Intermittent hard start issues
#1
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Intermittent hard start issues
I have an Intermittent lengthy start issues. Sometimes the car fires up in less than 2 seconds of cranking, other times I can crank for 10+ seconds plus before it'll fire.
When the motor was out, I cleaned all injectors, MAF sensor, everything in and on the intake manifold was cleaned and I did a slight port/polish job on the intake manifold runners. Upon installing the motor, we could not get it to start initially for a while. We finally got it started with a pop start, and it would run fine until idle dropped down to ~1000RPMs and then it would stall out. after a while, we ended up finding the throttle plate was all sludged up, after cleaning the throttle plate it started and ran fine until about ~700 miles into the break in (probably only the 4th or 5th drive, I drove it a lot to get it broken in), where I started getting the intermittent hard start, cold or hot engine didn't matter. It starts hard probably 25% of the time, and I am running out of ideas as to why. When it does start hard, it smells extremely rich, like eye watering rich. so I am thinking it is a start up fuel issue, but that can't be adjusted with COBB. Car currently has about 1700 on the rebuild.
Some brief history:
Rebuilt engine with an Atkins rebuild kit and a heavy port job.
Blows 90-95psi on all 6 faces when cold.
Blows 110-120psi on all 6 faces when hot.
^^Both of those numbers are with a piston compression tester with no schrader valve.
BHR ignition.
Racing beat dual resonator midpipe.
AEM intake.
Cobb tuned with BHR dwell tables.
13 tooth starter.
Newer battery.
Some other things I've tried/checked:
Fuel pump filter is the original but clean.
Fuel pump primes and pressurizes fine. I haven't actually checked the pressure but it definitely builds pressure.
Fuel pump check valve seems fine.
I went out and bought a brand new OEM ignition/wires thinking the BHR ignition was the cause. It didn't resolve anything.
Stock dwell settings on BHR coils doesn't help.
Stock tune doesn't help.
Throttle plate is clean.
Grounds cleaned.
MAF is cleaned and scaled.
Any help would be greatly appreciated!
When the motor was out, I cleaned all injectors, MAF sensor, everything in and on the intake manifold was cleaned and I did a slight port/polish job on the intake manifold runners. Upon installing the motor, we could not get it to start initially for a while. We finally got it started with a pop start, and it would run fine until idle dropped down to ~1000RPMs and then it would stall out. after a while, we ended up finding the throttle plate was all sludged up, after cleaning the throttle plate it started and ran fine until about ~700 miles into the break in (probably only the 4th or 5th drive, I drove it a lot to get it broken in), where I started getting the intermittent hard start, cold or hot engine didn't matter. It starts hard probably 25% of the time, and I am running out of ideas as to why. When it does start hard, it smells extremely rich, like eye watering rich. so I am thinking it is a start up fuel issue, but that can't be adjusted with COBB. Car currently has about 1700 on the rebuild.
Some brief history:
Rebuilt engine with an Atkins rebuild kit and a heavy port job.
Blows 90-95psi on all 6 faces when cold.
Blows 110-120psi on all 6 faces when hot.
^^Both of those numbers are with a piston compression tester with no schrader valve.
BHR ignition.
Racing beat dual resonator midpipe.
AEM intake.
Cobb tuned with BHR dwell tables.
13 tooth starter.
Newer battery.
Some other things I've tried/checked:
Fuel pump filter is the original but clean.
Fuel pump primes and pressurizes fine. I haven't actually checked the pressure but it definitely builds pressure.
Fuel pump check valve seems fine.
I went out and bought a brand new OEM ignition/wires thinking the BHR ignition was the cause. It didn't resolve anything.
Stock dwell settings on BHR coils doesn't help.
Stock tune doesn't help.
Throttle plate is clean.
Grounds cleaned.
MAF is cleaned and scaled.
Any help would be greatly appreciated!
#3
Zoom-Freakin'-Zoom
iTrader: (5)
throttle plate?
you cleaned the injectors?
send out injectors for cleaning.. you cant really clean them.. and replace the fuel pump.. that is where the dirt that clogged the injectors came from.
btw, i have that 3 second skip before my car starts, it is the low speed injectors clogged.. hot or cold.
beers
you cleaned the injectors?
send out injectors for cleaning.. you cant really clean them.. and replace the fuel pump.. that is where the dirt that clogged the injectors came from.
btw, i have that 3 second skip before my car starts, it is the low speed injectors clogged.. hot or cold.
beers
![Beer](https://www.rx8club.com/images/smilies/beer.gif)
#4
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Throttle body and whole intake manifold including injectors were coated with a black gunk (oil/carbon mix probably) when I got it. I cleaned it all out before the motor went in, except the throttle body. Ended up biting me in the *** when we tried to get the motor running originally. There was 1/16-1/8 of gunk on the whole thing, not allowing it to get air at idle or start up. The injectors were cleaned and pulse tested. They were not flow tested though, I guess I should do that. Low speed injectors are the red ones on a 6 port, right? As for my fuel pump/filter. It was and still is clean.
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