a little trouble with idle before and after recent mods

[b00sted87]

spent all weekend manually tuning my cousins hog. i got a new regulator and adjusted it to about 50 lbs. and started the car up. it was extremely lumpy like it had a huge cam, (stock cam by the way). then, it started to blow black smoke like it was running really rich. at idle it was hanging on to not stall. i drove it around the block and when it boosted, it broke up and sputtered while blowing much black smoke at only about half throttle. then i did a boost leak test and the EGR had a huge leak. i then blocked that off and capped all the vaccuum lines and ports on the celenoid. checked the plugs which were black and the #five cylinder didnt have the wire connected. changed all plugs. fresh oil also. this made a huge difference in not braking up but it still idles extremely rough with the check engine light on. when i get into boost a little, the light goes away and when i let out and the car is at coast idle to stop idle the light comes back on. it runs pretty strong to about 50/60mph and then kind of runs out of steam although its holding boost at about 17/18#. i personally think is the MAF. should i go with an ls1 and a translator or get a fresh tune. this is all on 93oct and a 93 chip. anu suggestions?

thanks

cody

 

[onslow]

Hi -

Do you have some sort of diagnostic tool? If so, what are the readings?


Steve

 

[challengermike]

Sounds like 2 problems.First adjust the fuel pressure down to 42 pounds with the vac line off.At 50 it will idle alittle rough.

 

[TURBOV8R]

Agree with Mike,knock the FP down,and check to see what code your getting will set you in the right direction to proceed.When my MAF took a dump code 34 rang up and in gear idled like a machine gun and low vacuum.In park sounded fairly normal but the SES lite came on after 30 seconds.Dig deeper!

 

[b00sted87]

i could understand that, but why s it falling off near top end? also what ddo you mean by a diagnostic tool? like a data logger or just a plug and read?

 

[TURBOV8R]

would say for the moment,find out what code is coming up and that should explain why the lite comes on and off.Check the turbo regal website,they have all the codes and how to ground the ALDL connection as well as areas to check pending on the code.I dont have any type of diagnostic tool 'cept for this forum and a voltmeter, sometimes frustrating but these guys are good people and you learn as you go.

 

[onslow]

i could understand that, but why s it falling off near top end? also what ddo you mean by a diagnostic tool? like a data logger or just a plug and read?

Hi -

I will assume you are not totally familiar with troubleshooting problems with one of these cars...I do not mean to insult you.

To answer your question, there are plug and read, and data loggers. I think plug and read is sufficient for basic maintenance and tuning. Regardless of what you use...

there is a diagnostic port below the left front corner of your center dash section - above your right leg. You should have a Scanmaster, OTC or some other electronic diagnostic tool you can plug into that port to read your car's sensor readings sent thru the car's computer.

Once you have that tool, you can use it to see Error Code numbers and to determine whether your car is running within acceptable limits in terms of the Throttle Position Sensor, Coolant Temperature, Idle Air Control, MAF, etc., etc.

Without using one of these tools, you will mostly guess at what is happening electronically when one of these cars is not running properly. And...you cannot tune one of these cars without one of these diagnostic tools.

Now, what do the numbers from the diagnostic tool mean? You can find out what the Error Code numbers are (and their causes) by searching in the Tech section of the gnttype.org Web site.

You can get the tune specs by searching for the TPS/IAC reset procedure on that site. Print out all this information so you can use it as a manual for your car.

Once you plug in one of the diagnostic tools, you can see the IAC, TPS, BLM, MAF, etc. readings. Then we can help guide you to fix your problem(s). You should also know that this turbobuick site has a tremendous amount of information about troubleshooting specific issues...so, search for more info here too.

Important: After you plug in the tool, you have to wait until the car is in "closed loop" before noting the readings. Your diagnostic tool may or may not tell you when it is in "closed loop." I have an OTC scanner and it does. I do not know if the Scanmasters show it.

"Closed loop" is when the car has warmed up enough for all the sensors to be fully operational and sending accurate readings to the computer. So, if you do not know if it is in closed loop, wait about 5 minutes or so for it to fully warm up.

We will wait for your readings.

Steve