i own a 1988 iroc z 350tpi and as of late my car has been starting hard and has been runnin like there is a choke stuck on but its fuel injected . when i give it a shot of gas wrather than churpin the 245 50r 16's on back it bogs out it is also rollin out some black smoke which is unused gas . I can also be goin along at a certain speed take my foot off the gas and the rpms don't drop it just keeps goin at the same speed until i give it a quick shot of gas then the revs drop down to normal . but i have no clue what it is there is no engine light on so if anyone has any info at all on what this could be please reply to this or emaile at derek_bigger@hotmail.com i will really appreciate all your help and my car is hurtin but it still woops those rustangs whats that tell ya chev rules!!!!!later

 

no codes? then i'd start by making sure the tune up parts are good, check filters etc.

------------------
ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

what do you mean by codes is that when the check engine light comes on?cause if it was a bad sensor wouldn't the check engine light come on because it does seem like the car idles really high

 

Sounds like your fuel injectors are "leaking down" and in need of re-conditioning. You can get them rebuilt, flowmatched & balanced for about 100 bucks which includes the gasket set you need and the cold start valve rebuilt as well (if you have one).

http://www.cruzinperformance.com/

 

Grey,

You might have multiple problems.

The rich condition could be air filters or ignition as Ede described, leaking injectors as Mike advised, or a failing pressure regulator, throttle position sensor, or failing oxygen sensor. An oxygen sensor generally reports a more lean mixture as it begins to fail, and the ECM tends to compensate by enriching the mixture. The sensor signal has to get ridiculously low before an error code is set, and you might be just above that point.

The other problem may be with a worn throttle shaft that allows the throttle plates to bind in the bores. This would explain the need to "kick down" the throttle when cruising, and possible the high idle speed as well.

Do the general inspection as Ede suggested, and also check the throttle body for smooth operation. Clean the TB bores and IAC ports with a spray-type carburetor cleaner. Check the throttle operation by hand with the engine off to make sure it operates smoothly and returns to the idle position without binding. Look for polished areas around the throttle plates and bores where there might be interference. Open the throttle wide and try to move the throttle shaft up and down to check for excessive play.

When finished, scan for error codes. Even though the light may not be on, there may be stored error codes.

------------------
Later,
Vader
------------------
"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

My old firebird would flood quite often when I tried to start it. It was caused by a faulty coolent temp sensor. It would default to something like -40 degrees, which would cause the ECM to rich the hell out of it at startup. I don't recall if it continued after the car was running. I believe that *if* the car would start, it would then run fine. In any event, it's at least something to consider.

------------------
The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
"I didn't know a bored out Ford could go so slow" -Shenandoah