this is getting very annoying, i have spoken of this similar problem in a previous thread a while back.
what happens is as follows
start from cold, runs for about 30 seconds then the idle slowly drops where you have to put your foot in the gas, sputters a little, surges to normal for a few seconds, then sputters and drops again, this repeats for a while until a little past half way to operating temp if you are sitting still. if you start driving before it starts happening, it will only sputter and lose power once then be okay. it will do fine once at temperature.
if you let it sit and heat soak and go to start, it will barely run and sputter when you give it some gas all the way until almost operating temp. then runs fine at temp. it feels like it's leaning it out
i have replaced nearly everything in the fuel system aside from the actual fuel distributor (replaced line pressure o rings), the AAR, the impulse relay, and the thermo time sensor for the cold start valve. all vaccum lines and intake seals are new. timing is set to 18 btdc with CO adjusted accordingly. i havr tried returning the timing and CO to stock but results are the same.
today i replaced the lambda temp sensor under the intake and crimped on a new connector (this is pre constant idle computer era), thinking that would fix the problem, nope, still there, but with an additional problem on the highway. you will cruise at 75 t0 80 for a while, everything fine, let off the gas and it dip below 2400 rpm and suddenly will defuel the engine, getting back on the gas will have very little power with sluggish response and many misfires. this wont return to normal until you have come to a stop and either let the car die amd restart or you lay on the gas lightly at a stop light in neutral for a minute or two. it was 95?F today with a heat index of 103. funny thing is it will overcool on those days only going to 3/4 operating temp on highway.
it used to be you could unplug the o2 sensor and iy would default and not have the issue, now it's keeping it alive as i unplug it, it sputters and comes close to dying. i can hear the frequency valve buzzing more when this happens leading me to believe it's going lean.
this now has me thinking of three possible problems.
1. the coolant has purple ice water wetter in it which has done well to keep the car cool, but im suspecting it's causing too much heat transfer to the sensor ans thermostat , causing it to think it's warmer than it is and opening the (2.5 year old) thermostat to open early. as theses problems were not really prevalent during winter.
2. disturbing the lambda temp cable caused an intermittency which would make it have no signal. (unplugged the sensor for a hot start with no real change) may be time for a new harness.
3. the kjet ecu has shat the bed.
suggestions, thoughts?
what happens is as follows
start from cold, runs for about 30 seconds then the idle slowly drops where you have to put your foot in the gas, sputters a little, surges to normal for a few seconds, then sputters and drops again, this repeats for a while until a little past half way to operating temp if you are sitting still. if you start driving before it starts happening, it will only sputter and lose power once then be okay. it will do fine once at temperature.
if you let it sit and heat soak and go to start, it will barely run and sputter when you give it some gas all the way until almost operating temp. then runs fine at temp. it feels like it's leaning it out
i have replaced nearly everything in the fuel system aside from the actual fuel distributor (replaced line pressure o rings), the AAR, the impulse relay, and the thermo time sensor for the cold start valve. all vaccum lines and intake seals are new. timing is set to 18 btdc with CO adjusted accordingly. i havr tried returning the timing and CO to stock but results are the same.
today i replaced the lambda temp sensor under the intake and crimped on a new connector (this is pre constant idle computer era), thinking that would fix the problem, nope, still there, but with an additional problem on the highway. you will cruise at 75 t0 80 for a while, everything fine, let off the gas and it dip below 2400 rpm and suddenly will defuel the engine, getting back on the gas will have very little power with sluggish response and many misfires. this wont return to normal until you have come to a stop and either let the car die amd restart or you lay on the gas lightly at a stop light in neutral for a minute or two. it was 95?F today with a heat index of 103. funny thing is it will overcool on those days only going to 3/4 operating temp on highway.
it used to be you could unplug the o2 sensor and iy would default and not have the issue, now it's keeping it alive as i unplug it, it sputters and comes close to dying. i can hear the frequency valve buzzing more when this happens leading me to believe it's going lean.
this now has me thinking of three possible problems.
1. the coolant has purple ice water wetter in it which has done well to keep the car cool, but im suspecting it's causing too much heat transfer to the sensor ans thermostat , causing it to think it's warmer than it is and opening the (2.5 year old) thermostat to open early. as theses problems were not really prevalent during winter.
2. disturbing the lambda temp cable caused an intermittency which would make it have no signal. (unplugged the sensor for a hot start with no real change) may be time for a new harness.
3. the kjet ecu has shat the bed.
suggestions, thoughts?
