Idle at 1500rpm,very bad throttle responce, very rough, stuttering. I SEARCHED!!

[redsx13]

Hi, I recently swapped in a red top SR. Upon start up it was found to have some trouble running. Like the post says, i did SEARCH, but i was unable to come up with any answers for the unique problems i am having.

to the best of my abilities i will give you guys a brief rundown of the issues the car is having.

1.fluctuating idle- starts out around 2000 rpm's and then drops down to about 600 rpm's during normal running temp. but sometimes the rpm's will just stay at 1500 and not drop down at all. The idle speed has a mind of its own

2. very rough- when the motor is at lower rpms (500-1000 rpm's) it shakes quite a bit, it even feels like it may die. airflow out of the tail pipe is also inconsistent.

here is the weird part-

3. Strange throttle response- when the throttle is momentarily depressed (to about 1/4 of the way down) car will bog, rpm's will go down for a second, but then it will rev up just fine. (car will rev all the way to red line.)

4. After the car is revved up, the idle will bounce around for a bit, idle will go down 400, come back to 1500, go down to 500, back up to 1000 and so forth. before finally leveling off.

5.The car smells strongly of fumes- so much so that it makes it undriveable, im not kidding! (may just be an exhaust leak, or culd be running rich)

6. very low boost- reading about 1-2 psi of boost. (may be an exhaust leak/ mis-adjusted bov)

here are a list of parts that came in the clip, and installed on the motor when i got it.

-maf (i think it is from an older skyline)-larger injectors (unsure of cc or brand)-s14 turbo-ecu retune (new PROM chip)

here is a list of what i have installed that may affect motor-NGK plugs (checked gap)-greddy fmic (type RS)-greddy hot pipe and RS BOV (i need help to tune bov)

As for the vacuum lines,



Please help me!

i just need some ideas and how to check them

-TPS?-Timing?-vacuum lines?-Maf?-running lean/ rich?-IACV?


Modified by redsx13 at 12:08 AM 8/23/2008

[blinker_fluid]

possible problems...

1. Maf not wired correctly2. ecu not tuned for maf and/or injectors3. vaccum leak

i would check these first along with the other things you've listed. Try pulling the codes from the ecu to see if anything pops up. Make sure all spark plugs are firing along with the injectors.

[redsx13]

1. Maf not wired correctly

Possible, but i wired it up exactly the way it was on the clip. and when you pull the plug off the maf, you can really feel the difference. (how can i check wiring?)

2. ecu not tuned for maf and/or injectors

Also possible, but would it really car to idle that high? and thats the way the clip came. and i highly doubt someone did a upgraded injector swap after the car was chopped in half.

vaccum leak

i have triple checked all hoses that i know of (there are not that many)

Make sure all spark plugs are firing along with the injectors.

all injectors are firing, not sure about plugs yet, I feel so bad starting this engine, it sounds like its hateing life!

i diddnt know it was possable to check codes on an SR for some reason(i know the ecu can, but i thought the swap rendered that feature useless)i will check codes and let you know

[redsx13]

just checked codes....

only one i got was a 13- coolent temp sensor

i cleared the codes and started the car again, now all i am gitting is a 55(all ok)


Modified by redsx13 at 8:31 PM 8/17/2008

[duffman1278]

Sounds like a boost leak to me, run a DIY boost leak tester, its very simple and will save you a bunch of headaches.

Also, it could be that the ECU isn't tuned for it. To check that, you'd have to have a shop with a dyno test that out. I had the same problem. This shop told me in order for them to check what was on the ECU, they'd have to check it on the dyno.

[jr_ss]

Sounds like a bad MAF to me. You said you unplugged it and it ran better? Did the idling smooth out?

You need to get a FSM... Heavythrottle sells them, or I might be able to transfer the files from my disc to the comp then send them to you if you want...

[heavythrottle]

Check the throttle stop screw - make sure it is closing 100%.

Also check for spark in all 4 cyls - SR runs surprisingly well on 3 cyls.

[blinker_fluid]

just checked codes....

only one i got was a 13- collent temp sensor

The cts can cause the high idle problem, as for the maf you should try cleaning it with CRC maf spray and check the wiring against heavythrottle's diagram http://www.srownersclub.com/faq/faq_mafs.asp. While your looking at the harness get a multi-meter and check the wires, black=ground, black/white=12v with the ignition on, white= somewhere around 1v with the engine running at a normal idle higher rpms gives higher voltage.

[Koshin]

The cts can cause the high idle problem, as for the maf you should try cleaning it with CRC maf spray and check the wiring against heavythrottle's diagram http://www.srownersclub.com/faq/faq_mafs.asp. While your looking at the harness get a multi-meter and check the wires, black=ground, black/white=12v with the ignition on, white= somewhere around 1v with the engine running at a normal idle higher rpms gives higher voltage.

+1

[redsx13]

Sounds like a bad MAF to me. You said you unplugged it and it ran better? Did the idling smooth out?

no, it ran worse. but still had all the same problems it did with the maf plugged in.

[redsx13]

Check the throttle stop screw - make sure it is closing 100%.

Also check for spark in all 4 cyls - SR runs surprisingly well on 3 cyls.

like the diagram above shows, the throttle is closing 100%.

it is running on all 4 cyls.

[redsx13]

Sounds like a boost leak to me, run a DIY boost leak tester, its very simple and will save you a bunch of headaches.

Also, it could be that the ECU isn't tuned for it. To check that, you'd have to have a shop with a dyno test that out. I had the same problem. This shop told me in order for them to check what was on the ECU, they'd have to check it on the dyno.

how do i check for a boost leak? let me know how, and i can make a boost leak tester. Btw, the car is very bare (no front bumper, relocated fuse boxes, no a/c, repainted bay)only the necessary stuff to get it started. so i can see all the fmic piping and connections; they all look fine.

I am also worried that the ECU may not be tuned to the car, but thats the ECU the car came with.(i opened the ecu up and it has a chip), shouldn't it run correctly??? In this condition, the car isnt even drivable, so how was it driving in Japan??

[redsx13]

********UPDATE********

While testing some of the ideas mentioned above, I left the car running for awhile, and idle did drop down to around 600-700 rpms. at this point the car sunded like it was going to die, but miracuously i diddnt. it was stuttering very badly. This may no longer be an idle issue.

i will keep checking the rest of your guys ideas, and update you on my findings frequently.but for the mean time keep thoes ideas coming! you guys are very helpful. thankyou!

[redsx13]

The cts can cause the high idle problem, as for the maf you should try cleaning it with CRC maf spray and check the wiring against heavythrottle's diagram http://www.srownersclub.com/faq/faq_mafs.asp. While your looking at the harness get a multi-meter and check the wires, black=ground, black/white=12v with the ignition on, white= somewhere around 1v with the engine running at a normal idle higher rpms gives higher voltage.

while trying to fallow the diagram i noticed that my maf is not like the one from a z32 like the one pictured.

here is a pic of my maf (it used to have a connection piece with four holes that connected it to air box/filter, but that piece has been removed.

sorry for the cell phone pic
Modified by redsx13 at 11:17 PM 8/17/2008

[redsx13]

come on, someone knows what kind of maf this is.

[blinker_fluid]

need a better pic of the sticker

[redsx13]

Just found out that the motor was an automatic, tharefor it has a different tps than the manual. Does it sound like a TPS could cause this problem? Is there any wiring involved to adapt the auto tps to a manual? If so, whoever did the 5 speed swap may have screwed it up and that may be my problem.
Modified by redsx13 at 11:34 PM 8/20/2008

[SpeedRacer1]

No thats not the issue. I have run an auto harness on my car for 6 years now.

That MAFS is NOT a Z32 MAFS, off the top of my head I want to say its early 90's Skyline Non-GTR or Maxima but I cant remember for sure. It sounds like your main problem is the ECU tuning for the MAFS, MAFS wiring, or MAFS itself.

[nzmoman]

what are the last three numbers on the code for that MAF?...

also make sure of a few things...

maf is flowing the correct direction,

there is no open port blowing air near your throttle or your IC piping. There is usually a large port on the cold pipe of FMIC kits that needs to be capped off.

and make sure that the vacuum line for your idle air system is connected somewhere before the throttle, but after the MAF. (usually a port on the FMIC also for this.)

if you can provide an overall picture of your engine bay. there are guys on here who can find a needle in a haystack, but a picture of a throttle won't do. Show us the actual throttle with all the lines connected before you go running to buy a new MAF or ECU. I think it sounds more like a boost because at idle MAF's are not working that hard and you did not say you were blowing smoke, (everytime I have seen the wrong MAF I have seen black smoke and stuttering)

[SpeedRacer1]

The green tag should be 22680-02U00, its a skyline MAFS not proper for your setup. If the ECU was retuned for a Z32 MAFS then get a Z32 MAFS. Part number 22680-30P00, orangish sticker. If it was tuned for stock get a stock MAFS.

[redsx13]

what are the last three numbers on the code for that MAF?...

also make sure of a few things...

maf is flowing the correct direction,

there is no open port blowing air near your throttle or your IC piping. There is usually a large port on the cold pipe of FMIC kits that needs to be capped off.

and make sure that the vacuum line for your idle air system is connected somewhere before the throttle, but after the MAF. (usually a port on the FMIC also for this.)

if you can provide an overall picture of your engine bay. there are guys on here who can find a needle in a haystack, but a picture of a throttle won't do. Show us the actual throttle with all the lines connected before you go running to buy a new MAF or ECU. I think it sounds more like a boost because at idle MAF's are not working that hard and you did not say you were blowing smoke, (everytime I have seen the wrong MAF I have seen black smoke and stuttering)

Im really starting to think that its the maf. As for the type of maf, the shop i bought it from says it is from a skyline.

maf is flowing in the proper direction, hole for stock bov on fmic is pluged,idle air hose is connected, i can get some pics of the engine bay tomarrow, but better yet, i will get you guys a video.

[redsx13]

*****update*****

I have just updated the my main description of the problem. I also added some helpful info.

[Hijacker]

After all this, you haven't verified if the ECU was tuned for that MAF or for a Z MAF. I'm in agreeance with Speed that your MAF is the culprit.

[redsx13]

After all this, you haven't verified if the ECU was tuned for that MAF or for a Z MAF. I'm in agreeance with Speed that your MAF is the culprit.

O, sry . i thought it was implied... Just to clairfy, I have not changed out any parts that would effect engine preformance. the only exeptions are the spark plugs, fmic, bov, and clutch. *I assume* that the ecu has been tuned for the skyline maf, larger injectors,and s14 turbo. because those parts came installed on the car.

[redsx13]

As for the roughness, no pinging, no exessive smoke, but it will bogg for a second when you give it some gas. other than that, it runs fine in the high rpms. If i had to describe the roughness at idle, it feels just like a sparkplug wire or injector is unplugged. but all the cylinders are firing.

Here are some things i have tried recently.

I was thinking it was timing, so i loosened the CAS and turned it w/o removing it. only thing that did was raise the idle up and down, but it still had the same roughness. then I was thinking TPS, so i unplugged it nothing happend, the car didnt run any different, even when the motor is revved up. (is that correct??) Then i was thinking 02 sensor, so i unplugged that and again, nothing happened (is that also correct??) this may be an unrelated problem, but i also have really really low boost (around 1-2 psi) and it smells like its running rich.

Someone back me up and tell me that it's true that unpluggng both the o2 sensor and tps should cause a noticable change in running condition!!!!

I am desperate!!! Tetsudatte kudasai!!!

[redsx13]

***Update***

I just ended up bringing it to a shop. 2 days later the shop calls me to tell me the car is fixed and to pick it up. When i go to pick it up that afternoon, I dont recignize my own 240, why?, because my whole roof and hood are smashed in!!!!!!!!!!!! What do they say..... It looked like this when you brought it to us. WWWWTTTTTFFFFF!!!! After a closeer inspection, the damage resulted because SOMEONE forgot to put the hood pins back on when they took it for a test drive.

O... and you know how they said that they fixed the idle problem. thay diddnt!!!!!

They had an inshurance agent come out to look at the damage, and the agent tells them that the hood had been like that for a while because there was rust on the hood whare the paint had come off. I diddnt see the rust he was talking about, but that guy is wrong!!! that insurance agent should be fired!!!

What do i do??

[Tulsa_S-13]

Oh bummer, that's a crappy situation.

Sounds like whatever shop you took it to is completely incompetent. It also sounds like they probably tuned it for a Z32 MAF as mentioned before.

Get your car out of there as soon as possible. I'm sure someone on here can point you to a shop thats local to that area.

[Hijacker]

Your options are to eithera) threaten them with legal action. People tend to fold pretty quick when the words "my lawyer will be in touch soon" get thrown around.

b) get a lawyer involved. You won't come out ahead as legal fees are likely to eat up anything you could actually make. At least you'd have satisfaction for sticking it to an @sshole.

c) have your insurance pay for the damage. If you call it in to your insurance agency, and explain to your agent or claims adjuster that you didn't do this damage, and that the shop that did it is trying to pin it on you, they will likely talk to the shop's insurance agency and hopefully force them to pay for it.

Either or, get someone official involved quick. After so long, it becomes harder and harder to pin the blame on the real culprit. Also, take pictures. Lots of them. Make sure you get good shots of the exposed metal before it rusts. That's your real proof that you didn't do the damage. Surface rust starts to form pretty quickly depending on your area, and the condition of the metal, but deep seated rust is the real proof. If it's there, then they can claim you did it. If it isn't, then it's pretty obvious that damage wasn't done by you.

[nzmoman]

Call an attorney and do not pass go. Most shops can't afford legal battles and a good attorney will be able to get you enough to cover more than your car and get enough to be able to pad his own pockets, while keeping the shop accountable.

[boro drift]

Yeah, don't drag your heels bro, take legal action immediatly. Sorry to hear about your car, I would have went berzerk.