Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Hi Im David, the first thing i would do is a compression test. Thats mandatory in my shop as a first step before replacing anything.
ok, not bad. have you the wires yet? you may want to. or just swap wires to other non misfiring cylinders, see if it follows
other than the misfires are there any other codes?
excess fuel entering the combustion chamber can be causing this. i think that the fuel pressure is a bit high, but i would have to check that spec. another thing would be leaky/clogged injectors. do you have a noid light?
that damn spider....... what a design
ok. Im not sure that you did all of this yet, clean out the throttlebody, iac and egr. and the passages for them. also a backpressure test on the cats wouldnt be a bad idea.
also clean the maf while you are at it.
ok. good we have something to go by now...let me do some digging........
it has to be a tooth off. or its 180 off. even though you believe the timing is correct, its possible to set it 180 out. pull #1 plug come up to tdc on compression stroke., pull distributor rotate oil pump shaft and reinstall distributor as per normal timing procedures. ill be back in a bit
ok my friend. let me figure out our next step then
is that a 4.2?
im meant 4.3, and i know it is, dont know why i asked
ok, I believe now that since the timing is checked and double checked, distributor replaced, plugs replaced, AND you are getting random misfires and the sensor correlation code. the culprit will be the crankshaft position sensor or the wiring to it. have you put a timing light to it?
are you able to clear the code? and then start it again see if that particular code comes back?
if that that code comes up, it has got be be off a tooth. pull the distributor up and rotate it one direction or the other. when the distributor was replaced it came with a new cam sensor?
have you checked the wiring from the crankshaft position sensor up? also what about the reluctor whhel that the cranshaft sensor picks up its signal? clean? not bent? not damaged?
wow. have you cleaned out the egr valve?
gimme a sec...thanks
See if this procedure is exactly what you did.Timing is not adjustable per-say by turning the distributor, as that function is handled by info supplied to the ECM by the crankshaft sensor and the camshaft sensor. To re-set the distributor, bring #1 cylinder up on compression, align the timing marks on the damper pulley and put the distributor in with the rotor pointing towards the number “6” inside the cap.There are actually two timing marks on the damper pulley . When you are timing the engine, make sure to use the latter timing mark. If you use the other, engine won't start. First mark is before TDC and the second one is TDC. When you rotate engine, don't use the first mark but the second. At TDC the other mark is pointing at 3 o'clock, not 12 o'clock. You can try both of those it doesn't harm the engine.When you get it the engine TDC compression stroke point the dist rotor as shown in this picture.http://files.automotiveforums.com/gallery/showphoto.php?photo=51302If you try to point it to #1 plug wire where it comes out of the cap it does not work. Crazy caps crossover every which way before the fire goes out of the top.After you get it running you will need to set the camshaft retard setting with a scanner. You will need a engine data scanner capable of reading the camshaft offset degrees.It will read them in - or + degrees. You need to get it at least 2 degrees -or + or a close to 0 - or +degrees as you can. If it is over 3-5 degrees off the PCM/VCM may set a code on it. What it does is center the dist rotor dead on with the spark wire terminal. You will have to turn the dist to adjust it while watching the setting on the scanner. It has nothing to do with dist timing which is controlled by crank sensor. i dont know if your scan toll reads offset degrees or percentage.
if there was any discrepancy from the way you did it, let me know. if not we will push on
ok. im going to opt out and let another tech jump in here. im out of ideas. good luck to you.
i my name is ***** ***** will see what i can do to help in the endeavor of yours. can you provide me with a picture of you distributor cap with the wires going to the plugs mainly just the drivers side since this is the side you are having issues with?
also when you did the compression test did you have all the plugs out on the bank or just the cylinder you were test?