no start m20

[rede30]

I have had a rough e30 week. After realizing the m42 I was trying to start is out of time, I wanted to start a car. I needed to spend like 20 min to tighty up a friends car I am working on before I could fire it up. I got my truck up to jump the battery and it cranked and cranked but wouldn't fire. I drove this car 30 min less than a month ago and only did maintenance on it.

I did t-belt, valves, cooling system and some other odds and ends. Today I tested for fuel pressure to the rails and out the fpr and that checked out. I have spark to every plug, which are new and gapped right. I just triple checked my timing and tops line up. I have power to the fuel rail. And because I had my compression gauge sitting right next to me I checked comp even thought there is no way the car could run great and than have no comp after a few weeks.

since I have the components to make an m20 run, what am I missing? fuel timing and spark timing? My testing techniques could also be off.

[rede30]

I don't have intake leaks. And if I have a small one I am sure my car would still start.

[rede30]

Spend a few hours tinkering, still no go. Nothing makes sense in the world after this.

Could the spark some how be off. What if they all spark at the same time or something? Can that happen? could a distributer some how not distribute spark properly?

[riceh8r]

crank sensor maybe...

[rede30]

crank sensor maybe...

I always have that in mind but I have the understanding that I wouldn't get spark if that went. I could be wrong.

[redhatpat]

If the CPS is bad you wouldn't get any spark (the DME wouldn't know the engine is turning over).

Have you verified the injectors are firing?

[rede30]

Injectors have power and the spark plugs are wet when they are pulled. I keep asking myself if it is the problem though.

[jlevie]

If the engine has spark the next question would what pressure is in the fuel rail when the engine is being cranked over. If the fuel pressure is normal and the injectors are firing that leaves intake leaks or a mistimed cam. Since the timing belt has just been replaced, pull the covers and re-check am timing first. The check for intake leaks with a smoke test,

[rede30]

The timing was the first thing I checked. The rail has all sorts or pressure, I checked that.

[rede30]

Back to the spark question since I know I have all the components,can the spark time be off?

[jlevie]

The timing was the first thing I checked. The rail has all sorts or pressure, I checked that.

"all sorts of pressure" says nothing about whther the rail pressure is correct. A problem with the fuel system can result in insufficient or excessive pressure. Either of which can disable the engine. So the first thing to do is to actually measure the rail pressure with a gage. The next step, once the rail pressure is known to be correct, is to verify that the injectors are firing. That can be done by hearing the click from at least one Bank 1 and one Bank 2 injector, or using a noid light. And automotive stethoscope is the best way to listen for a click. but you can usualoly hear it by placing one end of a long screwdriver against an injector and placing your ear on the other end.

Back to the spark question since I know I have all the components,can the spark time be off?

Not unless the ignition wires are in the wrong order, assuming correct cam timing.