acedraven

Im looking for any information as to what could cause these problems, maybe something related that could cause them? Ill try to explain things as best i could. First off the car is a 1994 LT1, its got about 175k on it atm. I bought the car about 8-9 months ago the owner had new wires, new opti unit and i believe a new ecm put in a few months before the purchase. I changed the oil, flushed the radiator, checked/toped off fluids put new plugs in and lubed the joints (basic maintaince stuff). The car has been a daily driver since and i have had no problems with it. A few weeks ago, the car started becoming hard to start at times, (sometimes i could just jump in and itd start right up no problem, and sometimes it would take a few cranks). Beyond that the car drove perfect. At idle the rpms would also jump to about 1500 or so and then it would adjust itself at the 800 or so mark, Ive read that this is pretty normal because the idle speed is adjusted by the ecm. Well the past week or so sometimes the rpm's will just not drop. Ive even had the car start and idle at 2k and not drop down. on top of this two days ago while driving the car seemed to lose power, rpms would shoot up to about 4k or so and it would just be kinda coasting along and not be pulling as it should. I pulled a few plugs and they seemed fine, wires are ok, and are nice and tight. I have the following codes, 4. H29 H22, 9 H64. The air pump has not been working since purchase because of a burnt relay. Also about a week or so ago the Service ASR light came on. Please just give me some ideas on what to look at , Ive been checking numerous things such as the iac vavle..etc but I dont want to say that i have defiantly ruled anything out. Thanks for your time and the info. - phillip

CFI-EFI

Start by following the trouble shooting charts in your FSM to track down and cure the causes of those trouble codes.

There is no idle speed adjustment for your car. The idle speed is burned into and controlled by the computer through the IAC, based on various conditions. Any attempt to change the idle speed without reprogramming, is going to mess up your minimum air adjustment setting.

Your high idle speeds are caused by a vacuum leak.

RACE ON!!!

mk842766

What he said...

Cheers,
Michael

89 Bob L

MarkBychowski

vacuum leak

The ASR error could be related -- there's a vacuum line on the passenger side that goes over to the cruise module. If that line fell off, broke, whatever, it could cause both problems.

Aside from that, just go around the intake pulling vacuum lines and pluging them at the manifold to see if you can find the culprit.