Hey guys, I'm needing a little help. I have a 1998 Accord LX Coupe V6 that is intermittantly sputtering at low-mid RPM range. The motor feels like it is going to die, then it catches and throws you back in the seat trying to get moving again. If I floor it, it will down shift and run awesome. I'm at a loss, I can't get this figured out. If I shut the car off and cycle power, it seems to go away. I started getting maintenance caught up to keep the car dependable and here's where I'm at. I have recently changed / cleaned / replaced the following parts...

Plugs, wires, cap, rotor
IAC Valve
TPS
MAP Sensor
EGR Valve
EGR passageway cleaning (not the kit, just cleaned the ports out)
timing belt, waterpump
fuel pump
fuel rails, and injectors
fuel pressure regulator
transmission fluid dump/fill

I hope someone out here can help. I have a 26 mile commute one way and it can get annoying having to pull over and re-start the car as mine will not start in neutral.

Thanks in advance guys

 

Oh, yes and the car also has a new PGM/FI relay

 

Low/mid rpm range problem suggests EGR is possibility. Suggest disabling EGR to see if problem is fixed (plug vacuum actuator line to EGR valve).

Shop manual suggests for low power symptom to 1) check fuel pressure, 2) Inspect/test throttle body, 3) Inspect/adjust throttle cable.

Check engine light is never on?

Your final paragraph suggests car actually dies while driving and you must pull over/stop to restart. Not being able to start in N is a fault of the transmission range selector switch.

good luck

 

I will look into the transmission range selector switch. I was originally thinking EGR, but I have cleaned the EGR passages and the car has a new valve. I would plug the vacuum line to it, but it only has the wiring connector, nothing else. I have since found a defective IAT sensor, but that didn't take care of it either. The issue is getting worse and I am beginning to think computer.

The car has not yet completely died due to the issue, but it is nearly impossible to drive when the issue gets bad

 

Also, can someone confirm something for me? Does the PGM/FI relay provide both the fuel pump and ECM/PCM with power? The reason I ask is the whole car acts like it's losing power (both electrical and horsepower) at the same time, then it will catch and go, then repeat the issue. I was womdering if the PGM/FI relay could be the culprit. I have replaced it, but I put one in from Autozone, I wonder if it has a weak coil in one of the relays

 

That main-relay provides power over 2 different circuits. It's actually 2 relays together in 1 plastic case. (for the couple model years I'm familiar with, including 1998)

- one relay switches power on to the PCM itself, as well as a lot of sensors & solenoids associated with the PGM/FI system. I can't think of anything on this circuit that's outside the realm of the "fuel-supply" system.

- the other relay switcher power to the fuel pump, when that relay is energized by the PCM.

Nothing else is switched through it, so no radio, windows, lights, etc. Not even the coil/sparkplugs are powered through the main relay.

 

That's exactly what I needed to hear. The issue that I am having is like the car is losing fuel and power (horsepower or electrical to the computer). The lights, radio, clock, gauges, etc. all work flawlessly. I replaced this relay with a cheap aftermarket one about 6 months ago, so I am wondering if it has a weak coil in the relay. I have seen some relays mimic this symptom on other things when they had a weak coil (I work on residential HVAC systems). The relay is under warranty, I am heading to the parts house to get another afterwork (under warranty), if it works, I'll find a better quality one to put in permanently. Thanks Jim.

 

Well, unfortunately whatever the issue was finally killed the car. I was in a friends driveway and the engine suddenly caught fire while idling. When the fire broke out, it manages to split the fuel lines and sprayed gas over the flames. Once I got the fire out, the car was totaled. Thanks for all of your help guys, I appreciate it.