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Engine Idles but won't rev - help plz!!

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Old 07-23-2004, 10:37 PM
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emrysm
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Default Engine Idles but won't rev - help plz!!

I posted here recently, and i'm having a new problem. The car will idle properly now (well, somewhat properly) but sputters and misfires when you rev it up. There are a few things I didn't mention before that might be important. When I put this engine in originally, I tried to start it, and it did start, then made a loud 'hiss' and died. Turns out the combustion chambers were corroded and the rings were seized up. I replaced the rings, honed the cylinders and put it back together, and now we're having trouble getting it running. We have played with the timing quite a bit, and it seems to run best with the distributor turned to _just past_ where the holding bolts let it turn to (towards the front of the car) We have checked all of the vacuum lines for leaks and found none. I have also checked the sensors on the throttle body and they are working correctly. When we put the engine in, I broke of a sensor that is just below the intake manifold and plugs straight into the block - do you know what that is? The only code the ECU throws is 19 (one long blink followed immediately by 9 short ones) which is there because I got rid of the auto in lieu of a manual. I can't figure out what could be wrong! Would it cause this much trouble if my valve timing were off by one tooth on the cam sprocket? I don't think it is... but i'm starting to wonder! What else could cause this? All the sensors worked when I pulled the old engine out.... and now..... This thing is driving me crazy!

please help!
Old 07-24-2004, 12:47 AM
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Jafro
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3 things...

1. Bad or disconnected TPS harness/sensor
2. Wrong injectors/ECU
3. Not getting enough fuel.

The sensor that plugs into the back of the block near the oil filter is teh oil pressure switch.
Old 07-24-2004, 03:10 AM
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92eg6
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check your ground wires. make sure they are all really tight. also if you have a spare ecu check that out. i had a problem similar way back in the day of my 1st swap and my dumb a$$ didnt tighten the ground wireS all the way.

also if your car starts and idles but doesnt go past a certian rpm it could be the ecu stuck in dummy mode. usally a p28 in dummy mode wont go past 4400rpm
Old 07-24-2004, 05:00 AM
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shifty35
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If if runs well with the distributer cranked really far, you may have put the timing belt back on a tooth or two off. If this is the case, check for bent valves when you reassemble.
Old 07-24-2004, 06:39 AM
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honura
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I had that same problem and I had the map sensor plug mixed up with another one. I think the tps but can't remember. there are 2 plugs on your intake mani that have the same plugs make sure there in the right place.
Old 07-24-2004, 07:20 AM
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Jafro
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Originally Posted by honura
I had that same problem and I had the map sensor plug mixed up with another one. I think the tps but can't remember. there are 2 plugs on your intake mani that have the same plugs make sure there in the right place.
Those would be the IAT sensor, and the AICV. You'd throw ECU code #14 with a check engine light, and your idle will sound like... "hondahondahondahondahondahonda". I did that, too. :\
Old 07-24-2004, 11:52 AM
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emrysm
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Originally Posted by Jafro
3 things...

1. Bad or disconnected TPS harness/sensor
2. Wrong injectors/ECU
3. Not getting enough fuel.

The sensor that plugs into the back of the block near the oil filter is teh oil pressure switch.
1 - checked that, tps reads .5V @ closed & 4.5V @ open - just like he's supposed to
2 I did change the injectors over from my other engine, and they ran fine with this ECU, so not this...
3. fuel pressure is good.

the idle is still fairly high (like 1500) but if i disconnect the sensor on top of the throttle body (forgot the name of it), the idle drops to almost normal, but won't stay there unless we hold it at WOT . . . then it just sits at 500 til you let off the gas and it dies.
Old 07-24-2004, 11:55 AM
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emrysm
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Originally Posted by shifty35
If if runs well with the distributer cranked really far, you may have put the timing belt back on a tooth or two off. If this is the case, check for bent valves when you reassemble.
this is quite a possibility - I think it's one tooth off on the cam in the same direction as what I turn the distributor to get it to idle. if I do end up pulling the timing belt, I'm going to replace the head with my old head... we inspected it and it's in good condition.

another one someone mentioned is ground straps. I'm PDS that I got all of them connected right, but I guess I could have missed one. I have a bad feeling it's valve timing....
Old 07-24-2004, 11:57 AM
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emrysm
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Originally Posted by 92eg6
also if your car starts and idles but doesnt go past a certian rpm it could be the ecu stuck in dummy mode. usally a p28 in dummy mode wont go past 4400rpm
what would that feel like? would it idle normally and rev normally then cut off like it has a low rev limiter or what? my engine feels more like it can't get past mid range revs b/c of some mechanical limitation... misfires, sputtering and the like.
Old 07-24-2004, 01:09 PM
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PHiZ
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Originally Posted by Jafro
Those would be the IAT sensor, and the AICV. You'd throw ECU code #14 with a check engine light, and your idle will sound like... "hondahondahondahondahondahonda". I did that, too. :\
Actually from his description it was obviously the MAP/TPS that he swapped.

Don't get me wrong, you can also accidently swap IAT/IACV. That combination can blow ecus too, btw. So be careful.

-PHiZ



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