F20Cdriver

[QUOTE=RED MX5,Feb 11 2008, 12:28 PM]How was the car running during the 651 miles you drove it?

F20Cdriver

yah he knows, he suggested i get an ecu the first time he put my engine together.

F20Cdriver

no, the knock sensor was jacked up by the first shop i had install my engine.

RED MX5

Like everyone else who has commented, I'm a little surprised that the car ran at all (at least without throwing a CEL) with the lowered compression, but obviously it did. Do you have any idea what the A/F looked like? It seems to me that if the car had been excessively rich, or excessively lean, the ECU should have thrown a CEL, and since it didn't, I *guess* it must not have detected anything too far out of spec. Since the car ran OK before, I too suspect that something in the wiring, or elsewhere, got buggered up during the engine install, but it sounds like you are now getting a major misfire due to lack of spark, fuel, or compression. Have you run a compression check yet?

F20Cdriver

no compression check yet. by the way, what exactly is the purpose of a compression check?

RED MX5

A compression check will tell you whether or not the valves and rings are sealing.
If you don't have compression, the cylinder won't fire. Could be the cause of your misfire.

Do both a wet and dry compression check. While you're at it, you might want to do a leak-down test, but I don't think it will tell you much at this point.

If you pull the coil packs one at a time, you might be able to figure out which cylinders are missing (or if it's a random misfire in all cylinders). When you pull the coil pack of a cylinder that is firing, the engine will run worse, but when you pull the coil pack of a cylinder that is not firing, the engine will run the same as before (no better, no worse).

If you are getting spark and compression at all four cylinders, then I'd check for fuel flow. If you have never worked with fuel injection before, you might want to have someone else do this for you, as the high pressure in the fuel lines has to be released to avoid spraying fuel all over the place. If you follow the instructions in the Honda factory shop manual, you'll be fine.

FWIW, this is not a problem I'd want to try to trouble shoot on my own. I'd check for spark and compression, and if I didn't find the problem, I'd probably get our truck out here and take my car down to our shop so our chief mechanic could sort it out. It's not that I couldn't troubleshoot the problem, but just that it's apt to be a time consuming PITA if it's not something obvious. If you're unsure about the purpose of a compression check, you might want to defer all the troubleshooting to someone else.

RED MX5

BTW, you may have trouble finding a Honda dealer that will be willing to work on your modified car.

F20Cdriver

yah, i've been turned away from my local dealer already. i'll have to try those tests tomorrow and see what happens.

thanks for the help buddy!

RED MX5

I don't know how much help any of this will turn out to be, but at least it's a start.

Good luck!

F20Cdriver

well i reset my ecu and wallah, the engine idles perfect after following all of the procedures on the shop manual. my check engine light is still on, but i think the random misfire code is gone now. I'll find out tomorrow morning when i get to auto zone and plug in the engine code scanner. at least I'm getting somewhere with this trouble shooting process. it's frustrating when nothing happens after awhile. oh yah, i think I'm gonna have to pull the motor. I'm hearing noise from the timing chain during start up and acceleration.