loosen it now.

v4lu3s

have never seen a FITV that is flowing too much air lead to a low throttle, the FITV leads to a surging/high idle almost every time.

what does the car idle at with the IACV unplugged and warmed up?

Mishako129

I would have to check the idle in either D4 or in Reverse because it ALWAYS idles fine in N or in P... its wierd I know, I think I have a vacuum leak.

Mishako129

this morning it died a few seconds after i unplugged the IACV...i guess this means it works?

Mishako129

I think the IACV is good. Do you guys think that a bad cap/rotor could cause bad idle in R or D? I replaced the plugs and wires already. Maybe its clogged EGR Ports because when I cleaned the ERG valve it seemed to run a whole lot better... or maybe its a combination of things... it could be electrical. It idles high in P or in N, but in R or D the revs will drop very very low and sometimes even die...I think its a vacuum leak or somethin'. The only thing is where am i supposed to look for leaks on the accord? I tried to use brake cleaner to find a leak but I have no idea where to look on the engine.

Could someone please show me where to look by using this picture? :

v4lu3s

it means your idle it too low. it means you need to warm it up, unplug the iacv and only then adjust the idle screw on the throttle body.

Mishako129

I already adjusted the screw. The idle was actually high during the time I disconnected the IACV.

When I start the car up or put it in P or in N it idles high (1000 or 1200 rps) then it will go down to like 800 or 900 after a few seconds. It idles high because I adjusted the idle screw with the Chilton manual and made it too high.The reason why its high it because of the real problem with the car: The idle in D4 and in R. The problem in D4 or in R is that the idle goes down to about 100 to 600 rpms and even dies. I tried to adjust the idle screw according to D4 and R idle speeds, but at the same time making the idle in P and in R too high (I had to do it to help the idle in R and D4). It still did not fix my problem.

I was suspecting a vacuum leak to be the problem.

v4lu3s

vacuum leaks almost always lead to high idle unless there is a fuel problem.

your car SHOULD idle high when you first start it, that is normal while it is warming up. the iacv works by creating a vacuum "leak" leading to a higher idle when there is a load on the engine. If you have properly set the idle by warming the car up to operating temperature, unplugging the iacv and setting idle at I believe 650. setting your idle too high or too low can cause a hunting or surging idle. If the iacv is not working properly then it will not increase idle when under a load, such as when the car is in gear and stationary, or when the ac is on or the alternator is seeing a high load on it.

Mishako129

Well I can say for certain that I have an "idle from hell" and I still have not figured it out.

UPDATES:

-I forgot to tell you'all that my car vibrates / shakes VERY violently in the 100 to 700 rpm range. But it also does this in the higher rpm's (800-1200) just not nearly as violent.

- I've recently found out that cylinder 3 is not firing because I unplugged the spark boot and nothing happened. I need a compression / leak down test to be sure its a dead cylinder. I know I have spark + fuel getting to it.

- I've found out that it could be the distributer, the alternator, the IACV or the fuel pump.

My next question is: Can these idle problems be isolated to a dead cylinder or should I check the other above mentioned suspects?

My guess is that all of this violent shaking could be attributed to a bad rear engine mount as I already had the front one replaced. But im not sure. Maybe it runs like crap because of the dead cylinder, im trying to look for other reasons why it runs so crappy because I am pretty sure 1 dead cylinder would not effect the accords idle like this to make it stall out (the idle and stalling is regoddamndiculous).

One more thing: Can a frozen / stuck piston ring cause no compression in the cylinder? I was reading this thread about oil consumption and stuck rings, and using MMO or SeaFoam to un-stick them: http://marketplace.honda-tech.com/sh...2767274&page=1

(I also have insane oil consumption (1 qt every 200 mi) )

Mishako129

Its been a while since I posted here but I have updates for the situation. I just rebuilt the car, I put new pistons and rings in it and cleaned everything out, but the exact same thing is happening except only on cold starts before the car has fully warmed up. The idle is low and it vibrates when the car is in either R or D4. When it warms up it goes away though. Its not a motor mount. I cleaned the IACV and the FTIV recently and adjusted that. The idle has been set properly, I did it by the book.

I don't know what it could be. Maybe its the distributer having an internal oil leak? It does have an internal leak. On top of that there is a very slight, what sounds like an electrical misfire too when its warming up in N or P. It could be an electrical load bearing issue since it only does it in the drive gears, its like its not getting enough power maybe cause its not fully charged up yet. I don't know. The reason I suspect that is because there were times I hit the brakes and the headlights would go dim... I would like to get some tips on this please.

BrandonDrums

Don't you hate it when people ignore posts? Dead threads are my pet peeve.

I'm more of a subaru guy but the issues you're having sound similar to the gremlins older subies face. Basically I think you have dirty electrical grounds that's causing issues with several sensors, solenoids and relays.

Subaurs have this all the time because they are so frequently found in colder weather environments and are subject to more road salt and rust. However, all cars if driven long enough will start to have dirty grounding connections as dirt, rust and vibrations cause the connections to get clogged or move around.

Go get some di-electric grease, a little metal brush and some brake cleaner. I imagine all of the grounds are connected with 10mm bolts since that's standard for a Japanese car. Go in and find all of the places where you see electrical wires that aren't on actual electronic plugs in the engine bay and clean them up. Brush off the dirt, scrape off the rust and tease up the metal to expose the surface to better metal to metal contact. On painted areas, I like to use brake cleaner to strip away the paint which can be an insulator and use the di-electric grease on the surface to better protect it against future rust and aid in the connection.

In the subaru world, guys actually install aftermarket grounding kits with high-gague wires etc. because the problems are so persistant. You probably don't need to go this far but it shows how frustrating grounding issues can be.

The reason is that every sensor and relay in a car these days is reliant on voltage, not amps to relay their data. TPS sends it's info to the ECU by varying the voltage based on throttle angle, O2 sensors and MAF/MAP sensors are on a voltage scale of 0-12v to translate how much air and oxygen they are passing along.

If the voltage is inconsistent or varies from one part of the car to the other they can't stay calibrated with eachother. Considering all of the work you've done I imagine this is the issue.

Too bad it's been 8 months and you've probably sold the car ;-)



http://www.subaruoutback.org/forums/...nding-mod.html

Rick Pearson

It's not anything on the engine. It's your Torque Converter in the transmission. It's sticking in lockup mode. An entire engine rebuild wouldn't fix it. You need to work on the trans.