88 305TPI Bogs out at 1/2-Full THrottle
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Joined: Sep 2011
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From: Illinois
Car: 88 Iroc-Z Convertible
Engine: 305 TPI
Transmission: 700R4
88 305TPI Bogs out at 1/2-Full THrottle
My car idles pretty rough at cold start... Previous owner said the 9th injector was bad so I'm gonna program that out once I get most of my other mods done.
Thats just background though. Real issue I've been experiencing is the car Bogs out and stumbles whenever I hit the gas from idle.
It seems to bog out around 1250RPM, and if I feather it past about 1750, it revs hard all the way up to 5k
If I give it just a little gas, I get no hesitation at all and can rev the motor normally to redline.
Just stumbles whenever I crack the throttle quickly. and only from idle. Once its over about 2k RPM, I can hammer it and the car pulls hard and drives great.
Today I changed the Spark plugs, Wires, Cap and Rotor. All the plugs were pretty clean. No obvious signs of any trouble at all.
Any Direction tracking this down would be appreciated.
TIA
Thats just background though. Real issue I've been experiencing is the car Bogs out and stumbles whenever I hit the gas from idle.
It seems to bog out around 1250RPM, and if I feather it past about 1750, it revs hard all the way up to 5k
If I give it just a little gas, I get no hesitation at all and can rev the motor normally to redline.
Just stumbles whenever I crack the throttle quickly. and only from idle. Once its over about 2k RPM, I can hammer it and the car pulls hard and drives great.
Today I changed the Spark plugs, Wires, Cap and Rotor. All the plugs were pretty clean. No obvious signs of any trouble at all.
Any Direction tracking this down would be appreciated.
TIA
Last edited by Impaqt; Oct 16, 2011 at 08:59 PM.
Thread Starter
Member
iTrader: (1)
Joined: Sep 2011
Posts: 330
Likes: 1
From: Illinois
Car: 88 Iroc-Z Convertible
Engine: 305 TPI
Transmission: 700R4
Re: 88 305TPI Bogs out at 1/2-Full THrottle
I just thought of something that might be related....
THe car never seems to get much hotter than 160 ( Assuming the dash between 100 and 220 is about 160)
I dont think a "performance" thermostat would of been installed in this car so I'm assuming its stuck open. (everything on the car was bone stock when I got it.)
Whats is "Normal" operating temp for these cars? Maybe the car isnt even going into closed loop right now? Gas mileage has been poor, but I havent really put enough miles on it to calculate what I'm getting. If its not going closed loop, would a faulty cold start injector cause an issue like I describe?
THe car never seems to get much hotter than 160 ( Assuming the dash between 100 and 220 is about 160)
I dont think a "performance" thermostat would of been installed in this car so I'm assuming its stuck open. (everything on the car was bone stock when I got it.)
Whats is "Normal" operating temp for these cars? Maybe the car isnt even going into closed loop right now? Gas mileage has been poor, but I havent really put enough miles on it to calculate what I'm getting. If its not going closed loop, would a faulty cold start injector cause an issue like I describe?
Thread Starter
Member
iTrader: (1)
Joined: Sep 2011
Posts: 330
Likes: 1
From: Illinois
Car: 88 Iroc-Z Convertible
Engine: 305 TPI
Transmission: 700R4
Re: 88 305TPI Bogs out at 1/2-Full THrottle
Disconnected my MAF sensor last night. Popped the SES light on immediately and the car would Idle OK, but wouldn't rev past 2500 or so.
AFter reconnecting the MAF, it actually seems to clear up a little bit, but the stumble is still there when I quickly open the throttle. If I hold it open to try to work through the bogging, I get a pretty loud backfire through the intake. Scared me... lol....
Maybe Timing is off?
Going to swap the Fuel Filter this weekend and pick up a Timing light from my brother. I should also check the TPS and IAC while I'm in there from what I've read so far.
Its funny.. I've found no fewer than a dozen threads similar to mine, and very few of them come to any sort of resolution.
AFter reconnecting the MAF, it actually seems to clear up a little bit, but the stumble is still there when I quickly open the throttle. If I hold it open to try to work through the bogging, I get a pretty loud backfire through the intake. Scared me... lol....
Maybe Timing is off?
Going to swap the Fuel Filter this weekend and pick up a Timing light from my brother. I should also check the TPS and IAC while I'm in there from what I've read so far.
Its funny.. I've found no fewer than a dozen threads similar to mine, and very few of them come to any sort of resolution.
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