Someone else advised this as well, but again, there is a BRAND NEW CAT on the car and there are NO VACUUM LEAKS.

Saturday, however, I was putting the new suspension on because I already had it and was bored and decided to check my fuel pressure again. This time it was at 31-32psi and would not come above it. I'm going to replace the fuel filter with a Hi Pressure/Flow AEM and the fuel pump with a walbro 190lph. Hopefully, AND I MEAN HOPEFULLY, this just might be it...

 

i think 32 psi is ideal for fuel pressure on hondas.

 

From what I've found you should be about 38-41psi. Either way, replacing the entire fuel system this weekend (fuel pump, fuel filter, injectors, fuel rail, fpr). We shall see.

 

It's amazing what you can do to a car and see absolutely no difference. Also messed with the "Air Injection" line, but that wasn't it either. May be purchasing another ECU...

 

Fuel system didn't fix anything. However, a Honda Tech told me to check the "air injection" line. I did not know about this and sure enough it was clogged BUT did not fix the problem either. So, what the problem is not as it has been replaced:

• Upstream O2 Sensor
• Downstream O2 Sensor
• Catalytic Converter
• Coil
• Distributor
• Spark Plugs
• Plug Wires
• Distributor Cap & Rotor
• Fuel Pump
• Fuel Filter
• Injectors
• ECU
• MAP Sensor
• Air Temp Sensor
• Timing
• Battery
• Ground Connections

What is left besides the damn engine to replace?!?!?!

 

Have you done a leak down test both cold and hot?

 

No, only when it was cold. I don't remember the numbers but they were fine. I only did it cold because that's when it has the problem. When the engine is warm, it drives just fine.

 

ignition control module

 

My bad, that should have been included on the list.

• Ignition Control Module

 

I'm trying to pick up another set of injectors to see if the ones that I got were also bad. After reading A LOT on this, I'm thinking they could still be the issue, but at this point I'm half tempted to light the damn thing on fire!

 

OP


I havent read all 2 pages of posts but have you done

Leak down test
Compression test
Both cold and operating temps?


I have a hyundai sonata in the shop with the same issue right now. Been here 3 times. I did a leak down while cold and it was 20 percent on cylinder 1 and 4.
Compression results was #1 130 #2 180 #3 185 #4 110

 

so you did replace the grounds for the motor? i'd check again for any stored codes. if there's none, next step would be a leakdown and compression test in my book. godspeed man, lol we've all been there.

 

Yes I have done leak down and compression tests when the motor was cold, not at operating temps because there is not an issue at operating temps. The grounds were double and triple checked and then replaced JUST to be sure. There are no stored codes. Haven't gotten the 3rd set of injectors yet, so I'm still waiting on that.

 

New set of injectors did not fix it either.

I'm going to try 2 things and if they don't fix it, it's going up for sale.

 

ok so i read through the whole thread, and you havent mentioned checking ignition or cam timing....having the distributor all the way retarded or advanced will make the car run like ****. also if your t belt jumped a tooth its possible you didnt hit a valve and it will also run like ****. GO CHECK EM OUT
my guesses are either timing or ecu! good luck hope you figure it out

 

Actually I mentioned timing on the list of the things. Its timing is right on, plus that would make it run like crap all the time, this is only when it's cold. The entire ignition system has been replaced at this point and I have swapped out ECU's so that's not the issue either. I'm replacing the T Belt sometime this weekend most likely just because it probably hasn't been done before, but when it was checked, it's TDC with the one that's already on the car.

 

In my experince it's likely to be something simple and/or dumb. like wires that are loose or eaten by rodents. all of the issues/codes could be related to the wiring harness it seems.

We had an Integra towed to the shop a few years back that had some similar running issues; ran like crap under normal conditions. when it warmed up and you pushed it it had full power and everything seemed great. turns out a sloppy head rebuild left the VTEC pins locked at all times. maybe not your exact issue but keep weird crap like that in mind. it may help.

 

We've gone through the harness and haven't found anything that is out of the ordinary and all signals are making it to the ECU with the correct resistance. I haven't pulled the engine apart but about to either buy another motor, sell the damn car, or strip it down and put everything back together piece by piece...

 

Not sure if its been checked or replaced, but the coolant temp sensor plays a huge role in fuel management and i have seen them cause drivability problems. Id be interested to see what the datastream looks like cold vs hot and while the problem is occuring. If you havent ruled out coolant sensor and want to check it, assuming you have a voltmeter, i can get you the specs you need to check it

 

The coolant temp sensor is working fine. The problem is happening when the ECU is in open loop because it's cold, so it has nothing to do with the O2 sensors or many other sensors as they don't play a role until the car is warm and in a closed loop. I'm thinking this is probably more mechanical than electrical at this point. I have a gut feeling it's either a head gasket and/or warped head. It could be just small enough to pass leak down/compression (within reason for this old of a car) but just big enough to leak a little under load when it's cold and hasn't expanded yet. We may adjust the valves this weekend, but I'm already looking into buying another head and just building it a little (cam, springs, valves, valve guides, ti retainers.... the basics)

 

good luck!

 

You will not be misfiring on all 4 cylinders with a slightly had headgasket.

Sounds like something ignition related. What components have you replaced? Wires, plugs, rotor, cap?

 

Actually, it's just cylinder 3, but once a single misfire is "recognized" then all four "misfire". The entire ignition system has been replaced... ALL OF IT.

 

How are you sure that the coolant sensor is working properly? Ive seen them do very weird things and heard many stories of odd issues when they act up. Do you have a scanner or access to something with a datastream?

 

My scanner doesn't do live stream. However, the voltmeter showed correct voltage (according to the tech)