lowbird

Just wanted to see if someone could help with a problem I can't seem to fix.
I have an 88 350 that was a 305 tbi and I swaped to TPI. I have been working out most of the bugs but one I can't seem to get. When I drive the car it has a rough idle and also when I come to a stop and put it in park it idles around 1800 and wont go down till it cools down . The car runs ok but does have a slight miss at low rpm's . I have replaced cap,rotor,wires,plugs,maf,tps,iac,coil with new injectors (24lb) and almost all the sensors and checked for vacuum leaks also set the tps and iac and set the fuel press at 50 with the vacuum line unpluged .The car is mosly stock just headers, exhaust, gears and 52mm tb and a prom to match the currunt mods. I am going to make more mods but I would like to start with a good running car first. Any help would be appreciated . thanks

DJP87Z28

Try resetting the idle with the adjustment screw on the trottle body.

lowbird

Think that would work? I will try it. The idle is good in gear (700) .

lowbird

I tried that . it did not work, the screw does not even touch the bracket.

weaselbeak

How's your timing?

lowbird

Timing is at 6 with the wire unplugged.

Azrael91966669

are you useing an external tach to make sure its really idleing that high or useing the factory tach

if it was really idleing that high when you pop it in gear it would really be putting a load on the trans

my dads irocs tach is off and shows 1500 when 1st started then shows 800 in gear but really its 900 and 600 cold start and drops to 700 and 550 when warm but i checked with a external tach to see before i when searching for vac leaks and what not

jeff_blake

iTrader: (1)

could be a a faulty tach, one i have is a factory one, its 1k higher at all times. start, scanner reads 800, tach is 1800, ive learned to live with it.

lowbird

I checked that already . the engine races high you can tell it's not tach . I am starting to wonder if I was sold a bad iac motor .

jeff_blake

iTrader: (1)

u should be able to adjust the iac, least set it to factory and it may help you narrow it down.

lowbird

Ok back at this high idle still. replaced iac and still there. Not sure where to go now I have done tps,iac,maf, collant temp sensor,set timming,02, set fuel press and tune up. I have no vaccum leaks . I have reset that iac motor 10 times and it is ok for about ten mins each time than back to a 1500 rpm idle.

titus78

did you ever figure it out?

micktroup2

Mine is doing the same thing! Hope he comes back with a solution!

86IROCZ28NDC

Has anyone come up with the solution to this problem. I have an 86 camaro tpi with the same issue! I've done so much research and it seems like no one has an answer. It's making me irritated as f***.