Holden202 wrote:i'd be checking a few things .....
1. tps voltage when logged in the monitor is 0v most of the time, this is an issue, it should be about .5v at 0 % tps and should increase from there.
2. apparently you've changed gears and are doing 4000rpm in atleast 2nd gear (hard to say what gear its in) and the road speed is 18kph! so either something is wrong there or your pulses per km is up to shit!
3. for such little throttle opening im very suprised the map sensor is sitting on nearly 100kpa most of the time!
my guess is you have a dodgy earth or reference voltage issue ...
one way to test it would be to put a wire on the tpe reference voltage line and then put that into the 0-5v input and see what the reference voltage is doing when you get the issue.
definately sounds like something is dodgy like the reference voltage though cause that feeds 4v to alot of the sensors so if its wrong so will be the readings from them!
O.k. then. The TPS voltage test was done by the cars owner and he's a trades electrician so there is room for error I suppose. I'll have to get on the car with him and go through these things you've outlined here. You're right though, bit suss that both the TPS voltage low and VSS signal isn't altering on the TP dash monitor screen!
We had this issue where a CEL TPS low voltage and stumbled acceleration would occur before.
After I fitted larger 36lb/hr injectors and adjusted the base injector rate which made some progress. After a couple of hours of street logging in which I was trying to use the VE calc excel table from the forum and realized I wasn't making progress, the stumbled acceleration issue and CEL tps voltage low returned. By this stage it was 2a.m. and brain fade was setting in so we called it a night lol.
I am starting to feel like a goose when I make time for my mate n I to get together to tune his car and little issues like this are evidently outside my present abilities.
thats good, alot easier to solve than intermittant....
i'd try another ecm if you have one, that would be a quick easy check, failing that start looking at the wiring going to the tps and make sure everything is within specs ..... you don't even need to take it for a drive, see if you can get tps to read 0-100% with the engine off and then see what the tps volts are when your doing that.
No matter what the question is, the answer is always more horsepower!
i'm not sure they are necessarily related, but TPS and map sensor issue i believe are.... they share a common reference voltage too which is the grey wire i believe.
use the monitor screen and map out the tps and map sensor voltages .... i'll see that there is a bit of a trend of them both going berko, map sensor reading 100kpa all the time would explain the pig rich issue your seeing when the issue occurs.
weather its a dodgy sensor or wiring or what i can't say, but the fact your seeing 35% or so TPS and the voltage is sitting on 0v is not right and without knowing what actual TPS your giving it its hard to say what the map should be reading but it seems to be on 100kpa for far longer than i would expect to see from what the other things are showing.
No matter what the question is, the answer is always more horsepower!
VSS is probably not faulty either, as holden202 mentioned check your PPK value (Road speed params - Speed sensor constant Pulses/Kilometer). VN needs it changed to 1250 from the standard VR BLCF value of 6250.
The ECU is calculating a default TPS %, so even with 0v from the sensor you see some TPS %. The voltage tells the true story.
Great tips there fellas. At last I'm armed with a bit more relevant knowledge to help while troubleshooting. Electrical fault diagnosis sure isn't my strong point.
