Need help finding out what to do about this, I posted a ad a few weeks back about removing the smog pump and air tube's from my 90 Iroc. And got the response that nothing would be affected. No service engine light would appear. Now that I have done this, I am getting the light with a code 13 Does anyone know if this is a result of the smog being removed, or if this comes from another problem. I have done every thing I can think of to resolve this with No success. Any help would be greatly appreciated.

 

Sounds like another problem since I've never heard of anyone getting a code from removing the smog pump and/or air tubes. Code 13 is Oxygen (O2) Sensor - signal stays low ("lean") during warm engine cruise. If your O2 sensor has a lot of miles on it, I'd change it, clear the code (disconnect battery for a couple minutes), and see if it comes back. You might have a clogged fuel filter or fuel injectors.

------------------
Greg Westphal
'87 IROC 355TPI/A4

 

Have already replaced 02 sensor with a new bosch unit. And fuel pressure is running a constant 45 pounds at Idle, Raise rpm and fuel pressure drops slightly. at 2000 rpm holding atbout 35 pounds of pressure. And with this I don't know what else to try. ANy more suggestion's would be appreciated

 

Fuel pressure should not drop when RPMs increase. If they do, you have a fuel problem. Either pump or FPR.

 

I have a new holley adjustable regulator, Should I increase the pressure and see what happens

 

I took off my smog pump... got no codes, and you shouldnt either... this is unrelated to that.

I'll try to get back to you on the adj. fuel pressure regualator... set it at 48 to 50 psi with the vacuum hose disconnected to the regulator for now... it does drop when u hook the vacuum line back up


------------------
Jethro
1987 IROC Z 13.92 and 1.92 60' street tires stock engine

 

Ok, I got the pressure set at 50 the pressure drops about 5 Lbs. When you first hit the throttle and jumps right back up.I was told by a guy locally today that I needed to jump out the wire's in the smog system, Or I would keep getting codes. I have never heard that before. Any body ever heard of this. Also I replaced the EGR valve today as a result of more apparent incorrect information. Because that didn't help either

 

Are you sure your MAF Power relay is Functioning and that you did not mess up the wiring anywhere down line? I removed ALL emmisions equipment from my car and NO CODES,,,I still have the stock chip as well....I removed the AIR system, The converter, EGR VAlve, and the charcoal canister...NO codes Id check all of the wiring back to the ecm on that circuit....Ive never heard of JUMPING any of the air system wires...Looking at the diagrams tat would just cause a short..

All my wires are just Unplugged and hidden back inside the main engine harness JUST IN CASE the Government decides to move emmisions testing to my county...

 

This is on my 90 IROC it is map not MAF. I have never heard of jumping the wire's either, but that was a opinion from a local shop. And at this point I'm taking all opinion's. I have been working with an on car's for 15 yr's and I have never ran into this problem with anything. I removed everything from my 87 as well with no prob's. but with this one being map I didn't know if that would make a difference. I don't really know what else to do. I'm going to replace the ECM tomorrow, And see what that does. I have already replaced everything else I can think of and traced down wire's until I'm about ready to ****** the complete system and start fresh. So I welcome any information that may help to resolve this problem.

 

OOPS the MAF thing was a cross over from another post...My bad....BUT the wire thing makes no sense...Ive helped guys with 91,92 delete thier stuff and no problems...The way it was explained to me is that the computer is dumb on the emissions stuff..Since a null value is within the acceptable parameters on the ecm then uplugiing it does not cause a SES light..More than likely you will cause the ses light when making a jumper...and get a different code..

 

If your fuel pressure is dropping at all and not rising several pounds when you go WOT, then you probably need a new fuel pump. The fuel pressure regulator could be bad or the vacuum line to it disconnected or broken, so I'd check those first, but I'm betting there's a Walbro pump in your future.

------------------
Greg Westphal
'87 IROC 355TPI/A4

 

Just wanted to tell everone THANK'S for all the help and advice on this problem. I finally got the problem fixed. I started pulling the wiring harness, And found that a ground wire on the back of the left (driver's) side head was pulled out of the connector. Just so everyone will know there are 2 ground connector's on that side, With 2 wire's in each connector. I thoght most of the ground's was on the other head. And I also thought there was only one wire per connector. But anyway's that was the whole problem. And again THANK'S for all the help.