My car has been great for the last 4 years and now this. Problem: Hesitation coming off idle, hunts or misses at idle. Does this hot or cold. Runs great going down the road. NO check engine light. I am not the kind of person to start throwing parts at it til its fixed. I want to know why and what. If anyone could send me in the right direction I would appreciate it. Fuel pump and filter are about 5 months old. Module and coil 1 month old. Never have changed TPS or IAC. thanks dustin
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10:54 PM
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ka4nkf Member
Posts: 3702 From: New Port Richey, FL USA Registered: May 99
I assume that you have at least tuned it up, like new dist cap and rotor, new plugs and wiring if necessary, new fuel filter, new air cleaner filter, pcv valve. If not then I would this first. Don
The only way to tell if the sensors are performing properly is to do an ECM scan. Trouble codes only indicate catastrophic failure while a scan will tell you exactly what is going on. . Hesitation could also be caused by a weak spark or poor fuel supply.
Carbon, yes I did read the other thread but my problem seems to be a little different. Pump and filter are new(5mos) Corvette pump Air filter is new K&N Coil and Module are new Cap and rotor are new Plugs are two years old (Bosch +4) I just used carb cleaner on the throttle body and it seemed to help some but it did not fix it. I have a full tank of fuel and I put some lucas inj. cleaner in. I may order a TPS, I unplugged it while it was running and no change.....
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07:28 AM
ka4nkf Member
Posts: 3702 From: New Port Richey, FL USA Registered: May 99
Maybe you could measure the inputs and output of the TPS......If my rememberer is working there is a ground, 5 volts in and variable voltage out... I believe that with the throttle closed you get around 0 - .5 volts and wide open around 5 volts......and the voltage change should be smooth in between the two extremes...it may be 5 volts at closed throttle and 0 - .5 at open I cant remember which and my manual is at home........
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08:57 PM
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Huck Member
Posts: 146 From: Chesley, Ontario Registered: Feb 2001
I would start by replacing the plugs as well. I too went out and paid a lot of money for Bosch +4 plugs for my 87 GT, which replaced my regular bosch platinum I had previously. The +4's actually lasted only about 3 months for me, and I refused to think it was the plugs becuase I had just changed them less than 5000km ago. The +4's I noticed a great performance increase right after putting them in, they were good that way, but when I took them out to try a set of NGK's I immediately solved my hesitation upon acceleration problem. I just wish I took the forum members advice before I did my ignition control module and pickup coil!
Sorry... just reread my post and it came off a little harsh... but I don't see how your problem is much different... :shrugs:
If you do change out your plugs make sure to note if one cylinder is dirtier than the others... I am pretty sure that my hesitation is being caused by leaky injectors. Good luck!
