Tuning Questions "need your help"

[Danster]

Yesterday I went through the "spring Cleaning" guide from gnttype.org site and I also did the top engine cleaning procedure. I also installed the SC2 that arrived yesterday. The spring cleaning was completed first minus the differential then last was the top engine cleaning. It ran rough afterwards, I then realized I needed this morning to check the plugs, sure enough their were filthy, I celaned them and re-gap the plugs and reinstalled. Idles much better. I then proceeded with the IAC and TPS adjustments. The problem I'm having after setting the RPM's to 500 +/- 50, it seems to run rough, as it almost wants to die and sometimes it does. It I press on pedal to rev up a little it seems to run much better. I have not changed the O2 sensor, should I change it out and if so with which one, a heated or non heated one?

Can someone tell me what else I might need to check in order to get a good idle without hesitation. The only mods to the car are a K&N filter and a chip (kenne Bell 900643).

Thanks in advance!

Dannyo

 

[RobV6]

Usually our cars don't idle well when cold. You didn't state what injectors, fuel pressure. However, the kenne bell chip might have some thing to do with it. Just quessing.

Also once it's warm does it do the same?
As for the heated and non heated 02 sensor.

I been using non. And yes it it's great till it warms up.
Heated ones , I couldn't tell you.

HTH'ed

 

[Danster]

I can't say about the fuel pressure as I'm waiting for the one I ordered. But it is the stock FPR so no adjustments can be done, correct?

Where can I go to see what my readings should be at idle? Again, I only have an SC2 for tuning.


Dannyo

 

[Danster]

I forgot about the injectors, should be stock. How do you indentify the injectors, part number, color, etc?

Dannyo

 

[Steve Wood]

were you setting iac by the instructions on Gnttype.org?

Did you plug the iac back in after the adjustment?

Do you have a scan tool?

 

[Danster]

The IAC was adjusted by the instructions from gnttype.org. The IAC was plugged in after the settings. I have a scanmaster2.


Dannyo

 

[Steve Wood]

okay, that makes it easier.

First, put in a new set of plugs. Top Cleaning does not do the old ones any good as you discovered.

Then, drive the car until it is fully warm. Then put it in Park, A/C, off, engine idling and look at the iac counts on your SM. They should be in a range somewhere around 15-40. Different cars idle a bit differently but 20-25 should give you a pretty good idle.

If the counts are higher, turn the iac screw in (clockwise) to reduce them. If the counts are too low, back the screw out (counterclockwise) to increase the counts. Move the screw about a half a turn at a time and check the counts.

Note, that turning the screw in to lower the counts will raise the tps voltage so you need to keep checking it each time you adjust the iac screw as well. You must readjust the tps to keep it less than .46 if it starts to go higher than that number. Backing the screw out is seldom a problem as the tps can go much lower and not have any effect.

When you get it into range, kill the engine and restart it to reset the iac and insure that it is still where you want it.

Hopefully that should fix the problem.

 

[Danster]

Here's what happened so far. I took the car for quick spin, was still idling a little rough. Depressed the throttle about 1/2 way and she took off pretty good for a couple of seconds then we had a backfire through the exhaust and afterwards I couldn't give much throttle beyond idling and the car wanted to die out. So cruised it home no more than 25 mph.

When I got home I preceded to check the plugs again and one of the wired detached from the boot (I tried pulling the boot not the wire) so I went to the auto parts to purchase some wires and an oxygen sensor. I changed both items and it still idles extremely rough. I took down the readings from the scanmaster2. Let me know what I need to check or replace

AF - 03
L8 - 28-32
bAt - 13.6
Int - 128
bL - 142
CLt - 162
AtS - 85
r - 550 - 775 (jumping around between the numbers)
tPS - .46
IAC - 37-47
cc - 24-252 (jumping around between the numbers)
no malfunction codes being displayed
O2's - 417-593 (new install)


Can someone help me at what to do next?


Dannyo

 

[Danster]

Update: I rechecked the plugs on the passenger side as I forgot to clean those after the top engine cleaner was inserted. Removed and cleaned the spark plugs. Car idled better, but still rough. I went through the IAC and TPS procedures and when I set the RPM's to 500 the car idels really rough to the point it almost wants to die out.

Another question how do you reaad the VDO vacuum/boost gauge? Reason I'm asking, if I'm correct and left of the 0 mark is vacuum and right is PSI (boost), then I like to know at which point would I start seeing the PSI, at cruising levels 55-75 mph, when you go 1/2, 2/3 throttle, etc? I took the car out again after the above adjustments and tried 1/2 throttle and it started to pull real good but the retard on the scanmaster2 climed immediately. Why? Do I need to adjust boost? How do I adjust the boost, by the actuator? If so, how do you know when you have enough boost?

I have my Walbro fp but it's not hooked yet, waiting for the adj FPR to arrive.

Can you tell me what I need to check for the above problems, thanks again.


Dannyo.

 

[salvageV6]

Left of 0 is vacuum.

If you get KR under load suspect, bad fueling, something hitting for false knock, too much timing in the chip or too much boost.

Get the good pump and a hot wire in the car first before anything else. Get a decent f.pr. gauge you can tune with and make sure it goes up under boost.

TPS should be below .45 car idleing foot off the pedal I set mine at .44V.

WOT at or over 4.5V if possible.

 

[Danster]

How can you tell when it's false knock or real knock
What does the vacumm in the VDO mean? Is it used for something?

I will try to install the fuel pump next weekend along with the adj FPR, thanks!


Dannyo

 

[TurboJim]

Your MAF is too low. 3gps is default. Sounds like an IC hose is leaking or something to that effect. Would also explain the backfire.

 

[salvageV6]

Car idleing smoothly in park you should see about 16-20 inches of mercury or vacuum. It should not be moving up and down much you want a steady reading.

Is it? Vacuum is used a lot for tuning drivability problems it will vary at idle with a leak.

Your car probably has a bunch of little problems requiring some tuning.

Join a club and get some TR guru friends, quick.

 

[sixgun86gn]

I would also take a look at that chip.When I first got my GN I was using a KB chip.When I finally got a scanmaster I noticed it would knock a little.And they idle rough anyway.Then I got a MM chip and it was much more responsive.The KB chip is ok but not as good as some of the other chips on the market IMHO.I have the extender and lti MAF now and it is alot better.

 

[Danster]

The vacuum does stay between 16-20 at idle. So I guess it is ok then??

I have ordered a Thrasher chip and should be arriving any day now. I will change the chip after I have installed the Walbro 340 and the adj fpr.

I plan on ordering some new rubber hoses for the IC.

Thanks for the replies. I will update when I have added the other mods, thanks everyone.

Dannyo

 

[RobV6]

Danster.You where given some good advice.

Get the pump,adjustable fp, And use the scanner.

These guys gave you the answer....Now the fun finding the problem. If you want I can look at the stock injectors for you off my 2,400 GN

Sorry I was late in returning.... Trying to get 2 cars ready!!

Good luck E-me if you want. But there are people like Steve Woods who have helped me in same area.

Rob