whiteboy9191

Okay so I just bought this del sol off a guy a week ago. It seemed a little sluggish but it had been so long since ive driven a honda I just thought it was normal. Then the CEL came on threw code 1, replaced o2 with denso, reset ecu, still ran sluggish and CEL still came on. checked it and sure enough code 1. I should mention that when the CEL comes on it runs absolutely terrible. Also, if I shut the engine off and turn it back on, the CEL is off and it runs okay (still sluggish just not as bad.) Until the CEL comes back on.

The only diagnosing I have done so far is checked the wires and plug that the o2 sensor plugs into. I didnt trace the wires back very far but they seemed fine and the covering around the wires looked as if it had never been messed with.

My next step is to check it with a multimeter I know. After researching a little bit I found multiple threads where they had the same problem and diagnosed all they could and never found an answer. I just figured I would post this up and hope maybe someone who had the same problem can help me out. In the mean time I will be checking it with a multimeter then who knows where I will go from there. Any help is greatly apprecited. I will keep you posted

Former User

Code 1 can also be thrown due to a fuel system problem.

Have you replaced the fuel filter or measured the fuel pressure or tested the FPR?

whiteboy9191

I have not, that will be my next task today after checking the o2 sensor. Thanks for the input, ill be posting later with an update

delsolintegra

Same thing happened to my 93 del sol si D1676 auto. Turned out it was a hairline crack in the exhaust manifold just to the right of the o2 sensor. It was so small you couldn't see it unless you took the exhaust manifold off the engine. It was enought to throw off the sensor's reading and throw a cel light. You couldn't hear it either. I heard it's common for the manifolds to crack. I replaced it with a $60 ebay header and said what the hell and put on a CAI. I think my mileage got a little bit better too. Haaaa.

whiteboy9191

Might be what I end up doing. I just replaced fuel filter still get code 1. Now im gonna check all things that could be causing it, FPR, fuel pressure, and check o2 sensore volts and o2 sensor heater. If all that checks out, headers it is. Thanks for the replies people

Former User

I don't think a cracked header is a good fit with the issue.

A cracked header would make the engine run rich. In general, running rich would not cause an immediate performance problem like you are seeing.

whiteboy9191

So was yours running bad as well? And doing this did fix it, made it run right and stopped throwing code?

whiteboy9191

What would? Like I said I am going out now to check the fuel pressure, o2 sensor, and FPR. But do you have any other ideas that may be useful?

Former User

A lean not rich fuel problem would cause the problem you are having. Continue forward with measuring the fuel pressure and testing the FPR. Also check for clogged fuel injectors or fuel sock on the fuel pump.

whiteboy9191

So you recommend skipping the o2 sensor check?

Former User

Didn't you already replace the O2 sensor with a new OEM one?

What test/check did you have planned?

whiteboy9191

Yes I did, but I was going to check the sensor output signal voltage and measure the resistance of the oxygen sensor heater (as explained in the haynes manual). I read on another thread with similiar problems someone recommended doing this they said just because its a new sensor doesnt mean its not defective. I suppose I should just continue with the fuel supply for now and return to this if all else fails.

Former User

You have code 1. Code 41 would be thrown if the heater was the problem -- no need for any heater tests.

A simple test to see if the O2 sensor is causing the observed performance problem is to unplug it. If the engine runs better, then the O2 sensor is bad, though I doubt it's your problem.

whiteboy9191

okay thanks again man, I will be posting back after I check the fuel pressure. First I need to get a fuel pressure guage and the adapter to use it.

whiteboy9191

Okay fuel pressure guage is on its way to my closest parts store, should be here tomorrow morning

whiteboy9191

Advanced auto cant seem to find the fuel pressure guage I ordered. Luckily my buddy has one I can use but I wont have a chance to work on the car until monday. I was reading in the haynes manual and it mentioned that a crack in the air filter tube would cause it to run lean. could this be related to my problem. I did check out the tube (stock) there doesnt seem to be any cracks or holes.

whiteboy9191

My fuel pressure was in-between 30 and 31 at idle with vacuum hose on FPR attached. Only went up to 40 when vacuum line disconnnected. Also I pinched the fuel return line shut with engine running and the fuel presssure jumped up to 80 in an instant. This is telling me to replace the FPR...Am I right?

Former User

The fuel pressure and FPR seem okay.

whiteboy9191

pressure was okay on those tests, but the haynes manual says to pinch the return line shut and if the pressure rises sharply replace the FPR

Former User

Never heard of this^

Maybe someone else can chime in.

I'd fully expect the pressure to rise sharply if the return line is pinched.

whiteboy9191

If not the FPR then what is my next step? Injectors?

Former User

Yes

whiteboy9191

Well looks like I'll be doing that tomorrow. Thank you for helping

whiteboy9191

Listened for clicking from each injector while engine was idle and they all were clicking. Pulled connector off one by one and engine idle went down the same each time. Is there anything else to do to check them? Because this is as far as the Haynes manual goes for checking them

whiteboy9191

Okay so I replaced the FPR just to see. Still runs bad. But, the fuel pressure guage now reads like 26-28 with vacuum line attached, take it off and it only goes up to about 37-38. So now whats your suggestion people? Or just RonJ@HT since youre the only one helping me. Keep in mind that the fuel filter is brand new and now so is the FPR. Im thinking pinched or clogged fuel line, or possibly clogged filter on the fuel pump itself. What do you think?