Delayed Throttle Response

[alex61089]

hey guys whenever i step on my gas i get about 2 second delay to where the car actually picks up fast. So if im at a light and i step on the gas the car starts moving slowly but after about 2 seconds it actually reacts to me stepping on the gas. What could be causing this problem?I read that the idle control valve could cause a delay is this true?

Heres a list of what i have replaced or done that could affect this.

Replaced:Fuel FilterOil FilterAir FilterTPSSpark PlugsRan Gum out and REDLINE through the fuel systemCleaned Throttle bodiesRan the self diagnostic for the ECM, got code 55 (nothing)

I'm lost lol..

[kbflip02]

could be a bad coil pack or injector...try unplugging one of the coil packs one at a time...whichever one doesnt make the engine stumble more than it already is is your culprit

[alex61089]

could bad oxygen sensors be the culprit? i figured if they arent calculating the right mixture it will cause the engine to run lean, ect.

[yodawill2000]

That would probably through a check engine code.Have you tried cleaning the Maf element with some zero residue contact cleaner ??

[alex61089]

yes, but nothing. i think the oxygen sensors are the original in there and they might be a little messed up; i hope so. lol. i just ordered two new ones for 130.00

[alex61089]

poor gas mileage has been a problem since i bought the car. even when i swapped the old maf with a reman from napa nothing changed, even though it was causing my car to stall out, perhaps i might need a new maf?

[yodawill2000]

Ive never heard any good things about reman'd MAF's

Have you checked for a Knock sensor code ??It wont cause the check engine to to illuminate.

[alex61089]

yeah i checked and it comes up code 55 which is no codes. but.. that was about a month ago but the problem has been the same since i bought it. so im not sure...when i step on the gas i sort of hear a.... shrooom noise coming from the engine its hard to to explain it sounds like the air coming out? or something. not sure... possible vaccum leak?

[yodawill2000]

Could very well be.Lots of vacuum hoses in there !!

[alex61089]

i just replaced the engine coolant temp sensor today and the oxygen sensors. Those oxygen sensors were a pain in the a** but it took me about an hour to do.. i'll see if my pick up improves along with fuel economy

[yodawill2000]

Keep us posted !!

[unlimited]

I'm having the same problem as you Alex. Hope you find out what's going on, might help me out too

[yodawill2000]

UnlimitedHave you cleaned the throttle bodies and run a bottle of redline through it ??

That improved mine dramatically.

[ReDsT@R DRiFt@R]

A bad accelerator pump could cause that if the vehicle has one. Have you fixed it?

[yodawill2000]

J's are Fuel injected.Only Carbed engines have accelerator pumps.

[ReDsT@R DRiFt@R]

Well then my buddies snap-on program we used was saying some s*** bout it when I looked up my 92 240sx. Of course for a exploded view of fuel system it showed a vg30de setup and said it was for a 92 240sxse. I cant wait till he loads up the new Alldata program instead its way better. I thought when i read that it didn't sound right.

So did u find out what was up with it?

[unlimited]

Yoda, naw I haven't done anything to the J30 really. When you say redline you mean the octane booster product that you put in your gas tank right? Hm, is the throttle body easy to reach? Don't have too much money to put into the car but if it's hands on things that don't cost anything/much , I'm willing to spend time on it.

[yodawill2000]

Yes Redline goes in the gas tank, You can get a bottle at Pep boys,, 7ish bux ..When your there get a can of Intake cleaner spray.Cleaning the throttle bodies is as simple as taking the intake tubes off of the throttle bodies and spraying down the intake and the throttle butterfly.It gets coated with Varnish if not maintained.

[unlimited]

I'm at some websites and seeing videos and they're showing that I have to remove the the whole throttle body. Is that what I'd have to do or will I be able to reach and clean the intake just by removing the tubes? Looks like I'ma have to buy a torx screwdriver too, I think... lol. If so, do you know what size?

this is the webpage I'm looking at:

http://www.mobiloil.com/USA-En...?pg=1

[yodawill2000]

I didnt clean the whole intake.I'll do that when I pull the plenum someday.I just sprayed down the butterfly area.Super simple.Didn't need a torx.Just took the clamps off the tubes and got them out of the way.


Modified by yodawill2000 at 6:14 PM 6/25/2009

[GerryO]

Agreed. Even with my plenum off I didn't separate the throttle bodies from the plenum.

Also note that the CRC folks really have their act together, offering different spray cleaners for carburetors, throttle bodies and MAFs. The throttle body cleaner includes some lubricants to keep things moving freely and closing completely.

A bit of brushing with a good toothbrush (no loose/broken bristles) and careful wiping with a lint-free cloth with the butterflies held open might help. There might also be a couple of small vacuum hoses that can be disconnected in order to flush the throttle body ports that they connect to.

[unlimited]

Thanks you guys! Just went to go see if I would actually be able to loosen the clamps and take that part off and was able to (was easier than I thought.) So I opened up the butterfly flap and it wasn't as dirty as I thought though it's pretty dark outside and didn't try to look to much into the flap. I'm not sure what a dirty throttle body looks like. There is some sticky type reside inside but not sure if that affects anything too much. Did go to Walmart and bought some CRC Throttle Body spray and will buy some Redline later on today. The CRC was pretty cheap actually :3. So is it basically spraying the inside, cleaning it with a tooth brush, wiping with a cloth, and spraying again? Just like to be super sure, lol.

So tomorrow guess I have some things to do

BTW, what's this about?

"There might also be a couple of small vacuum hoses that can be disconnected in order to flush the throttle body ports that they connect to."

Also heres a pretty bad cell phone photo of one of the throttle bodies

[yodawill2000]

Yeppers And learn from my mistake lolthe little plastic tube on the CRC can ??Make sure it doesn't fly off into the Plenum !!!hehePut the Redline in when the tank is low ..Then fill it up to about 1/2 to 3/4 full.That will give ya a strong dose.And put it in a low gear and rev it up a few times after you drive awhile.That will help blow some crud out.

[unlimited]

welp, im back. just got done cleaning out both the throttle bodys. everything seems to be kind of okay but now my car is idling at about 1600rpm in park when it was alittle under 1000rpm before i cleaned it out. i havent gotten a chance to put the redline in yet but i did buy it. i put 20 in the tank yesterday and my cars half full so gotta wait til thats down.

after i finished everything and hooked all the tubes back up i tried turning the car on but it just kept making that noise as if the battery was dead. tried it twice for 3 seconds and nothing. third time i did it for about 5 seconds and pressing on the gas then it finally came on (thank god.) so that problems gone and its starting up just fine now, im just not liking my new, higher idling in park. i drove it for 30 minutes on the road and on the highway and it seems smoother and pressing on the gas actually makes it go but not too much of an improvement. hoping the redline will help it out alittle.

here are some before of how both sides looked, and after





i think after the after photo, i sprayed it alittle morethat CRC is like magic o.o was crazy, lol

[GerryO]

Don't know if you had some sort of hydro-lock or fouled plug condition after squirting so much liquid into the plenum (a few intake valves had to be open) and maybe an oil change is a good idea, depending how much CRC got past the rings.

What lies behind the butterfly valves is important too and they should now be closing more completely (and at the same time), meaning the position of your TPS should be different, so you'll at least need to check/re-adjust the TPS output voltage, which should lower your idle speed.

Also make sure that you have the necessary amount of slack in your throttle and cruise control cables, and that they move smoothly.

[yodawill2000]

We need to hook up U.I can check your TPS voltage with the consult.

And Gerr.I always thought about that solvent in the crankcase thing but Q45Tech mentioned most all that stuff evaporates when up to operational temp.Just thinking out loud again.. Hehe

[unlimited]

If you would please x.x

Still a noobie with all of this, lol. Anxious to use that bottle of Redline though. I'm bad with buying new things, I always wanna try it out right away haha. Hm, how exactly do I check if i have enough slack?

[GerryO]

No harm in doing the Redline now and the TPS output voltage should be checked. The specs are all in the FSM and chances are good that your cables are OK.

[unlimited]

As soon as you said that I went and put it in X]. Had to take my dad to work so gave me an opportunity to use it. Starting the car up the car actually idled at 950rpm, where it used to be at in park so I was about to come back and say "well it's fine now" but after dropping my dad off, I came back home and I put the car in park and it was back up to 1500rpm. Guess I'll keep waiting and see if it goes back to normal. Wouldn't mind help though X]
Modified by unlimited at 12:25 AM 6/27/2009

[alex61089]

That definitely sounds like a tps issue i was having. The a** who had my car before put only one screw in the TPS to hold it in place (it needs two) so it was moving. I've been saying i was going to make a thread on how to do it but im such a lazy mofo. So i'll do it now to show you.

On another note.....

Let me start off with saying... PCV valves are $@$%@%@%@%@!!!! 5 Hours.

I couldnt get the drivers side hose off so i cut it off and went to pepboys and bought a pvc hose that you can cut to fit. the other side however has such a weird shape to it.. is there somewhere i can buy t he PCV hoses for the J at?

So i changed my:engine coolant temp sensorPCV valvesOxygen sensors

It seems as though i got a better pick up but something is still holding it back though. but it does drive better. From my estimates right now I'm getting around 15mpg (lots of stop lights) so im looking for ways to improve it.

While we are on the subject of oxygen sensors.. did anyone have a problem with the passengers side one? the dang transmission wouldnt let me fit the O2 socket over the sensor so i had to use an adjustable wrench to get it out (talk about a pain in the a**)