1993 Suburban Crankshaft Position Sensor Problem?

ritter875 · #1 02-21-2009, 02:35 PM

A few months ago I was driving to work when my '93 Suburban just shut off. Plenty of gas, brand new fuel pump....it just quit. I tried restarting it. That didn't work. Then 5 minutes later I cranked it over and it fired right up. I drove probably another 10 miles when it happened again. Through researching online I've found that this could be the crankshaft position sensor, but when I go to buy one, no one has them listed for a '93 Suburban. The problem is still the same. It's sitting in my driveway and will be for some time if I can't get this one figured out. My mechanic thought I was crazy.

If anyone can help, it would be much appreciated.

Thanks,
John

777stickman · #2 02-21-2009, 05:34 PM

Welcome to AF. What engine??? I'm pretty sure the reason you can't get a CKP for your '93 is because they started in '96 with the OBDll system. Not sure where you did your research to come up with that, but there are many other things to consider for your problem.

When it dies what's the fuel press? Does it have spark at the plugs? Is the CEL on? Etc, etc, etc.

PS: What was the reason for your mechanic to think you're crazy??

ritter875 · #3 02-21-2009, 06:58 PM

I was researching it online. You are right about the crankshaft position sensor. The '93s don't have them. I just talked to a guy from advanced auto today. He was actually very helpful. Said it was probably the ignition module/control unit. I tore mine out and ran down there, replaced it and now it runs fine. No more stalling for no reason. On my test run though the check gauges light came on and now I have no oil pressure. There's always something. I drove on it for about 2 miles before finally pulling over and parking it. I can only hope I didn't trash my entire engine block. I didn't notice any oil leaks, so I figure it must be the pump, but I don't know. Any ideas?

ritter875 · #4 02-21-2009, 06:59 PM

It's a 5.7 liter, gas.

j cAT · #5 02-21-2009, 08:24 PM

Quote:

Originally Posted by ritter875

It's a 5.7 liter, gas.

when you made this repair did you remove the distributor.?

ritter875 · #6 02-21-2009, 08:53 PM

Yupp, on mine there are only two bolts to remove and the distributor cap pops right off, the problem is getting to the two bolts within the housing that hold the ignition module on. I just labeled all my plug wires and the nipples they corresponded to and got the distributor cap housing out of the way. That gave me room to work. The connector on the back side of the ignition module would be almost impossible to get to without removing the distributor cap.

ritter875 · #7 02-22-2009, 08:58 AM

Yupp, on mine there are only two bolts to remove and the distributor cap pops right off, the problem is getting to the two bolts within the housing that hold the ignition module on. I just labeled all my plug wires and the nipples they corresponded to and got the distributor cap housing out of the way. That gave me room to work. The connector on the back side of the ignition module would be almost impossible to get to without removing the distributor cap.

My mechanic thought I was crazy because he couldn't get it to stall. He told me to come pick it up and claimed there was nothing wrong with it. It stalled again on the way home from there.

j cAT · #8 02-22-2009, 10:37 AM

Quote:

Originally Posted by ritter875

Yupp, on mine there are only two bolts to remove and the distributor cap pops right off, the problem is getting to the two bolts within the housing that hold the ignition module on. I just labeled all my plug wires and the nipples they corresponded to and got the distributor cap housing out of the way. That gave me room to work. The connector on the back side of the ignition module would be almost impossible to get to without removing the distributor cap.

My mechanic thought I was crazy because he couldn't get it to stall. He told me to come pick it up and claimed there was nothing wrong with it. It stalled again on the way home from there.

the oil pressure problem may be the sender connector got moved or your distributor removal somehow damaged the oil pump ...

if you have no pressure the engine would make noise...recheck the wiring around the distributor area/oil sender...then if necessary put gauge on to verifiy the oil problem..

the ignition modules usually go around 150,ooo-225,ooomi,,,unless the plug wires/cap/rotor are defective and you had a lot of arcing..

ritter875 · #9 02-22-2009, 11:54 AM

Quote:

Originally Posted by j cAT

the oil pressure problem may be the sender connector got moved or your distributor removal somehow damaged the oil pump ...

if you have no pressure the engine would make noise...recheck the wiring around the distributor area/oil sender...then if necessary put gauge on to verifiy the oil problem..

the ignition modules usually go around 150,ooo-225,ooomi,,,unless the plug wires/cap/rotor are defective and you had a lot of arcing..

As of right now it has 235,000 miles on it, so you got that right. The ignition module was due to go. The test at Advance Auto confirmed that was the problem. I don't think I damaged anything in the process of removing the distributor cap, but I I'll definitely double check.

I went back to it this morning and started it up praying it wouldn't be knocking like hell, and it actually wasn't. The oil cooled and became thicker overnight apparently, but my oil pressure gradually dropped as I got closer to home. It's sitting in my driveway again without incident. Dipstick says there is plenty of oil.

I will look into what you mentioned. Someone told me the oil pump is located inside the oil pan. I find that hard to believe, because it would be such a pain to work on. Do you know if the rumor is true?

j cAT · #10 02-23-2009, 12:21 PM

my question was did you remove the DISTRIBUTOR......? NOT the cap...of the distributor....

the oil may be have fuel in it causing the oil to be of a very low viscosity..and yes the oil pump is in the oil pan....like the sump pump would be in your basement not the attic...

ritter875 · #11 02-23-2009, 01:39 PM

Quote:

Originally Posted by j cAT

my question was did you remove the DISTRIBUTOR......? NOT the cap...of the distributor....

the oil may be have fuel in it causing the oil to be of a very low viscosity..and yes the oil pump is in the oil pan....like the sump pump would be in your basement not the attic...

No I did not remove the distributor. What reason would I have to when the ignition module sits right under the distributor cap? I am no mechanic, but I believe if you want something done right you have to do it for yourself. I'm looking to save some money on labor costs as well.

I posted this looking for a few pointers from some people that know more than I do. One problem down, one to go, so I do apologize for not knowing where the oil pump was for sure. Now I know.

I didn't smell any gas in the oil. Someone told me it could be a worn out crankshaft bearing causing an interior leak or something along those lines, but I honestly don't know. A repair like that is above and beyond me.

777stickman · #12 02-23-2009, 08:04 PM

From reading the posts, it sounds like this oil press problem started after the dist work. If that's true then you need to look more closely at the sending unit connection which should be right behind the dist and a little to the drivers side.

When j cAT asked if you had removed the dist your reply was "YUPP...........".

The reason for his question is that the cam drives the dist and the dist drives the oil pump, which is indeed in the oil pan sump.

j cAT · #13 02-23-2009, 08:19 PM

Quote:

Originally Posted by ritter875

No I did not remove the distributor. What reason would I have to when the ignition module sits right under the distributor cap? I am no mechanic, but I believe if you want something done right you have to do it for yourself. I'm looking to save some money on labor costs as well.

I posted this looking for a few pointers from some people that know more than I do. One problem down, one to go, so I do apologize for not knowing where the oil pump was for sure. Now I know.

I didn't smell any gas in the oil. Someone told me it could be a worn out crankshaft bearing causing an interior leak or something along those lines, but I honestly don't know. A repair like that is above and beyond me.

you see I have no idea your knowledge level...removal of the distributor is done by some to repair this module, and also to inspect for other issues with it..

with the spark being bad I would change oil and see if the pressure returns....worn bearings take a long time to wear out so as to cause a oil pressure drop....you had this suddenly occur after the bad spark ...

ritter875 · #14 02-24-2009, 05:53 PM

Quote:

Originally Posted by j cAT

you see I have no idea your knowledge level...removal of the distributor is done by some to repair this module, and also to inspect for other issues with it..

with the spark being bad I would change oil and see if the pressure returns....worn bearings take a long time to wear out so as to cause a oil pressure drop....you had this suddenly occur after the bad spark ...

I'm back out at Penn State now, so I can't work on it for a while. I'm sorry for the confusion with the distributor question. I'll check it out when I make it back home again. My old man works on the road this time of year, but when he's home I'll be sure to make a trip so we can work on it.

The only thing I don't understand, is I had driven roughly 10 miles or so before I had a problem with oil pressure, so the engine had to have fired thousands of times without any problems, then all of a sudden I looked down and the check gauges light was on and I had no oil pressure whatsoever. I appreciate your time. You have been very helpful so far. That ignition module had us stumped.

Thanks,
John

ritter875 · #15 03-13-2009, 10:36 PM

We changed the oil. Oil pressure returned and has been running strong since. Appreciate the help.

John

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