Doing a little trouble shooting with this 1991 Caprice I just acquired. It's a 305 TBI car and otherwise run of the mill.
Problem it has, is that anything beyond 25% throttle it falls flat on its face. It's particularly bad before it's had time to warm up. Once it warms up the condition is still present but you can at least hammer the throttle and it'll get with it slightly better.
So, basically what were looking at is, any pedal input between 25% and 100% throttle causes the car to cut out badly. Car surges at idle at random once it's warmed up, otherwise smooth. Car hardly idles when the motor is cold. Car revs fine in park or neutral, no load on it.
I checked for broken vacuum lines, vacuum leaks at the TB base. Nothing there.
Pulled codes from it and they were:
33 Map - high voltage signal
34 Map- low voltage signal
44 O2- lean
22 TPS - low signal voltage
23 Manifold air temp
SO, I replaced the Map sensor and TPS with brand new ones, cleared the codes and SHAZZAM! Still runs like turd. :dunno:
Nothing has changed, and now it doesn't have any codes stored that I've been able to retrieve. Drove it around for 5 minutes and let sit in the driveway for 15 mins at idle and still no codes set.
I thought for certain the sensors would have at the very least improved the condition even somewhat.
Anyone seen this before on one of these cars?
I'm wondering if it's a weak fuel pump. The injectors appear to be spraying as they should at idle, of course that doesn't mean they are while it's under a load in gear and I'm not quite talented enough to watch them while driving it.
Looking forward to everyone's input on this. More looking forward to being able to drive the car with it running correctly, it's a good riding cruiser. It does however need to be cleaned inside very badly as the inside smells like fat sweaty old guy and the interior has an inch of dust and funk through out.
:WTF:
Thanks in advance guys!
Problem it has, is that anything beyond 25% throttle it falls flat on its face. It's particularly bad before it's had time to warm up. Once it warms up the condition is still present but you can at least hammer the throttle and it'll get with it slightly better.
So, basically what were looking at is, any pedal input between 25% and 100% throttle causes the car to cut out badly. Car surges at idle at random once it's warmed up, otherwise smooth. Car hardly idles when the motor is cold. Car revs fine in park or neutral, no load on it.
I checked for broken vacuum lines, vacuum leaks at the TB base. Nothing there.
Pulled codes from it and they were:
33 Map - high voltage signal
34 Map- low voltage signal
44 O2- lean
22 TPS - low signal voltage
23 Manifold air temp
SO, I replaced the Map sensor and TPS with brand new ones, cleared the codes and SHAZZAM! Still runs like turd. :dunno:
Nothing has changed, and now it doesn't have any codes stored that I've been able to retrieve. Drove it around for 5 minutes and let sit in the driveway for 15 mins at idle and still no codes set.
I thought for certain the sensors would have at the very least improved the condition even somewhat.
Anyone seen this before on one of these cars?
I'm wondering if it's a weak fuel pump. The injectors appear to be spraying as they should at idle, of course that doesn't mean they are while it's under a load in gear and I'm not quite talented enough to watch them while driving it.
Looking forward to everyone's input on this. More looking forward to being able to drive the car with it running correctly, it's a good riding cruiser. It does however need to be cleaned inside very badly as the inside smells like fat sweaty old guy and the interior has an inch of dust and funk through out.
:WTF:
Thanks in advance guys!
