Ok so I just awoke the beast from a 7 year nap (was prepped and started 6 months ago for the first time in 7 years, but then another 6 month nap). 1990 IROC 305. Trouble is, she now idles around 2000-2500rpm and I don't get power till around 3500-4500rpm. Shift light doesnt come on all the time nowbut when it does come on it seems to tell me to shift around 3500-4500rpm.Always seems to be up around orange and redline to move. In 3rd gear going 30-40kmh I'm around 4000rpm. On the highway just to go 120kmh I'm in the orange in 5th!

I don't remember things being this high back in the day. Seems like everything happens 1000-1500rpm too high. Nothing has really been touched expcept oil and plug clean, air filters, rad flush and brakes. Does it just need to have the snot run out ofher more? I've had it idle as low as 1500rpm, but only when its really hot. I understand at cold start it idles high, but it should prgressivly go down with warm up. What is the normal idle, isnt it around 800-1200?

Also seems pretty gutless.

Still have to change fuel filter.

Any ideas??

 

sounds like a vacuum leak to me, try spraying carburetor spray around the plenum and runners, and also around the intake manifold. If there is a leak there it will drop the rpm's when you spray it. If that does not tell you anything then you might check the idle air control valve and possibly check out the distributor components or replace it alltogether. Have you put a timing light on it yet?

 

This is a long shot, but it could be the clutch plates slipping? Then again that wouldn't happen when its idling. Yah, I'd have to agree with roller. Good luck.

 

Clutch Plate isn't that far off. It was a brand newCenter Force dual friction put in 6 months prior to hiburnation...aparently its all ****ed...nofluid in the secondary cylinder. Would that cause it to slip??

Also aparently I've blown a head gasket too

 

are you getting a check engine light? sounds just like the prob i had with my 91 rs 305 and it was the throttle positioning sensor, if you end up replacing it, get the aftermarket one, that is adjustable, good luck Dhighway.

 

but should,ve ask if it,s tbi? im thinking no if it,s the IROC it,s tpi, then it,s probably the idle control sensor, of course that would also throw a code, good luck.

 

Yeah it's TPI 305, no engine light though. The shift light didn't come at first but after a while it would come on, but again, was coming on 1000-1500rpm higher than I remember, sometimes not coming on at all.

Just wondering what perameters it uses to decide shift. I know throttle senser is probably one, but what else?

 

do you have the 700r4 trans (auto) even if it is manuel trans, id take the 194 bulb on the back of the instrument cluster, and pitch it! ive never held much stock in those shift lights personally, i much prefer the human ear and driver feel, for when to shift, ie: (manuel) of course.I have been driving big rigs before my first paper route,and short of taking off, dont clutch a gear, engine matched with trans speed and they drop right in.Now your trans being the 700r4 auto?is going to shift, depending on throttle pressure, when it needs to. does it lurch in gear, with your foot on your brake, or want to run off, even with a heavy brake applied? cross check your tach with that of another, have it scoped! also check trans kickdown cable, unless it,s a manuel trans? keep me posted, i,ll also check with my bro, ase tech, diesel mech, he,s got 30+ plus years wrenching, and is damn good, he actually told me the valves were out of adjustment on my car! he could hear it running in the background while i was talking to him on the phone, so i made him adjust them. LOL anyway good luck, wel narrow it down later,