Running like crap! Pulled codes. Got parts coming, but are they the right ones =)

[Nickerz]

Ok, so I just picked up a project car. It's pretty hard to start initially, but once it's started it restarts fine. So my first set of parts that are coming is a
Walbro 255lph kit
Kirban AFPR
Now the second more major problem is major hesitation and bucking above 2000 rpms under load. It revs fine once it's warmed up, but no dice on the road. So I pulled the codes and got these codes

13 Couldn't find any information on this code really as to causes
33 EVP\EGR
91 Running lean

I have not tested the TPS sensor yet, but my thoughts are later this week to test the TPS. Besides that im thinking I should pick up a set of new O2 sensors, the EGR bypass circuit.

The speedo also does not work, I don't know if this would affect the code 13. Any help would be appreciated!

 

[Mustang5L5]

DO NOT bypass the EGR. It will cause more problems due to running lean at part throttle.


Instead, FIX the EGR so it functions properly.

 

[Mustang5L5]

Code 13

13 (O) ISC did not respond properly (extends to touch throttle then retracts for KOEO) -
(R) Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too high)
(M) ISC sticking, open ITS circuit or TP sticking




Code 33

33 ALL - (O, M) EGR did not open/ respond during test or if memory code, did not open intermittently -


Code 91

91 (R, M) System running lean -



Two of those code could be EGR related. Get it working properly. Take the EGR off and clean the plunger. Then depress the plunger and place your finger tip over the vacuum port and release the plunger. The plunger should stay in until you release your finger indicating that the bladder is intact and will hold vacuum. You may need to trace out your vacuum lines and make sure none are broken.

As for code 13, take the ISC off and clean it as well. Then replace it and perform the idle reset procedure. Unplug it and start the car and use the idle adjustment screw to set the low idle speed. Then reset the computer and plug it idle speec control back in and restart. Turn on all the accessories for 2 minutes then shut them off. The car should learn idle strategy over the next few restarts. Do this after cleaning the EGR and ISC and then see if any codes come back.

 

[Nickerz]

thanks for the help, im going to check that out later this week. Hey aren't you an LS1 guy? It thought you had the red TA in that **** right? Or is this another **** guy =)

 

[Mustang5L5]

Lol, no not a T/A. I had a lincoln Mark 8. Click the link and you'll see what that's all about

 

[1990Coupe]

mustang5l5 what happens when your EGR has no vac lines cause the smog pump and everything was removed. it's not going to function properly, in this case can you just take the EGR out and put some kind of plate in its place??

 

[Nickerz]

I picked up an idea from another thread. Since the 91 code is a left bank specific code, im going to try and switch the 02 sensors. If the code switches sides, then I know I at least need a new 02 sensor on at least one side. If that doesn't work im going to use a rebuild kit on all the injectors. If it doesn't work , im going to run a cylinder balance test and see what cylinders on the left bank are having trouble. Then replace the injectors. That will solve the big issue im having. Im sure I will still have the EGR codes, but at least Ill be able to do a freaking burnout. It's just depressing right now!

 

[Mustang5L5]

mustang5l5 what happens when your EGR has no vac lines cause the smog pump and everything was removed. it's not going to function properly, in this case can you just take the EGR out and put some kind of plate in its place??

Well the way the EGR works is that it pumps in air that has already been burned through a previous cycle during part throttle cruising. This is to save fuel economy as less air to burn means less fuel to pump in. So the computer cuts back on the fuel mixture thinking it has some inert air present.

The EGR does not function at WOT or idle, so it has no bearing on HP increase at all.

When you eliminate the EGR by blocking it off, the inert air is now replaced with burnable fresh air. However, the computer doesn't know this and still cuts back it's fuel mixture at part throttle. You will have part throttle lean condition like when you are just rolling through the gears lightly on the throttle.

The proper way to eliminate the EGR includes a tunr to compensate the fuel mixture. Since not many people do this, there are a lot of lean-running Mustangs out there.

Seriously....most of the smog stuff people remove have ZERO inpact in HP numbers. I know it's cluttering the engine bay, but unless you have some understanding of what you are removing and how it will impact the engine, you should leave it all alone

 

[1990Coupe]

Well the way the EGR works is that it pumps in air that has already been burned through a previous cycle during part throttle cruising. This is to save fuel economy as less air to burn means less fuel to pump in. So the computer cuts back on the fuel mixture thinking it has some inert air present.

The EGR does not function at WOT or idle, so it has no bearing on HP increase at all.

When you eliminate the EGR by blocking it off, the inert air is now replaced with burnable fresh air. However, the computer doesn't know this and still cuts back it's fuel mixture at part throttle. You will have part throttle lean condition like when you are just rolling through the gears lightly on the throttle.

The proper way to eliminate the EGR includes a tunr to compensate the fuel mixture. Since not many people do this, there are a lot of lean-running Mustangs out there.

Seriously....most of the smog stuff people remove have ZERO inpact in HP numbers. I know it's cluttering the engine bay, but unless you have some understanding of what you are removing and how it will impact the engine, you should leave it all alone

I realize that removing the smog has no impact on HP. However mine was removed when i purchased my car. It was a 4-8 conversion. I have HCI and No tune, and i read that with HCI you normally do not need a tune, but in my case i think what im going to do it remove the EGR and when i put her on the Dyno they can tune out the EGR and turn it off in computer. Is this the correct way to remove it? PS sorry for the highjack and thankyou mustang5l5 for the information!

 

[AnthonyR23]

it is my understanding that the egr is separate from the smog pump... so why wouldn't you guys just leave it on... doesn't take up much space... just has a vacuum line going to a little solenoid.. than another little vacuum line going to the valve... I really would just save the hassall and keep it on.

 

[1990Coupe]

it is my understanding that the egr is separate from the smog pump... so why wouldn't you guys just leave it on... doesn't take up much space... just has a vacuum line going to a little solenoid.. than another little vacuum line going to the valve... I really would just save the hassall and keep it on.

in my case the vac line is gone, and most of that stuff has been removed already. so i was just going to pull the whole thing off considering i want to have a tune anyways

 

[Nickerz]

I just wanted to let everyone know I fixed it last week. It was in fact the fuel pump. Listen to a stock fuel pump and then listen to yours! I never had a 5oh before so I didn't know what the stocker sounded like. Well it sure didn't werr like mine. It buzzed! So we put the walbro in and it fired right up. Now I got to solve the other big problem, it being so freaking slow!