2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

engine acts blown, but isn't. Or, maybe it is?

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Old Sep 11, 2013 | 09:10 PM
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Unhappy engine acts blown, but isn't. Or, maybe it is?

So here's the latest and greatest problem with my car:
Car was running perfectly fine, I took it took the car wash, parked it at a friends house maybe a minute from there. My problem started when i went to start it back up maybe an hour later, it turned over particularly easy but tooka while to start( it normally doesnt turn over so easy for whatever reason it takes a few tries to get the starter to engage, but starts quickly once it does), it didn't want to hold an idle for a while and when it did it settled in at 500rpm instead of the usual 850rpm, it had slight powerloss down low but cruising seemed to be fairly normal, however in boost the car runs like garbage and has no power. I did a poor mans compression test and got 3 even strong pulses from both rotors. coolant looks clean. oil looks clean. exhaust doesnt smoke. My AFR's are slightly richer than normal and i am getting backfire on decel now and then which i normally wouldnt. what's the issue here?

my setup: s4 6-port turbo: greddy 20g turbo kit, fmic, msd 6a, removed emissions, external waste etc, at 13psi running rtek 2.1 ecu, using aghrx 9.4 compression timing maps but even slightly more conservative. walboror 255 uel pump, aem AFPR, 900/1600cc injectors, innovate wideband, i premix 1 1/2 oz oil per gallon gas, always run 93 octane. never see boost creep, my afr's are consistently in the 10's and low 11's at full boost. motor has probably 25k miles, stock ports.

I know idle is a sign of a blown engine and hard starting and power loss BUT i've had a blown turbo engine before and the only time it actually made ANY power was under boost. not under cruising. when i checked my plugs they were a little dark but didnt look that bad at all. cleaned up real easily. could washing the car have shorted something out? or anything have shorted to cause symptoms like this?

I did everything right with this build. i've only driven it like 1000 miles on this turbo setup. it's my third engine in this car. SO any ideas besides "do a real compression test" would be greatly appreciated. i cant heart another blown engine.
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Old Sep 11, 2013 | 09:33 PM
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sbrmechanic's Avatar
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Ive heard of very weird symptoms coincidentally happening after car washes before, not sure what it could be, but i wouldn't worry about a blown engine
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Old Sep 11, 2013 | 09:36 PM
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I need to do a compression test then go from there. Just hearing pulses wouldn't indicate a partially blown seal.
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Old Sep 11, 2013 | 11:00 PM
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you got electronics wet...
happens all the time..take a hair dryer to whatever connectors,ETC that you can see..


PS; bucket and sponge the next time..!
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Old Sep 12, 2013 | 12:16 AM
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Originally Posted by VANHALEN
I need to do a compression test then go from there. Just hearing pulses wouldn't indicate a partially blown seal.
****... "You"
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Old Sep 12, 2013 | 05:54 AM
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I had 3 strong sounding, even pulses with a blown engine. They were 3 at around 30-40psi
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Old Sep 13, 2013 | 04:33 PM
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i always sponge and bucket my car, it was just a little dirty from a dirt road i took so figured id spray it off at the selfserve carwash... you could very well be right, though i don't think the cra saw much more water than it would have with the hose at home.

I realize the car COULD still have poor compression even while audibly even. BUT! i don't want to think about that being a possibility right now. ALSO I've driven blown rotary engines before, while it has many of the same symptoms, it just doesn't act like a blown engine.

with lots of digging, it sounds like a failed leading coil. or it could be my msd 6a failed causing it to act like leading coil failure.

I have plenty of spare coils and ill actually have a chance to work on it sunday, so we'll see how things go then. regardless, thanks for the advice guys!
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Old Sep 18, 2013 | 09:13 PM
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Found the problem! not a blown engine! my msd 6a ignition box had failed causing my leading coil to act failed. disconnected the msd and the car runs great again!
So for future reference. an fc will run on just trailing ignition just like **** and bad leading coil will cause blown engine like symptoms!
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Old Sep 18, 2013 | 09:24 PM
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glad you fixed it bro, I bet you're happy it was just something stupid.
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Old Sep 18, 2013 | 09:28 PM
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Originally Posted by Templeton
Found the problem! not a blown engine! my msd 6a ignition box had failed causing my leading coil to act failed. disconnected the msd and the car runs great again!
So for future reference. an fc will run on just trailing ignition just like **** and bad leading coil will cause blown engine like symptoms!
Lesson learned.
Invest in a compression tester. Would've saved all your worries.
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Old Sep 18, 2013 | 10:52 PM
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Originally Posted by misterstyx69
you got electronics wet...
happens all the time..take a hair dryer to whatever connectors,ETC that you can see..


PS; bucket and sponge the next time..!
What kind of ***** car can't take some incidental water spray without flatlining?
Could such a car run in a moderate rainstorm?
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Old Sep 24, 2013 | 06:38 PM
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Very glad it was something stupid. I built the car right so for it to have blown up so quickly would have made me totally lose faith in rotary's.

It wouldnt have saved me all the worry, I had to leave it sitting for a few days regardless from being so busy at work and school. I do have one, just not rotary style it's a pain in the ***.

the MSD 6A was the water *****. not the rest of the car.
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