Concern: FD dies after high RPM driving.
#1
Concern: FD dies after high RPM driving.
Good Morning,
Here are the facts:
1. bought my car 8 months ago
2. Has a street ported engine with 3k or so on it
3. 550cc primary, 1200cc secondary injectors
4. Starts fine and idles fine after it is warmed up
5. It takes at least 5 mins after I start the car for the rpm to get down to 1k. The start up process seems to be much different than my previous rx7s. My previous rx7s started up and it was high rpm for about 10 to 15 seconds before it came down.
5. runs super rich. basically it backfires after after getting up to 5k rpm or so when I let off the gas
6. I have a Odyssey PC680 battery
Here is the concern:
If I drive the car and keep it under 4k rpm I can drive it without issues
As soon as I get over 5k rmp or so (not sure exactly) and kind of step on it where the boost kicks in, the car starts to act funny at a red light or at stop and go traffic. The idle begins to jump and then the car dies.
The only way I found to counter that is to rev the engine at idle to keep the rpm from dropping and the car turning off. It feels as if the car is chocking and then just turns off.
Can it be:
The battery is to strong enough to power the car?
It needs a tune?
The injectors need to be cleaned?
Sensor?
Any suggestions? Thanks
Here are the facts:
1. bought my car 8 months ago
2. Has a street ported engine with 3k or so on it
3. 550cc primary, 1200cc secondary injectors
4. Starts fine and idles fine after it is warmed up
5. It takes at least 5 mins after I start the car for the rpm to get down to 1k. The start up process seems to be much different than my previous rx7s. My previous rx7s started up and it was high rpm for about 10 to 15 seconds before it came down.
5. runs super rich. basically it backfires after after getting up to 5k rpm or so when I let off the gas
6. I have a Odyssey PC680 battery
Here is the concern:
If I drive the car and keep it under 4k rpm I can drive it without issues
As soon as I get over 5k rmp or so (not sure exactly) and kind of step on it where the boost kicks in, the car starts to act funny at a red light or at stop and go traffic. The idle begins to jump and then the car dies.
The only way I found to counter that is to rev the engine at idle to keep the rpm from dropping and the car turning off. It feels as if the car is chocking and then just turns off.
Can it be:
The battery is to strong enough to power the car?
It needs a tune?
The injectors need to be cleaned?
Sensor?
Any suggestions? Thanks
#2
All out Track Freak!
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Location: Charlottesville VA 22901
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Good Morning,
Here are the facts:
1. bought my car 8 months ago
2. Has a street ported engine with 3k or so on it
3. 550cc primary, 1200cc secondary injectors
4. Starts fine and idles fine after it is warmed up
5. It takes at least 5 mins after I start the car for the rpm to get down to 1k. The start up process seems to be much different than my previous rx7s. My previous rx7s started up and it was high rpm for about 10 to 15 seconds before it came down.
5. runs super rich. basically it backfires after after getting up to 5k rpm or so when I let off the gas
6. I have a Odyssey PC680 battery
Here is the concern:
If I drive the car and keep it under 4k rpm I can drive it without issues
As soon as I get over 5k rmp or so (not sure exactly) and kind of step on it where the boost kicks in, the car starts to act funny at a red light or at stop and go traffic. The idle begins to jump and then the car dies.
The only way I found to counter that is to rev the engine at idle to keep the rpm from dropping and the car turning off. It feels as if the car is chocking and then just turns off.
Can it be:
The battery is to strong enough to power the car?
It needs a tune?
The injectors need to be cleaned?
Sensor?
Any suggestions? Thanks
Here are the facts:
1. bought my car 8 months ago
2. Has a street ported engine with 3k or so on it
3. 550cc primary, 1200cc secondary injectors
4. Starts fine and idles fine after it is warmed up
5. It takes at least 5 mins after I start the car for the rpm to get down to 1k. The start up process seems to be much different than my previous rx7s. My previous rx7s started up and it was high rpm for about 10 to 15 seconds before it came down.
5. runs super rich. basically it backfires after after getting up to 5k rpm or so when I let off the gas
6. I have a Odyssey PC680 battery
Here is the concern:
If I drive the car and keep it under 4k rpm I can drive it without issues
As soon as I get over 5k rmp or so (not sure exactly) and kind of step on it where the boost kicks in, the car starts to act funny at a red light or at stop and go traffic. The idle begins to jump and then the car dies.
The only way I found to counter that is to rev the engine at idle to keep the rpm from dropping and the car turning off. It feels as if the car is chocking and then just turns off.
Can it be:
The battery is to strong enough to power the car?
It needs a tune?
The injectors need to be cleaned?
Sensor?
Any suggestions? Thanks
Hopefully I'm wrong.
#3
Engine was rebuilt by Ricks Rotary Performance about 6 years ago. The previous owner got back surgery and he couldn't drive it after that so the car sat in his garage for years. He started it from time to time. Rick also put the tune on it but it seems like it is a generic tune because it is running super rich.
When I bought one of the things that sealed the deal was the fact that it was rebuilt by a reputable shop and the PO provided all the receipts for the rebuilt.
The PO was not car savvy at all so I know he wouldn't know to turn up the idle to smooth out the idle but who knows, someone else might have done it for him...
Last edited by ArmAnirx7; 12-05-15 at 12:48 PM.
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#9
Although, I am having a hard time getting the damn rats nest out. I need to do a little more research on the forum to get some info on what the easiest way to take out the rats nest is.
#13
I pinched it with some pliers and it is grabbing very good now. I have to pull on it before it comes off where before I can literally lift it off.
#14
Senior Member
iTrader: (2)
I'm not sure just what that wire is as the "red" circle somewhat obscures where it connects, but that is not a ground wire. Probably a sensor wire of some sort. You won't know if that solved anything until you run the engine again. As for the principal ground wires, you have a ground wire running to the firewall from the UIM and you have one down at the bottom, left-side of the engine near the coolant drain plug. Check to be sure they are scuffed free of corrosion and crud, and seated tight against bare metal.
Last edited by getgone; 12-22-15 at 11:01 AM.
#17
I'm only asking questions
iTrader: (6)
Double check the vacuum hose going to the MAP sensor is sound. It would also be quick and easy to try another MAP sensor if you have one to see if the problem follows the part.
I base this suggestion on the description of your problem going from high pressure to vacuum.
With a faulty MAP sensor or vac,/pres. source it could cause some issues you're having.
Plus it's an easy and inexpensive part to swap. (I hate to just swap parts... Always troubleshoot based on reason. )
I base this suggestion on the description of your problem going from high pressure to vacuum.
With a faulty MAP sensor or vac,/pres. source it could cause some issues you're having.
Plus it's an easy and inexpensive part to swap. (I hate to just swap parts... Always troubleshoot based on reason. )
#18
Double check the vacuum hose going to the MAP sensor is sound. It would also be quick and easy to try another MAP sensor if you have one to see if the problem follows the part.
I base this suggestion on the description of your problem going from high pressure to vacuum.
With a faulty MAP sensor or vac,/pres. source it could cause some issues you're having.
Plus it's an easy and inexpensive part to swap. (I hate to just swap parts... Always troubleshoot based on reason. )
I base this suggestion on the description of your problem going from high pressure to vacuum.
With a faulty MAP sensor or vac,/pres. source it could cause some issues you're having.
Plus it's an easy and inexpensive part to swap. (I hate to just swap parts... Always troubleshoot based on reason. )
#19
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Join Date: Apr 2015
Location: Perth, Australia
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Mine had a similar problem. My mechanic found that on the dyno and monitoring the temperature sensor that it was reading erratically -20 to 90c. Something worth checking, does power fc have logging capability?
#20
Yes, it does but I will need to purchase a datalogit. I assume you are referring to the water temp sensor. I have a water temp gauge and it seems to keep a stable normal temp, no erratic jumps. However, I will keep my eyes open in case I missed something. Thanks for the suggestion.
#21
Rotary Enthusiast
^ I'd assume he's talking about the iat sensor , which will add / remove fuel based on the temp of the the intake air. If it's faulty it will compensate with the incorrect amount of fuel
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