Changed can shaft in 88 Chevy now its not firing
Is it not firing as in no spark on the plugs, or is it not firing as in engine turning over and not starting?
An engine wont start for one of three reasons - one, no compression, two, no gas, three, no spark.
Start with no. three because it's the easiest to check. take off a plug wire, put something metal in there - phillips screwdriver, long nail, or if you're brave, you finger. Be careful, there should be anywhere from 20 000 to 30 000 volts in there, it won't kill you but it will make you say "darn" in a most unusual way. If there is no spark, there is your problem.
Secondly, check for fuel The easiest way is to spray a little Quick Start (ether) down the carb tube. If it fires now, that's your problem - no fuel.
Now for the worst part. Do you have compression? You worked on the cam shaft, so there is a likelihood you've got the timing wrong.
If you are unsure of the timing marks, you can check your valve timing (cam timing) on the valves.
Now this depends on what engine you have in the vehicle. Chevy made a bunch of models with a wide variety of engines.
You need to determine the opposing cylinders. On a six cylinder motor, that's easy. The firing order is 1-5-3-6-2-4, always (sorry, unless it is a V-6) On the straight six, the opposing cylinders are 1 and 6, 5 and 2, 3 and 4. What this means is that when cylinder no. 1 is up and has done its exhaust stroke, ready to go down for its intake stroke, its opposing cylinder (6) is at the top of its compression stroke, ready to fire for power.
What does all of this mean? If you look at the no 1 cylinder - always closest to the radiator, you need to turn the engine by hand until you see the valves "rocking", that is, the exhaust valve will move up at almost the same time as the intake valve is moving down. The opposing cylinder's valves will now both be closed.
Now, turn the engine until no. 6 is rocking, look at the front engine pulley and check that the timing mark is aligned with the mark on the block. If not, the valve timing is out and must be reset.
On a 4 cylinder, the timing could be either 1-3-2-4 or 1-3-4-2 or 1-4-2-3 Only VW and Porche boxer engines fire 1-4-3-2
Find out your fining order, the third cylinder will be the opposing cylinder to no. 1 and take it from there. V8's are a curse, but again, find out the firing order and the fifth cylinder will be the opposing one to no. 1. Good luck.
Oct 06, 2014 |
Cars & Trucks