92 RS 305 TBI Idle problems
92 RS 305 TBI Idle problems
Ive looked at all the posted I could find and done all the things said to fix the problem but no luck.
The problem is after about 5 or 10 minutes the car will not idle by itself. Other than idling you wouldnt think anything was wrong with the car. No power loss, 100% responsive, shifts perfect, etc. But when you stop it will either cut off instantly or idle eradticly and then cut off. To keep it running you need to put your foot on the brake and gas. Makes leaving someones house with gravel near impossible as when you start it after is fulling warmed up it will not idle in park, so you have to two foot it and then try to put it in gear and keep it on, cut off 7 times trying to leave, and left tons of gravel holes since power breaked it.
So I searched the internet and did the following.
I changed the spark plugs and wires.
Changed the TPS sensor
Changed the IAC Sensor
Changed the EGR valve
Checked for vacuum leaks (found none)
Now they also say replace the fuel pump, which I will if I must but I'm not convinced it could be the problem, which leads me to this question about the fuel pump.
Its a few years old, replaced it when I got the car. I put a fuel psi tester on it and it remains at 10 psi. Now some people say 9-13 is good, some say 11-15 is good. Wouldn't my performance be bad if my pump was bad, I mean other than idle its has all the power it did normally?
One other piece of info that may be useful, it looks to me by the tach that its a miss. The tac will be at 1000, drop instant to 800 then instant back to 1000, and kind of shutter to 100, then up and finally cut off. Hard to explain but almost looks like something electrical is cutting on and off causing this.
So any thoughts?
The problem is after about 5 or 10 minutes the car will not idle by itself. Other than idling you wouldnt think anything was wrong with the car. No power loss, 100% responsive, shifts perfect, etc. But when you stop it will either cut off instantly or idle eradticly and then cut off. To keep it running you need to put your foot on the brake and gas. Makes leaving someones house with gravel near impossible as when you start it after is fulling warmed up it will not idle in park, so you have to two foot it and then try to put it in gear and keep it on, cut off 7 times trying to leave, and left tons of gravel holes since power breaked it.
So I searched the internet and did the following.
I changed the spark plugs and wires.
Changed the TPS sensor
Changed the IAC Sensor
Changed the EGR valve
Checked for vacuum leaks (found none)
Now they also say replace the fuel pump, which I will if I must but I'm not convinced it could be the problem, which leads me to this question about the fuel pump.
Its a few years old, replaced it when I got the car. I put a fuel psi tester on it and it remains at 10 psi. Now some people say 9-13 is good, some say 11-15 is good. Wouldn't my performance be bad if my pump was bad, I mean other than idle its has all the power it did normally?
One other piece of info that may be useful, it looks to me by the tach that its a miss. The tac will be at 1000, drop instant to 800 then instant back to 1000, and kind of shutter to 100, then up and finally cut off. Hard to explain but almost looks like something electrical is cutting on and off causing this.
So any thoughts?
Re: 92 RS 305 TBI Idle problems
Not sure what the problem is seeing that you replaced those specific sensors. But I can tell you that from what you're describing then it is most likely not the fuel pump, a bad fuel pump would have symptoms like hesitation during acceleration, hard to start up from a cold start, and symptoms that you have when you're running out of gas such as car about to die with foot on the gas and letting off it keeps it from stalling. So you may be good on that fix.
Last edited by Dkelz313; May 26, 2013 at 09:24 PM.
Re: 92 RS 305 TBI Idle problems
Update.
I did some more checking, and decided to look at the cts. If I unplug it the car will cut up so I know it affects the car alot. So I checked the volts and looks like its only getting 2.5 coming in. I thought it was supposed to be getting 5 volts, but as usual some people say 2-7 while others say 5. So I went on and replaced the cts (coolant temp sensor) and nothing changes. At this rate I will have replaced all the sensors before im done.
I did some more checking, and decided to look at the cts. If I unplug it the car will cut up so I know it affects the car alot. So I checked the volts and looks like its only getting 2.5 coming in. I thought it was supposed to be getting 5 volts, but as usual some people say 2-7 while others say 5. So I went on and replaced the cts (coolant temp sensor) and nothing changes. At this rate I will have replaced all the sensors before im done.
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