97 blazer 4.3w timing

iceman3032003 · 12-12-2011, 10:48 AM

Using a tech II scan tool it shows the timing is -11 but from what I can see is that the dist. has never been off. But also i do not know much history on the engine. Anyone have any thoughts on this when I bring number 1 up to compression it does look like it is off one tooth.

viggy58 · 12-13-2011, 05:58 PM

how many miles. is there any shaft play on the distributor?

is it having trouble running? throwing any codes?

iceman3032003 · 12-13-2011, 07:31 PM

it has 160,000 and i did pull the dist and the play is about average, it was not running good my son bought from a guy who said it just stopped running about a year ago after the guy tried a new fuel pump.
i have replaced all ecletronis emmisioon parts plus new rotor cap dist cap wires plugs coil ICM and also the cam sensor. we put new injectors on it and after that it would start but the idle was very fast almost 2000 rpm and still lots of black carbon from the tail pipe it also has a new cat. So i have thrown many parts at it with no improvement and yes the parts are ac delco or delphi from a dealer friend where I dod get them at his cost.
Now after re-installing the dist following the manuel procedure it will not even start now i am ready yo burn it. The only codes in the history are tps and ect both have been replaced

old_master · 12-15-2011, 08:35 PM

Timing should never go into negative degrees. Should read very close to 21 degrees at idle. Hook up your techII and check camshaft retard. Bring RPM to 2,000 and back to idle. Should be zero degrees plus or minus 2 degrees. If the distributor is off one tooth, or more, P1345 will set.

iceman3032003 · 12-15-2011, 09:33 PM

Thanks Old master that is some good advice, I did not know the crank balancer had two marks i found the one that brings up the compression. Put the rotor to the 6 mark on the dist and it started right up but is missing like it is still off on the timing. ishould have given me the 1345 code but did not. it will idle ruff for about 5 mins then the idle gets very slow and ruff then dies. i have always had v- 8's i still love my 1993 full size blazer damn thise things are so easy to work on this 4.3 is busting my B###s but what can you expect when you buy a pig in a poke like this one who knows what all has been done to it before it was not maintained very well. i am still getting the ect and tps high voltage code and now a 560 code low voltage but i have not to drive it to cycle the codes out let me know what you think about the missing and ruff idle it is not showing any mis fire codes. the plugs are ac delco new but they are black and the wires are new ac delco with new dist cap and rotor also ac delco with a new cam sesor also.

old_master · 12-16-2011, 01:59 PM

Yes, there are two marks on the damper. If you line them up like this, #1 is not necessarily on its compression stroke. What it does do, is put #1 cyl at TDC. It could be TDC of the compression stroke, or it could be TDC of the exhaust stroke, you still need to figure out which stroke #1 is on. Worst case scenario is rotate the crankshaft one revolution clockwise.

Your "5 minute" time frame could be when the PCM goes into closed loop operation causing the difference in performance. Figure out and fix the timing issue first: We know there's a problem there and it might be the whole problem. If it still doesn't smooth out, check fuel pressure and leakdown.

iceman3032003 · 12-16-2011, 02:07 PM

yes getting ready to go work on it more today the fuel pump pressure is good new fuel pump and complete spider injecters also. if ican can keep it running long enought i am going to test each cyclinder the new spark plugs could be fouled since they are all so black with running so rich. Thanks again for you help

old_master · 12-16-2011, 09:22 PM

Something else to check.... after the engine sets overnight, (at least 8 hours), before starting the engine, connect the techII & compare ECT & IAT temps, they should be within ~2 degrees of each other. Might want to make sure the cap is wired correctly too:

Post your results.

iceman3032003 · 12-17-2011, 04:29 PM

I double checked the timing marks and that number 1 is up on compresion set in the dist. to the number 6 mark on the dist housing. made sure wires were correct per the firing order and the numbers on the dist. cap. the ect and iat were both -40 prior to starting the engine, when it starts it will not idle i need to rev it up to around 2000 rpm and it misses like the firing order is wrong I rechecked the wires and the timiming marks to the rotor button marks and the dist. marks all line up. This is my son in laws tech II I am not to knowledgeable about it but when it is running I looked at the mis fire graph and it shows no mis fire. One thing it is not doing now is the amount of black smoke from the tail pipe it is more white now. it is not showing the 1345 code but it is showing the 1100 codes for the tp and still also the code for the ect they will not clear. any more thoughts your help has been great so far thanks

rhandwor · 12-17-2011, 04:54 PM

Quote:

Originally Posted by iceman3032003

I double checked the timing marks and that number 1 is up on compresion set in the dist. to the number 6 mark on the dist housing. made sure wires were correct per the firing order and the numbers on the dist. cap. the ect and iat were both -40 prior to starting the engine, when it starts it will not idle i need to rev it up to around 2000 rpm and it misses like the firing order is wrong I rechecked the wires and the timiming marks to the rotor button marks and the dist. marks all line up. This is my son in laws tech II I am not to knowledgeable about it but when it is running I looked at the mis fire graph and it shows no mis fire. One thing it is not doing now is the amount of black smoke from the tail pipe it is more white now. it is not showing the 1345 code but it is showing the 1100 codes for the tp and still also the code for the ect they will not clear. any more thoughts your help has been great so far thanks

Did you double check the wiring for the injectors when you worked on them?

old_master · 12-17-2011, 04:59 PM

If ECT and IAT were both showing -40, there's a problem. I don't think the temperature in Ohio got quite that cold last night

-40 is a default reading.
Check fuse #9, 20 amp fuse, should show battery voltage at all times.
Check fuses #4, #5, #10, #12, & #15 all should show battery voltage with the ignition in RUN and START positions.

Check both terminals of each fuse with a voltmeter or test light & post your results

iceman3032003 · 12-17-2011, 05:33 PM

I will check the temps again on the ect and iat to be dure they are right with what i said. # 9 was 12.54 4 -11.44 5 - 11.49 10 - 10.54 12 - 11.44 i could not get a reading from #15

old_master · 12-17-2011, 07:45 PM

Fuse #15: You can check the pink wire at the mass air flow sensor with the ignition in the RUN position. Let us know what you find on the recheck of ECT and IAT.

iceman3032003 · 12-17-2011, 09:15 PM

I re-checked #15 and it was reading 8.97 the battery was reading low also so i put a charge on it for the night. I looked at the ECT it is now showing 86 at start up but the IAT is still showing -40

iceman3032003 · 12-17-2011, 09:51 PM

Something i am not sure if I said before but i am also getting a code 560 system voltage but i cannot find any reference to it any place

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