When I bought my 90 the po said the rough idle was due to bad fuel injectors. But it only did the 600 to 1000 lope after it had warmed up and went into closed loop. Cold it was rock solid.

So I figured it was a bad sensor that did not get used in open loop.
I replaced the IAC, TPS, EGR valve, O2 sensor, distributor cap and rotor, removed and cleaned the throttle body, car would start up fine, then when warmed resume its lope. I also tried the TPS adjustment, but the 90s have an unadjustable tps. I also tried to set the mimimum idle, but after connecting the A and B terminals on the ALDL plug and disconnecting the IAC wires, it would idle at about 1300.

I hooked up my laptop and favorite scan software, all sensor readings were normal, nothing going up and down.

So, I bought a set of 22 pound f*rd fuel injectors off of fiveomotorsport on ebay and put them in.

That was it, runs fine now.

 

Shoulda paid attention to the PO's explanation!

 

Could you educate a guy who is a little slow.....what in hell in a po? I would normally call this a post office!

The stock Multec injectors in 89 - 91 Vetts were crap from the factory as they have the highest failure rate of all brands. No wonder you had a problem with them

 

Previous owner??

 

I learned something new today.....Thanks!!

 

A bad EVAP system with all those leaky garbage vacuum lines caused my car to surge at idle from 1000-400 rpms for about a good 15 minutes. I say take all those lines out and plug the 2 ports on the TB with rubber caps.

 

Mr eliminate it.

 

 

I eliminate problems. Not cause them. The EVAP system notorious for causing vacuum leaks, affecting drivability. The crappy 80s MAF was just another way for GM to sabotage their products so a "rich" person would stall out suddenly. They would end up towing their car to a GM dealership. Of course, it is certain the dealership is gonna make money off them!!! The coolant passing into the TB under the IAC place is useless unless you are living in weather where the temps are below -40 degrees. GM's idea to program the fan to turn on at 226 degrees is just asking for more problems. From that "smart" idea, sure your emissions are gonna be less but in return, you get more pinging, coolant hoses blowing, intake gaskets leaking, etc... No wonder everyone thinks American cars, esp. GM are garbage. The AIR system intermittently lets air into the exhaust system, which screws with the O2 sensor, causing a falsely lean condition. The EGR valve can stick open causing a no start/hard start/random stall condition. GM's leaky Multec injectors were just another way for GM to make money by causing hard starting. Their idea was to make it so customers would end up taking their car to the dealership more frequently so they can make even more $$$$$$$$$. The Opti... Well, I'm laughing because my friend's 93 V6 Grand Am has a slightly higher tech factory distributerless ignition system and a lower failure rate than the Opti.

 

There's another one I've heard a time or two....

PoPo.... What the heck is a PoPo???

Let's use 'PoPo' in a few sentences.............

Do you have the PoPo? (Is it a disease?)
Where's the PoPo? (is it lost?)
Look at that PoPo. (I probably wouldn't know where to look)
The PoPo was on my tail! (Is it a wart or something like that?)
My PoPo isn't worth a dayum. (Wonder if mine is ok?)

PoPo, what a funny word. Uh-Oh, is PoPo a word??????????

 

kopbet you are definitely manic depressive, podna.
I'd reccomend Paxil, Zoloft, Welbutrin or some of the other SSRI medications for ya buddy.
Your world CAN look a LOT better, amigo.

 

What is absolutely amazing, is that GM can get a car, any car, off an assembly line under it's own power with out your sage and devine guidance.You eliminate troublesome systems that you aren't clever enough to fix.

 

Well, who needs these troublesome systems when they can cause problems? Not trying to start anything, but I don't need these problems anywhere in my life. We also do not have any emissions here so I can get away with it.

 

Wouldn't it be easier to just tear out the section of the brain that controls those emotions?
No medication would be needed !

 

If it only was that easy, it probably would have been already done.