How did I get rich?

[iLkYsPoNy]

Okay, this will be a long one, starting out with my mods....

-TFS Track Heat Top end kit
- TFS Stage 2 cam
- FRPP 24# injectors
- BBK 75mm t-body
- Summit 75mm MAF
- 255lph fuel pump
- FPR

At first, the vehicle wouldn't stay running. It would start, but as soon as the gas was touched it would stall. I was advised my next step was to get a tune before it would run right ( contrary to Jrichker's belief that is was mechanical ). Well, we changed out the the MAF and put it back to stock. Atleast then it would run, although it ran like hell and ran very rich. Got it to the dyno... they got it started with the new MAF, after a quick tweek.

Put down some good numbers, got the idle to where it was supposed to be, A/F ratio was good across the band, everything was well. That was until they unhooked everything and I was driving home. She pulled hard but the idle stayed at like 1500 rpm. I didn't think anything of it so I kept driving home. Stopped after abour 15 miles, shut her down, and she would start back up. Took about 1 1/2 hours and it started back up in a cloud of smoke ( flooded )....

okay... this is getting too long.... long story short...

Changed the TFI Module ( per dyno shop ).... didn't fix it.
Got a new/used A9L ( per dyno shop ).... didn't fix it.

The whole time it's running pig rich, not consistantly starting because of which. The dyno shop is insisting it's electrical at this point. They say the the oxygen sensor wiring harness "doesn't look good". On the laptop is was showing the oxygen sensors are being unresponsive. My point was, the harness HASN'T been touched, so if it's a problem now, it should've been a problem before, right?

Could it be an issue with the actual correct amount of fuel, but a problem with the t-body not supplying a correct amount of air? Reasoning behind this question is because I got a pretty pronounced whistle from it on the dyno, but nothing now.

Now we're back at step 1 with no idea what step 2 should be. Anyone have this issue before?

 

[91lxttrim]

I know this has probably already been addressed but... Is the MAF calibrated for the injectors?

 

[iLkYsPoNy]

Yes sir, it's been calibrated from the factory for 24# injectors and they supposedly double checked it at the dyno shop.

 

[vristang]

Have you pulled the codes???

 

[iLkYsPoNy]

I just called down to the shop, the other day they couldn't pull codes because the computer was bad. Now I asked then to pull the codes now that it's a fresh computer.

 

[iLkYsPoNy]

Glad the peeps over at the Corral were willing to atleast attempt at helping me...

 

[vristang]

My advice...

PULL THE CODES.

Changed the TFI Module ( per dyno shop ).... didn't fix it.
Got a new/used A9L ( per dyno shop ).... didn't fix it.

Do you still trust these shops?
They have had you spend $$$ on non-issues...


I don't like pissing in the wind, so start by pulling the codes.
If you want to keep spending money on guesses, then feel free


jason

 

[getusummm]

If I remember correctly, you must have the safety switches on the transmission in order to pull the codes. If any are bypassed or disconnected, or otherwise not working properly, you cant pull the codes.

 

[iLkYsPoNy]

As far as trust.... i'm not so sure. I gave them 3 hours of diag. time to figure the problem ( $53 an hour ). If they can't figure it out in that time I will decide my trust factor then.

The transmission is manual... I'm not sure if there are any sensors on it?

I told 'em to pull the codes... who knows if they did or not... I should... but I don't

 

[jrichker]

If I remember correctly, you must have the safety switches on the transmission in order to pull the codes. If any are bypassed or disconnected, or otherwise not working properly, you cant pull the codes.

This only affects the ablity to dump the engine running codes. If there are problems with the switches or operator, you get a code 67 when you dump the codes with the engine off. Operator problems like clutch not depressed, transmission in gear or A/C on cause a code 67 when you dump the codes.

 

[2002BLGT]

fill in the blanks

fuel pressure at idle with vacuum on -
fuel pressure at idle with vac off and plugged -
base timing ( pill out) -
TPS voltage -
when it does idle what RPM -
no readings on the 02s will cause some major problems I would pull the O2 harness out and check it with an ohm meter and replace the O2s if it checks out good

have you tried putting the 19lbs injectors and stock mass air on the car yet ?

is there a chip in the computer ?

 

[iLkYsPoNy]

Fuel pressure at idle with vacuum on - 39-40PSI
Fuel pressure at idle with vac off and plugged - 34-35PSI
Base timing ( pill out) - Not quite sure...
TPS voltage - approx. .91
When it does idle what RPM - Surges ( 400-2000 rpms ) , when not surging ( 1400-170 rpms )

No readings on the 02s will cause some major problems I would pull the O2 harness out and check it with an ohm meter and replace the O2s if it checks out good

Have you tried putting the 19lbs injectors and stock mass air on the car yet ? Haven't tried 19# injectors, but have tried the stock MAF.

Is there a chip in the computer ? Didn't make a difference between the chip being in and the chip not being in.

 

[jrichker]

More Fill in the Blanks:

What is the vacuum when the engine can be made to run at a steady 1200 RPM?

Testing the O2 sensors
Measuring the O2 sensor voltage at the computer will give you a good idea of how well they are working. You'll have to pull the passenger side kick panel off to gain access to the computer connector. Remove the plastic wiring cover to get to the back side of the wiring. Use a safety pin or paper clip to probe the connections from the rear. The computer pins are 29 (LH O2 with a dark green/pink wire) and 43 (RH O2 with a dark blue/pink wire). Use the ground next to the computer to ground the voltmeter.

Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter. Do not attempt to measure the resistance of the O2 sensors, it may damage them.

Testing the O2 sensor wiring harness
Most of the common multimeters have a resistance scale. Be sure the O2 sensors are disconnected and measure the resistance from the O2 sensor body harness to the pins on the computer.

The O2 sensor ground (orange wire with a ring terminal on it) is in the wiring harness for the fuel injection wiring. I grounded mine to one of the intake manifold bolts

Replace the O2 sensors in pairs if replacement is indicated. If one is weak or bad, the other one probably isn't far behind.

 

[iLkYsPoNy]

Man I wish some of you gurus on here could call and talk to the shop where my car is....

Jrichker, I will try and find that information out for you.

 

[iLkYsPoNy]

i dont know if it will make a difference or not.... but i forgot to mention it was back firing through the intake when it was trying to start the other night ( post new A9L ).


EDIT: i think this happened before they adjusted timing

 

[jrichker]

Backfiring out the intake is either a valve stuck open or a lean mixture or spark plug wire(s) connected to the wrong cylinder(s). Check compression on all cylinders and then look for vacuum hoses loose, cracked, or misconnected. Check the line for the vapor recirculation system – it is easy to knock loose and not see it when you connect the air pump plumbing. If the vacuum line for the EGR valve and the air pump are cross connected, some very strange things can happen. Check the mass air flow electrical connection and see that it is tight, the same goes for the fuel injection wiring harness connectors up on top of the manifold near the firewall.

Sticking valves: If a intake valve is bent, has a bad spring or is misadjusted, the engine will sometimes backfire through the intake. Use a vacuum gauge connected to any convenient spot on the intake manifold. Run the engine at 1000 RPM & look for 18-21 inches of vacuum with a steady needle. A problem intake valve will make the vacuum gauge needle sweep 5-10 inches.

Lean fuel mixture breaks out into several sub categories:
A.). Vacuum leaks
B.) Air entering the intake without passing through the MAF.
C.) Failure of the MAF, BAP/MAP (Baro or Manifold Air Pressure, same sensor, different name), ACT (air charge temp), or ECT (engine coolant temp). These should set a code in the computer.
D.) Leaking exhaust gases from EGR valve at WOT or EGR opening when it should not be open.
E.) Poor fuel delivery due to bad fuel pump, clogged filter or bad fuel pump wiring. Look for low pressure or fluctuating pressure. Standard injector pressure is 39 PSI at idle, with the vacuum line disconnected from the regulator and capped.
F.) Clogged fuel injectors.- see the cylinder balance test below
H.) Fuel injector wiring problems causing injector not to deliver rated flow.
I.) Computer problems: (computer problems are not common like sensor problems)
J.). ROM has bad data in fuel or timing table. This should also set a code in the computer.
K.) Failure of one or more of the computer's driver transistors for the fuel injectors. No code set on this one. Use a noid test light to test the injector wiring & injector drivers,
L.) MAF calibration off or mismatched to injectors.
M.) ACT or ECT bad. Sometimes the sensors will be off calibration, but not bad enough to set a code. If they falsely read too high a temp, the engine will back off fuel delivery.

Cylinder balance test:
Warm the car's engine up to normal operating temperature. Use a jumper wire or paper clip to put the computer into test mode. Start the engine and let it go through the normal diagnostic tests, then quickly press the throttle to the floor. The engine RPM should exceed 2500 RPM's for a brief second. The engine RPM's will increase to about 1450-1600 RPM and hold steady. The engine will shut off power to each injector, one at a time. When it has sequenced through all 8 injectors, it will flash 9 for everything OK, or the number of the failing cylinder such as 2 for cylinder #2. Quickly pressing the throttle again up to 2500 RPM’s will cause the test to re-run with smaller qualifying figures. Do it a third time, and if the same cylinder shows up, the cylinder is weak and isn’t putting out power like it should. See the Chilton’s Shop manual for the complete test procedure