91 prelude no start mystery
02-10-2018, 04:49 PM
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91 prelude no start mystery
1991 Prelude Si 4WS, B21A1 with 200,000+ miles, manual transmission.
So, my problem is that my car cranks just fine, has spark (tested with HEI spark tester), has fuel (can hear fuel pump and can smell gas on each each spark plug), has compression.
The history is the car was running fine but I failed smog (CA) with very high NO. The smog guy suggested a dirty EGR valve might be responsible. When I pulled it it wasn't too bad, some carbon but the diaphragm seems fine and the pintle moves freely. I saw a little carbon in the ports so I used a small wire brush to clean it out and used a shop vac to vacuum it out so it wouldn't get sucked into the intake. I didn't use any cleaners or solvents.
When I started the car the idle was low and a little rough so I turned it off and I haven't been able to get it to start since then.
I replaced the distributor with a better one because all of the sensor wires on the old one were cracked. The replacement is off of the same model car, not an after market part.
Everything is connected, all grounds are good and, as far as I can tell, there is no reason that this car shouldn't start.
Can anybody help me?
So, my problem is that my car cranks just fine, has spark (tested with HEI spark tester), has fuel (can hear fuel pump and can smell gas on each each spark plug), has compression.
The history is the car was running fine but I failed smog (CA) with very high NO. The smog guy suggested a dirty EGR valve might be responsible. When I pulled it it wasn't too bad, some carbon but the diaphragm seems fine and the pintle moves freely. I saw a little carbon in the ports so I used a small wire brush to clean it out and used a shop vac to vacuum it out so it wouldn't get sucked into the intake. I didn't use any cleaners or solvents.
When I started the car the idle was low and a little rough so I turned it off and I haven't been able to get it to start since then.
I replaced the distributor with a better one because all of the sensor wires on the old one were cracked. The replacement is off of the same model car, not an after market part.
Everything is connected, all grounds are good and, as far as I can tell, there is no reason that this car shouldn't start.
Can anybody help me?
02-16-2018, 04:43 AM
#2
Honda-Tech Member
Re: 91 prelude no start mystery
do a valve lash adjustment.
check the timing belt to make sure everything is in time.
check for any stored trouble codes and repair as necessary.
replace the main relay. You said you can hear the fuel pump priming, but it's next to impossible to hear it when the engine is cranking. The main relay is a very common culprit anyway, and will definitely need replacement sooner or later, so might as well do it now.
Put the distributor in the middle of its adjustment for now, and once it's running make sure you go back and use a timing light to set it the correct way.
If the car sat for any amount of time, drain the gas tank and fill with fresh gas.
A proper tuneup may be in order.
Check the power of the coil with a spark tester to determine if it has a strong enough spark. Presence of spark is not always enough to rule out a bad coil or wires.
check the timing belt to make sure everything is in time.
check for any stored trouble codes and repair as necessary.
replace the main relay. You said you can hear the fuel pump priming, but it's next to impossible to hear it when the engine is cranking. The main relay is a very common culprit anyway, and will definitely need replacement sooner or later, so might as well do it now.
Put the distributor in the middle of its adjustment for now, and once it's running make sure you go back and use a timing light to set it the correct way.
If the car sat for any amount of time, drain the gas tank and fill with fresh gas.
A proper tuneup may be in order.
Check the power of the coil with a spark tester to determine if it has a strong enough spark. Presence of spark is not always enough to rule out a bad coil or wires.
03-07-2018, 05:49 PM
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Re: 91 prelude no start mystery
Thank you for your response and sorry I didn't get back here sooner but I have been way too busy with this car. Here is an update of what is going on.
I ended up having it towed to my roommate's "amazing" mechanic, who told me that all of my valves were bent and wanted to do a $1300 valve job, nope. I took it home and tore the head off and found a blown head gasket (exhaust going into the coolant, so, luckily no oil in coolant or coolant in oil) so I sent the head to a friend's machine shop and all of the valves were perfectly fine but he did a valve job anyway for $180 (way better than $1300!). There was no warpage of the block or head and everything else looks pretty good. I am in the process of putting it all back together and am having a hard time getting the timing belt on because it is really tight. Even with the tensioner all of the way down I need about 1/8'' more to get the belt over the exhaust cam gear. Very frustrating.
I will need to rebuild my fuel injectors in the near future and a few other things but as far as I can tell it should start when I'm done, I'll update again when I have something to tell.
I ended up having it towed to my roommate's "amazing" mechanic, who told me that all of my valves were bent and wanted to do a $1300 valve job, nope. I took it home and tore the head off and found a blown head gasket (exhaust going into the coolant, so, luckily no oil in coolant or coolant in oil) so I sent the head to a friend's machine shop and all of the valves were perfectly fine but he did a valve job anyway for $180 (way better than $1300!). There was no warpage of the block or head and everything else looks pretty good. I am in the process of putting it all back together and am having a hard time getting the timing belt on because it is really tight. Even with the tensioner all of the way down I need about 1/8'' more to get the belt over the exhaust cam gear. Very frustrating.
I will need to rebuild my fuel injectors in the near future and a few other things but as far as I can tell it should start when I'm done, I'll update again when I have something to tell.
03-07-2018, 08:23 PM
#4
Honda-Tech Member
Re: 91 prelude no start mystery
nice, glad you got it figured out.
The timing belt can be tricky first time around. To help you out though with one trick; you can lock the cams at TDC to help a bit. On the cam cap closest to the belt, you'll see an eyelet, for both cams. When the cam is at TDC, you can stick a #1 philips screwdriver, or an allen wrench, into that hole and it will drop down into the cam and hold it in place. Just make sure you DO NOT turn the cam with a wrench at all while you have those "pins" in the holes, or it will crack the cam cap. But now you won't need to manually hold them with a wrench. Also, obviously set crank to TDC as well, but then turn it backwards a small hair. This will give just enough slack to get the belt up over the exhaust cam.
And of course make sure everything lines up before rotating the crank, and DO NOT FORGET to remove the "pins" from the cam caps before turning the crank with a wrench either.
The timing belt can be tricky first time around. To help you out though with one trick; you can lock the cams at TDC to help a bit. On the cam cap closest to the belt, you'll see an eyelet, for both cams. When the cam is at TDC, you can stick a #1 philips screwdriver, or an allen wrench, into that hole and it will drop down into the cam and hold it in place. Just make sure you DO NOT turn the cam with a wrench at all while you have those "pins" in the holes, or it will crack the cam cap. But now you won't need to manually hold them with a wrench. Also, obviously set crank to TDC as well, but then turn it backwards a small hair. This will give just enough slack to get the belt up over the exhaust cam.
And of course make sure everything lines up before rotating the crank, and DO NOT FORGET to remove the "pins" from the cam caps before turning the crank with a wrench either.
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