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Your ECT sensor tells the computer the engine’s temperature during a start. A colder engine needs more fuel to start. On some vehicles, a bad ECT will tell the computer the engine is below 0 F. When this happens excess fuel gets dumped into the cylinders, causing something that resembles flooding.
Your ECT also tells the computer how warm the engine is when idling. There may be an idle adjustment for temperature.
Your TPS tells the computer whether you’re pressing down on the gas pedal, and so therefore whether the IAC needs to open.
In other words, both of your codes could cause the symptoms you’re seeing. Fix those codes, then chase what’s left.
[quote=”hnemelka” post=187357]When the car is stopped and in neutral, the car no longer vibrates. As soon as the gear is shifted into drive (with the foot on the brake), it begins vibrating again.[/quote]
What is the engine RPM in each case?
The actual EGR valve does work. I can put a little suction on it and it will all but shut down the engine if I keep it open a little. I’ve also replace its solenoid valve but I’ve never been able to detect any application of vacuum to the EGR valve while driving once operating temperature was reached. I put a T in the vacuum line to the EGR valve and ran a line from that to a gauge that I taped to the windshield. No vacuum was ever indicated once normal temperature was reached. I checked for kinks, too.
You mentioned some attempts to find a vacuum leak. A vacuum leak can also be diagnosed by looking at fuel trims with an OBDII scanner. What do your long/short fuel trims look like:
– when idling
– at > 3000 rpmA lean condition (> ~10%) at idle that decreases as the throttle opens is consistent with a vacuum leak.
You can track a vacuum leak cleanly by releasing propane gas with an unlit torch in the vicinity of the suspected leak. Decrease in short term fuel trim means you got some propane into the intake.
How do you know that what you’re hearing is in fact lifter tick? For example, could the noise be due to something other than the lifters?
If the IAC is somehow stuck in a closed position, that could prevent your car from starting by depriving the engine of oxygen while the throttle is closed.
There are two ways to test this idea:
1. open the throttle while cranking
2. pull the brake booster hose without opening the throttleEither one should bypass the IAC and allow air into the engine to start it. Then you could go about diagnosing an air delivery problem during start.
If your car doesn’t start with these tests then it’s possible that something else changed during your IAC swap and re-swap. So you should diagnose and fix that problem.
Either way, take out the part you bought and replace it with your old one before testing.
So I did my checks everything is good so I check the plug on the back of the coil pack. No power to that.
Do you have a wiring diagram? If so, this should let you trace back from the coil pack to the PCM looking for opens and shorts.
Also, the tail pipe almost always has droplets of water spitting out at idle. I’m pretty sure it’s coolant, because it has a sweet smell to it. Is there anywhere else internally I could be losing coolant that wouldn’t show up on a leakdown test? (That is. if it turns out I can’t find any external leaks with the pressure test).
I’m not sure about your specific vehicle, but the idle air control valve on many Hondas has a coolant jacket separated from the intake by a ~1/4 inch gasket. If that gasket leaked, you’d suck coolant into your intake. You might try smelling and looking for coolant in your throttle body or intake manifold. Or you could inspect the IAC gasket itself.
Oddly enough, I’m seeing 1.3 volts on my scan tool even with the O2 disconnected.
That sounds consistent with a problem in the O2 sensor circuit. It would be either a short or a problem with the PCM. Either way, the O2 sensor has nothing to do with reading 1.3 volts because it isn’t even connected.
On Civics from that era, the FSM gives this procedure:
With the O2 sensor disconnected and the key in the OFF position, remove the 4 pin primary O2 sensor connector and check for continuity between sensor terminal 1 (positive sending) and ground. If there is continuity, repair the short. If there is no continuity, replace the PCM with a known good unit and re-check.
You might check the service manual for your car to find the diagnosis procedure.
We sprayed starting fluid in throttle body and ran for about 5 secs.
That’s a strong clue you should be chasing a fuel problem. You did some preliminary tests. Here are some additional ideas:
– Measure fuel pressure with key in the KOEO position. How does it compare to spec? Remove the key and let the car sit. How much does the pressure drop after 1 hour? Your pump could be working fine, but delivering insufficient fuel pressure. Leakdown could indicate a fuel leak somewhere.
– Listen to injectors while starter cranks (stethoscope or screwdriver). Are they clicking?
– Check for power/signal at the injectors while cranking? Use an LED test light (or maybe power probe?).It looks like the bolt threads into solid metal but it instead threads into a nut factory welded to the interior of the frame. When that nut breaks loose, the bolt will spin as you describe. There is no obvious access point to this nut, so once it breaks loose, you’re no longer dealing with a standard repair.
But if you search very hard, you’ll find dozens of cases of this problem – with few good solutions reported.
The problem is made worse by trailing arm bushing repair videos that recommend unbolting the suspension via the upper control (camber) arm. That puts stress on the bolts/nuts and makes it likely you’ll cross-thread or worse. Far easier to leave the camber arm bolted and disconnect it from the trailing arm through its one connecting bolt.
The interior nut on my car broke loose. I took the car to about six shops. The solutions ranged from completely unworkable (helicoil) to outlandish (major frame surgery) to pathetic (dealer who said the problem was unrepairable).
Finally found a shop who would do the work. They replaced both bolts. I’m not 100% sure how they did it, but now the thread of the bolts points outward and a nut threads down on each one. I suspect magnets were in involved in threading the bolts through the frame. The shop claims the gas tank was dropped, but (a) there’s no obvious way how this would aid the repair; and (b) the repair was completed much too quickly for the tank to have been dropped. Either way, the repair has lasted several thousand miles and is still going strong.
The next best alternative I’ve found is to use rivnuts:
https://www.ek9.org/index.php?threads/do-most-eks-have-this-problem.18958/
However, the durability of this repair is an open question.
Good luck, and if you get this fixed, it would be nice to know how it was done and its durability.
First things first – does the engine crank?
My fuel pump works and I have fuel pressure all the way up to the banjo bolt on the fuel rail.
What pressure did your gauge show? What did it read as you cranked the engine (assuming it does crank)? You can hook a fuel pressure gauge to the banjo bolt on the fuel filter. Don’t rely on seeing fuel after loosening the bolt, which will mislead you if your pressure is weak.
What are my next steps in diagnosing the problem?
For a cranking no start, you can use a tried-and-true method called FASTTEC to systematically rule out possible causes: