Tough starting and running rich
05-20-2015, 12:32 AM
#61
Rennlist Member
Man, I wish I read this thread sooner, it's a bad MAP sensor... I had one go bad with my M-tune, same cutting at 5200. Ask Josh to send you a new one, and/or test the one you have now. I was getting weird readings. The M-tune is turning on the boost protection because it can't read the pressure properly.
*disclaimer* this is my hunch, Josh will know best.
*disclaimer* this is my hunch, Josh will know best.
05-20-2015, 12:38 AM
#62
Rennlist Member
Man, I wish I read this thread sooner, it's a bad MAP sensor... I had one go bad with my M-tune, same cutting at 5200. Ask Josh to send you a new one, and/or test the one you have now. I was getting weird readings. The M-tune is turning on the boost protection because it can't read the pressure properly.
*disclaimer* this is my hunch, Josh will know best.
*disclaimer* this is my hunch, Josh will know best.
05-20-2015, 12:51 AM
#64
Rennlist Member
Thread Starter
05-20-2015, 01:26 PM
#65
Rennlist Member
I dont recall it backfiring (though it does "pop" now under WOT on E85 between shifts... pretty normal on the track as the exhaust is so hot), I only drove the car a handful of times before I diagnosed and resolved the issue. I also don't have an AFR, but if the MAP sensor is throwing erroneous info, it very well could be causing things to run rich. I seem to recall Josh mentioned in the absence of the MAP sensor, the tune would run "a conservative map" to ensure the tune didn't fry the engine with a lean map.
I looked at Josh's guide on the voltage readings and my readings were erratic. It would hit the 1.6 volts Josh said to look for, then bounce to 0, then to 1.6, then to 0 (and numbers I'm between). I swapped out the MAP sensor and it held at 1.6. Josh did mention that when he hooked up the MAP sensor I sent back, it bench tested okay... so who knows why it struggled in my car. The new one he sent didn't have the voltage swings like the first one did, and the car has been great ever since.
I looked at Josh's guide on the voltage readings and my readings were erratic. It would hit the 1.6 volts Josh said to look for, then bounce to 0, then to 1.6, then to 0 (and numbers I'm between). I swapped out the MAP sensor and it held at 1.6. Josh did mention that when he hooked up the MAP sensor I sent back, it bench tested okay... so who knows why it struggled in my car. The new one he sent didn't have the voltage swings like the first one did, and the car has been great ever since.
05-20-2015, 01:42 PM
#66
I dont recall it backfiring (though it does "pop" now under WOT on E85 between shifts... pretty normal on the track as the exhaust is so hot), I only drove the car a handful of times before I diagnosed and resolved the issue. I also don't have an AFR, but if the MAP sensor is throwing erroneous info, it very well could be causing things to run rich. I seem to recall Josh mentioned in the absence of the MAP sensor, the tune would run "a conservative map" to ensure the tune didn't fry the engine with a lean map.
I looked at Josh's guide on the voltage readings and my readings were erratic. It would hit the 1.6 volts Josh said to look for, then bounce to 0, then to 1.6, then to 0 (and numbers I'm between). I swapped out the MAP sensor and it held at 1.6. Josh did mention that when he hooked up the MAP sensor I sent back, it bench tested okay... so who knows why it struggled in my car. The new one he sent didn't have the voltage swings like the first one did, and the car has been great ever since.
I looked at Josh's guide on the voltage readings and my readings were erratic. It would hit the 1.6 volts Josh said to look for, then bounce to 0, then to 1.6, then to 0 (and numbers I'm between). I swapped out the MAP sensor and it held at 1.6. Josh did mention that when he hooked up the MAP sensor I sent back, it bench tested okay... so who knows why it struggled in my car. The new one he sent didn't have the voltage swings like the first one did, and the car has been great ever since.
05-20-2015, 03:23 PM
#67
Rennlist Member
It's a tough line to walk, without a strong source to offer "test" parts, you are often left in a lurch. Hopefully not all the parts were in vein.
one other quick note - You may want to confirm the ground is solid on the MAP sensor, that may also be causing problems (if the MAP sensor is still good)
one other quick note - You may want to confirm the ground is solid on the MAP sensor, that may also be causing problems (if the MAP sensor is still good)
Last edited by Xaerran; 05-20-2015 at 05:12 PM.
05-20-2015, 09:40 PM
#68
Rennlist Member
Thread Starter
It's a tough line to walk, without a strong source to offer "test" parts, you are often left in a lurch. Hopefully not all the parts were in vein.
one other quick note - You may want to confirm the ground is solid on the MAP sensor, that may also be causing problems (if the MAP sensor is still good)
one other quick note - You may want to confirm the ground is solid on the MAP sensor, that may also be causing problems (if the MAP sensor is still good)
Map sensor is reading a steady -1.6
05-20-2015, 10:39 PM
#69
Rennlist Member
05-20-2015, 10:51 PM
#70
Rennlist Member
Thread Starter
hI was really hoping the MAP was my problem.
I am waiting on the Tuner to be done so I can get the Logger/Tuner.
Also, the grounds on both the MAP and MAF are good.
05-20-2015, 11:37 PM
#71
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05-21-2015, 12:15 AM
#72
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Thread Starter
05-22-2015, 10:32 PM
#73
Rennlist Member
Thread Starter
I drove 60 miles to our cottage today.
My AFR's are all over the place.
Cruise in 5th gear 2.5k showing anywhere between 12.5 and 14.0
Under WOT it will go rich (mid 10's) then above 4k or so it leans back to high 11's.
Joshua has been helping me and I purchased the logger so I am going to get more data before replacing any more parts.
BTW...my no start condition returned so I changed the DME relay while it was acting up and it immediately started and has started every time since. I guess sometimes they die a slow death.
My AFR's are all over the place.
Cruise in 5th gear 2.5k showing anywhere between 12.5 and 14.0
Under WOT it will go rich (mid 10's) then above 4k or so it leans back to high 11's.
Joshua has been helping me and I purchased the logger so I am going to get more data before replacing any more parts.
BTW...my no start condition returned so I changed the DME relay while it was acting up and it immediately started and has started every time since. I guess sometimes they die a slow death.
05-29-2015, 07:39 PM
#74
Rennlist Member
Thread Starter
Waiting on logger and it got worse today!
Left office to head home and it started stumbling and bucking under light to medium throttle around 2800 RPM's.
If I accelerate lightly, it will go to redline but anymore than real light acceleration, it stumbles at 2.8k and have to back off throttle.
AFR was even more rich than before.
3rd gear at 2.8k RPM it is high 11's.
Accelerating lightly I am seeing mid 10's.
Idle AFR 14.2-14.7
Left office to head home and it started stumbling and bucking under light to medium throttle around 2800 RPM's.
If I accelerate lightly, it will go to redline but anymore than real light acceleration, it stumbles at 2.8k and have to back off throttle.
AFR was even more rich than before.
3rd gear at 2.8k RPM it is high 11's.
Accelerating lightly I am seeing mid 10's.
Idle AFR 14.2-14.7
05-29-2015, 11:43 PM
#75
Perplexing.
The Logger should hopefully help give us a view into what's going on.
This also sorta-kinda sounds like the issue I was having last summer. Not exactly, but similar.
Does it do it 100% of the time? Or does it come and go? Does it seem worse when you've got a heavy electrical load on the car (like headlights on)?
Part of me wonders if you're getting the same goofy interference issue I had with my car last year. And part of me wonders if it's something like MAF power cutting out.
The Logger should hopefully help give us a view into what's going on.
This also sorta-kinda sounds like the issue I was having last summer. Not exactly, but similar.
Does it do it 100% of the time? Or does it come and go? Does it seem worse when you've got a heavy electrical load on the car (like headlights on)?
Part of me wonders if you're getting the same goofy interference issue I had with my car last year. And part of me wonders if it's something like MAF power cutting out.