88 sunbird gt idle problems - Second Generation Forum

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88 sunbird gt idle problems
Tuesday, February 14, 2012 1:45 PM
My 88 sunbird gt with a 2.0l turbo motor is having problems at idle.The motor itself is completely rebuilt. I used a paperclip to get the trouble codes out of the car and it gave me these codes: 34,35, and 45. I looked up these codes an apparently they are map sensor circuit error (signal low indicating high vacuum), IAC problem or idle error, and o2 sensor ( rich condition indicated). The car when first started up will usually raise up and idle around 2000 rpm and sometimes slowly increases and can go al the way up 3000 rpm. Eventually it will drop down to around 1000 or so and starts missing really bad and sometimes stalls. Anybody ever run into similar problems or have any ideas of how to figure this out? Any help at all would be greatly appreciated.

Re: 88 sunbird gt idle problems
Tuesday, February 14, 2012 10:24 PM
Ron Love Online
To check for code 34 map sensor here is how.Using a mulitimeter volts selection on meter,Unlplug sensor plug,using a jumper wire place wires into terminal A and C( the two out side terminals) to thier corresponding terminals.In other words remove plug run a jumper from the plug to the map A to A then C to C .Connect teh positive lead of the multimeter to terminal B (center terminal) of the sensor and the negative lead (from mulitmeter) to a good ground.Key ON only (no engine running) voltage should be 4.5-5 volts.Start engine and let warm up or unless already run reading should be different from original,and should fluctuate with changes in vacumm.If it does NOT check vac hose,and if hose is OK your sensor is BAD! To check the MAF sensor mass air flow tap the flat portion of the sensor with a screwdriver handle lightly and engine needs to be running,IF the engine stumbles or dies the sensor is bad.The 45 code is being set bc your ecm is running in a LOOP and causing it to NOT read the oxygen sensor because it is running RICH.I suspect your MAP is probably bad,however your IAC idle air control could be too,but go cheap first and need to dig a touch for testing it .I am tired and just check the two items first because either can cause the cars idle to be high,and run rich kicking the IAC code,and oxygen sensor as well.Being your IAC is probably the orig you might want to change it out regardless.I would def check ur map,if this goes bad or voltage is wayyy of it screws up the car idle,running period.Sorry for the book but there is no short way to explaing it.Print this off u will never remember it.



Re: 88 sunbird gt idle problems
Thursday, March 22, 2012 4:21 PM
Well I think I finally found the cause of my problems.I had a relative of mine who is a mechanic look at the car and he told me the fuel pump is gone and that it is only putting out 5lbs of pressure.So gonna order a new fuel pump and hope that was all that was wrong.But thanks again for the help and suggestions.
Re: 88 sunbird gt idle problems
Thursday, March 22, 2012 9:02 PM
Ron Love Online
Ok cool I guess the symptoms can be loco and isolating them can be stupid time waste.A simple psi check can do wonders! I would go AC delco on your pump if you already have not bought it.Took me 3hrs to do the whole job,and MAKE sure you lube your tank straps with liquid wrench or bp blaster a day or two before and use new clamps on your hoses and or replace them.I meant the bolts and nuts but you know thinking faster than I typed it.



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