D16SiHatch

car: 96 ex, z6 swap, obd1 on a p28

So this hasn't been a problem until it's been getting in the 80 degree temperature range as of late. If the engine is warm from either sitting baking in the sun, or because it was ran prior, it will not want to start. It's only just started happening, and i'd say about 1/2 the time it will have an issue starting while hot. I don't believe its the main relay because you can watch the cel, etc come on and turn off like they are supposed to when turning the car to run. Also, what happens is it will crank and crank and crank and eventually begin to start up. It will idle at what appears to be about 100rpm and shake around like a son of a bitch. Giving it gas doesn't help, it just has to sit there and slowly build up rpm. It sounds almost like its not firing on all cylinders as it tries to come up to a reasonable rpm. after maybe 15 seconds or so its now idling properly and sounds just fine. I can drive it and their are no adverse effects whatsoever, it only does this weird **** while starting, and when it's hot. My first thought is some kind of weird vapor lock situation, but i can't imagine it would take that long for fuel to get back into the line and to the injectors.. My other thought is the fuel pump, but why only when it's warm out. i'm at a loss really, i'm not sure what to think, and i don't want to start replacing parts all ***** nilly.

thoughts?

cliffs:
when hot it cranks for awhile and then chugs from about 100rpm up to a normal idle speed.

D16SiHatch

nobody huh :<

AllMotorEFhatch

hmm, def some weird sh*t goin on there lol
, bump for you

sowellman88011

whens the last time that u changed ur fuel filter?

Sonia's Driver

There is no way this is happening without you getting at least one code. What's the ECU telling you? https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/how-pull-cel-d4-srs-abs-codes-code-lists-1901557/

I'm glad that you don't want to just throw parts at it.

OK, from your description, either no/insufficient fuel is being injected into the cylinders, it is being injected at the wrong time, the spark is weak or occurring at the wrong time, or you are losing compression somehow.

I would start with the fuel pressure and go from there. Rent a fuel pressure gauge from Autozone and measure the fuel pressure. It would be nice if the fuel pressure regulator had just failed so that the fuel pressure was all over the place.

Also, check the quality of the sparks: https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/diy-how-test-spark-troubleshoot-spark-problems-2919450/

Let us know what you find with those troubleshooting steps.

spoonhatchback2001

Here is where you should actually start. There is a realy under your dash. its got a 10mm nut and is located just above the brake and clutch pedal assuming it maybe a manual transmission car. This realy has a 10 pin plug its a small little box with a gray colored cover with some white writing on it and brown piece that the harness plugs into. This relay works in conjunction with you Ecu it basically control all you ingnition, spark, fuelpump. looks like this

Once you get it out and pop the gray cover and look at the circuit board for cracks on the some of the bigger sotter points. hers an image of what to look for.


You have two options from here. you can use a sottering iron and melt the points to the cracks arent there or you can purchase a new one. i say new because more than likely and used could be in the same condition. there about 50 dollars from the dealership. the sotter point become warm and crack like that so 99.9% of the time this is the culpret for hard or diffcult starts after driving your car or letting bake in the sun. hope this works

D16SiHatch

i haven't changed it at this point, only had the car running for less than a year now so i haven't had it very long. i suppose its possible it could be the culprit, just wanted to get some insight before i started throwin parts at it.

I find it hard to believe myself, but it is not throwing a code. The CEL does work, i can unplug the iacv for example and the light immediately comes on.

checking fuel pressure makes sense, however if it is low i imagine it would only be while its having an issue starting, since there is no problem whatsoever at any other time. It doesn't do it often enough or for a long enough period of time so it would be difficult to test it.

Yes i'm aware of the main fuel relay and how it functions, however what the car is doing is not indicative of it failing. If it cranked and did not attempt to start at all, and the CEL light and relay failed to audibly click on and off, then i would agree it was the relay at fault. If the relay can fail in the manner as i described above, it would be the first i've ever heard of such a thing.

spoonhatchback2001

Well i work at a local dealership and this is a very common culprit on 2000 and earlier model Hondas in general.