Got a 1998 Honda Accord with 220k miles. Its a manual with 2.3 4 cylinder. I am having trouble with performance on cold starts. When I start it in the morning it starts well, but when begining to drive it bucks really bad, like it has run out of gas or fire for brief second then jerks forward and then dies a bit and then jerks forward again. It does this for about maybe 20 minutes. After the engine heats up it wont do it again until it completely cools down.

I have also notice poor fuel economy 17mpg city. Although I am not sure if it is related.

Also I have check engine light on a p1491 EGR code. I have pulled the Egr and cleaned it spotless, but an not sure if it is working as the code has returned. I am not sure it this has anything to do with the cold performance problem or not. Here are some of the things I have done: replaced spark plugs, wires, air filter, pcv, sefoamed intake/injectors, italian tune upand cleaned EGR.The car runs great at idle and at all other speeds.

I am leaning at replacing the EGR valve, but notentirely convinced that this is the culpret. I have thought about blocking it or just pulling the connnector and see if this makes any difference. I dont know how the EGR valve work internally as it is controled electrically by what I assume to be an electromagnet? It is an on off or does the CPU vary the opening?

Would the EGR affect the performance during cold startup? If not, what direction might I go? Thanks for the help.

 

Welcome to the site!
https://www.hondaaccordforum.com/Sti..._128656/tm.htm

P1491 = EGR valve insufficient lift.

Block it off for test, its supposed to be CLOSED at idle. Test only, dont leave it that way.

 

Well I diconnected the egr. No change. Still bucks when cold. You guys think maybe it could be a temperature sensor? I am at a loss.

 

Insufficient EGR lift means the ECU commanded EGR to open but did not detect a corresponding movement of the EGR valve (lift). There is a sensor on the EGR valve that provides a signal proportional to valve movement. This could be a wiring, connector, failed sensor, loss of vacuum to EGR actuator diaphgram, or valve stuck closed or open.

Suggest removing and cleaning valve carefullly, check wiring/connector for damage, check vacuum lines, verify that valve can be actuated w/ vacuum to move smoothliy open and close (spring return). Reinstall EGR valve, reset ECU, and see if code returns. If code returns, the valve sensor is probably bad. You could also download the 94-97 Accord manual to get the complete diagnostics for this fault code. This should be fine for a 98 model. Check Online Manuals in DiY section.

good luck

 

I've cleaned the EGR, but not the intake ports. Was worried about getting gunk in the intake and valves. The codes returns. It is not actuated by vacume. It has an electrical plug that I suspect has a sylinoid on it to open and close it. If there is a sensor nearby, where would it be located? I disconnected this egr when cold, but the engine acts the same.

I guess the real question is would a bad egr system give the bad running when engine is cold? I would have thought the egr would be closed at startup until the engine warmed up. Therefore EGR is not the problem, even though it may be bad or sensor bad. Would it cause the bucking? Almost like running out of fuel then regains fuel. Could be spark as well, but just feels like it would snap you head off at slow speads.

I also though about IAC maybe. But not sure if it has one. Thanks for the help.

 

Just a thought ..... dry gas?

 

Only way to know for sure is to fix the EGR and see if that resolves your symptoms. If EGR valve is solenoid driven open and spring-closed, then the solenoid may be open causing the code. Try applying 12V directly and see if valve opens/closes correctly. The bucking could be caused by EGR valve sticking open.

It may be the bucking problem is unrelated to EGR code, but trying to diagnoise one problem while another is known to exist doesn't make sense.

good luck

 

Thanks Tex for the sugguestions.

The valveis normally closed when cold or at idle. Spring is strong and closes well as I can tell. I've diconnected it therefore causing it to be closed by default. Cold start, no exhaust gases because it is disconnected. Therefore it cannot open. Still has bucking. Thats why I am hesitant about replacing it. If it is suppose to open at coldtemperatures, I might say yeah bad egr valve. The wiring has like 4 or 5 wires going to it and do not know if it is 12volts or less or varies with temp or engine speed. Is the EGR controled by ECU? Using what sensor?Dont know which pinvaries voltage. Thought I'd try to get my fingers on the shaft and feelit rise or lower when it is cold or warm or at different rpms.Still looking for a 98 service manual. All I've found is 97 and below. Its a different EGR system.

My gut feeling is that it is not an EGR problem, but if it is perhaps the egr sensor issending the ineficnet flow code toECU and ECUmay be trying to compensate for the"failed" egr opening by dumping fuel or reducing timing or whatever. I doubt ECU is that intellegent though.

The check engine light has been on for a while. I've bought it that way. PO said it was something to do with emission and not to worry about it. I assumed a O2 sensor, but millage was good until a few months ago. Now 17-18 city driving.

Is the senor for the EGR on the top of the EGR or somewhere else? Anyone know where I can get a service manual for 98?

Thanks.

 

If you go to the online manuals thread in DIY section, the spoonhonda link has a shop manual for a 98-02 accord. I don't think it is for the USA model, but it should be pretty close.

 

I have not found any 98 manuals on any of the sites listed in DIY. I'll keep searching.