Hi,
I have a 1995 Del Sol Si that cranks fine and sounds fine but rarely fires and never enough to start. It ran fine before it stopped running while driving. Here is what I have done. Initial spark check led me to believe I may have bad cables. Replace all cables and plugs but no change. Checked the spark again while cranking and all 4 spark. Checked fuel pressure with key in on and got 38psi. Check compression, 150, 60,120 and 120. One pretty bad and two a bit low but it does not seem to be enough to not start. Read the codes (counted engine light flashing and got 6 (water temp), 10 (air intake temp and 21 (spool solenoid). Both temp senors read about 2K ohms bot into the senor and into the ECU (with the connector removed). Not sure what to do next. Distributor was replaced about 2 years ago. Timing belt replace at 113K miles. Now has 155K. Thanks for any suggestions.

 

Test another ECU in your car or your ECU in another car.

 

Thank, I'll see if I can track one down. Is it possible the low compression is the problem or should it still start?

 

I understand it should still start...

 

Those compression numbers are really low... the engine may NOT start with those numbers. It may "try" to start and hit one cylinder every now and then, but it is unlikely that it will actually catch and run on it's own... you will have to pedal the gas to keep it running if it does miraculously start.

 

What you describe is exactly what it does. What's the next step? Check the head gaskets? Are there any good links to describe what to do next? Thanks!

 

Pick the lowest compression cylinder, move that piston to the valve adjustment position by rotating the crank pulley until the cam gear is in the appropriate orientation. Remove the schrader valve from your compression tester and install the hose in the spark plug hole. While placing the transmission in gear and pushing the brake pedal to the floor, connect compressed air to the compression tester hose. Now listen to where the air is leaking out... if it is either through the throttle body or out the exhaust, then you have either bad valve sealing or a blown head gasket. If it comes out of the valve cover or dipstick, you have piston/ring/cylinder wall damage and the bottom end will need to be rebuilt.

 

After 2 years of taking up garage space, I am back to the del Sol project.Before the hiatus, i adjusted all the valves. They did need some adjustment, although it was not much. It still did not start. Yesterday, I decided to start over. I checked compression first. All cylinders matched pretty close. 1st rotation gave me 60, 2nd was 90 and then slowly increased to about 135-140 after 7 or so cycles, I did this with the distributor connectors off, the main relay out (for fuel pump), the throttle at full and all plugs out. Then I connected the distributor and relay and installed all but one plug. I connected the 1st plug to the cable, grounded the plug body and cranked and saw good spark. I repeated with the 2nd and the spark was good and the engine tried to fire even with just three plugs in. I put all the plugs in and it started up and sounded pretty good. Repeated a few times and then drove it up and down the driveway. Under load at idle it was pretty rough and would sometimes stall. At 10+ mph it ran fine. Next day i was going to check for a vacuum leak but it again did not start. I repeated the compression and spark tests (all 4 this time) and the compression was the same as yesterday and the sparks good. My next step is to check the fuel pressure. Any other thoughts? Thanks.