Wont Start but have spark and fuel

xupkid2 · 02-16-2008, 09:10 PM

So I just put in a new motor and I can't get the car to fire up. I have already tested that there is spark and there is. I have checked the fuel and injectors and that works fine. I tried a new DME and that didn't work. I checked to make sure the speed and reference sensors were in good condition and they are. I believe the sensors are adjusted correctly. I am now at a loss. The DME relay is fine and the car does not have an alarm module. To me this has to be a timing issue. I checked the distributor and cap and those are fine. Any ideas on what it could be??

legoland951 · 09:31 PM

If you have properly timed spark (correct firing order) and fuel shooting out of injectors properly, then the only thing is your compression (bad rings/piston/valve) or wrong cam timing (bent valves). Check your compresssion.

BTW, how did you check the functionality of the injectors?

Razorback1980 · Razorback1980's Garage

Check the rotor to make sure it is where it's suppose to be. Can you rotate it without turning the camshaft? If you have spark and fuel then the only thing left (providing your compression is ok) is timing. The computer adjusts the timing along with the proper belt alignment. Did you do a compression test to make sure the numbers are what they are suppose to be?

jmd_forest · 02-17-2008, 07:10 AM

As mentioned by others above, double check your timing and compression first. OK...you say you checked and have spark, but did you check each spark plug individually to ensure you have spark at each plug? Are the plug wires installed in the correct firing order? If not, it' a common mistake, don't feel bad. You say you checked injectors, but are the injectors actually passing fuel? Checking with a noid light only ensures the electrical injector pulses are arriving at the injector, not that the injector is actually working. Did you check fuel pressure or just presence of fuel in the fuel rail. If the fuel pressure regulator is dumping all the fuel back to the gas tank, you'll never get the pressure needed to pass fuel through the injectors.

Try a squirt of starting fluid in the intake. If it fires up, most likely a fuel problem, if not, electrical or mechanical. At least it will start to narrow down the variables.

jmd_forest

xupkid2 · 02-17-2008, 06:38 PM

Well the compression test was the key. I found I had no compression in cylinder #3. After pulling off the intake I found a bent valve and now that I have replaced it the car is up and running.

Thanks for the help

legoland951 · 02-17-2008, 11:36 PM

No compression in one cyclinder will not cause the engine not to run. I guess the timing belt was off enough teeth causing the bent valve, wrong timing, and no compression. Anyways, great to hear you got the car up and running.

xupkid2 · 02-18-2008, 06:02 AM

Unfortunately the bent valve was the only cause for the engine not running. The timing was correct as I bent the valve while assembling the motor setting up the timing. After I put the cam tower on I did not have everything set to TDC so I had to rotate the engine and that caused the valve to bend.

While pulling the head to change the valve I double checked the timing and it was all set correctly. I didn't think a bent valve could cause the motor not to start either but once I changed the valve and assembled it again she started right up with no issues.