5.0 Engine Temperature Problem

[ChrisB.]

Hello,

I have my Roadster in "gokart" configuration and while driving around listening for any abnormal sound/vibes/chafing etc. I’ve heard after firing coming out of left side exhaust pipe which leads me to believe that left bank is running rich. In effort to verify this condition I did following:
Checked O2 sensors – good (new pair)
Checked O2 sensors harness (continuity check ok)
Checked continuity of O2 sensor wiring (both sides) all the way to the computer connector – ok
Checked O2 sensors voltage present at the computer connector – ok
Checked continuity of ground wires to the O2 sensors heat elements – ok
Checked power to O2 sensors heat elements – it showed 0v I believe that my fusible link is shot or disconnected. ( from what I was told not functioning heaters of O2 sensors would slightly affect performance and not necessarily create problem I have)
Checked temperatures of the exhaust pipes at the “J” pipe flange:
driver side was around 109 degrees
passenger side 185 degrees (actually pipe is starting to get some gold tint)
I replaced computer with new one since previous owner damaged computer while trying to pull codes. (malfunction light did not work)
I guess my next step would be to measure temps of the driver side exhaust manifold (each pipe) looking for cool cylinder hoping that fuel injector is shot and pumping extra fuel?
Did anyone have this problem before? Help is greatly appreciated - this thing is driving me crazy.
My donor car was 1992 Mustang GT
I installed new FFR Chassis Harness and original engine harness.
I should add that my engine temperature is fine and around 180 degrees and emission system was deleted (air pump and EGR valve)

[Jeff Kleiner]

By "after firing" do you mean popping or backfiring through the sidepipe? Two things if this is occuring under closed throttle decelleration; this can be caused by an upstream exhaust leak such as at the header gasket or sidepipe flange. Secondly, the OEM A9L ECU is set up to go to a very lean mixture under closed throttle coast down for emissions purposes which leads to popping on decelleration.

Although it should not be contributing to the condition you are asking about if you haven't spoofed the ECU into thinking that the EGR is still in place and functioning you need to do so either by using an EGR eliminator plug available through the aftermarket or by making your own with a couple bucks worth of resistors.



If you do not do this it believes that the EGR has failed and will add fuel and pull out timing which is not good for driveability or performance. You can also add resistors in place of the TAB and TAD ("air pump") solenoids so that it doesn't throw codes and trigger a malfunction indicator light (a code on these won't affect performance however)

Good luck,
Jeff

[Walt]

Hey Jeff, if we have the rf harness without the wiring for egr how would we do this?
Thanks
Walt

[ChrisB.]

Jeff,

Thank You Very Much for quick response to my posting, I failed to mention that I installed EGR resistors just as shown in drawing you posted, also after firing (pooping in exhaust pipe only on left side) happens just as accelerator pedal is pressed while in transition from idle to higher rpm and than during gear change while accelerating, another thing is that engine is idling rough until warms up and than stabilizes around 900 rpm.
Would problem with EGR deletion (if I screwed up while soldering resistors) create rich condition only on one side of the engine? and would you know how hot should the stainless pipes be at the point where they go thru opening in the body?

Again Thank You Very Much for responding.

[rmiller64]

Just a thought Chris Have you checked firing order on the left bank? Don't have 7 & 8 crossed