91 2.5L New Engine Won't Run
borky58
07-07-2005, 12:56 PM
Newbie Here,
Need Help Bad
Read a lot of Threads and there are some pretty smart people here.
Hope you can help me!!!!!
I've always been told you can't give a mechanic to much information so here goes.
1991 S-10 Chevy Pick-up
2.5L Engine “E”
No A/C
I am the wife of an extremely frustrated husband who has been, and still is, trying his hardest to get this pickup running properly. It seems as though he is trying everything but nothing is helping. Spending a lot of money with no results.
I will try and explain the symptoms the best that I can, I hope that you will have patience with me.
This was his father’s pick-up before he gave it to my husband and he purchased it new. It was faithfully taken to the local dealer for the routine oil changes and maintenance. At the time that my husband received the pickup it ran fine at highway speeds but always seem to idle weird. It would rev up and then slow down. It wasn’t smooth. His father said that it had always ran that way.
He began to notice that there were small amounts of oil that were coming through the crankcase breather filter that affixes on to the air cleaner assembly. He was told to remove the filter and duct tape the opening in the air filter closed. Take a one gallon jug and set it somewhere under the hood. He should attach a longer length of hose to the 90 degree stub of hose that comes out of the top of the valve cover and run it into the one gallon jug. This would eliminate the oil build up in his air cleaner. So that is what he did. It ran for quite some time like that with no problems other than the ongoing rough idle issue.
About a month ago it started noticeably hesitating and jerking intermittently while driving at highway speed. If you accelerated it would help. It wasn’t all the time, it was intermittent. Then it started doing the same thing during in town driving at much lower speeds. At about 40 to 50 miles per hour was when it seemed to act up the most.
After explaining the problem to various mechanics he was told to replace the following so that is what he did.
We have replaced the spark plugs and wires, Distributor cap and rotor, throttle position sensor, ignition module, fuel pump relay switch, fuel injector and the oil pressure switch.
While driving to work one day it it became even more sluggish. Gradually losing power. After driving about 10 miles it had basically no power and threw out about 3 quarts of oil into that one gallon jug.
After that, it was towed to our home to do some investigating.
My father has been a mechanic for 40 years so he came and helped my husband tear the engine down.
The number two piston was greatly damaged.
So we ordered and have now installed a new long block. It still runs horribly
The timing was set at 8 TDC.
After a great deal of reading in the manuals that we are able to acquire, it states that the MAP sensor also regulates the timing, so we replaced that as well. It continues to run horribly. When it just sets and idles it runs ok for a short time and then it runs very rough and sounds like it is going to stall. If you give it the gas it sounds dead and very sluggish. The vacuum pressure is only 14 to 15 on idle. If you rotate the distributor while the engine is running the vacuum will come up and the engine runs much better and not as sluggish. But then the timing is far from 8 TDC as it should be.
Before any work was done we accessed the trouble codes by using a jumper. Believe it or not but no codes came up. It just continued to flash 12 repeatedly. Now, after all this work has been done, we tried accessing the codes again but with no success. The service engine soon light briefly lights up when you turn the ignition to run and then immediately goes off. We can not successfully access the codes as we have in the past.
The alternator died about six months ago so that has been replaced as well.
I am extremely sorry that this is such a long explanation but I thought the more in depth information that I could give you the better it would be to try and troubleshoot. You can’t begin to know how much we would appreciate any advice that any of you would be willing to share with us in order to get this pickup running.
If you need any more information I will gladly get it for you.
I Greatlly Thank You in Advance
Need Help Bad
Read a lot of Threads and there are some pretty smart people here.
Hope you can help me!!!!!
I've always been told you can't give a mechanic to much information so here goes.
1991 S-10 Chevy Pick-up
2.5L Engine “E”
No A/C
I am the wife of an extremely frustrated husband who has been, and still is, trying his hardest to get this pickup running properly. It seems as though he is trying everything but nothing is helping. Spending a lot of money with no results.
I will try and explain the symptoms the best that I can, I hope that you will have patience with me.
This was his father’s pick-up before he gave it to my husband and he purchased it new. It was faithfully taken to the local dealer for the routine oil changes and maintenance. At the time that my husband received the pickup it ran fine at highway speeds but always seem to idle weird. It would rev up and then slow down. It wasn’t smooth. His father said that it had always ran that way.
He began to notice that there were small amounts of oil that were coming through the crankcase breather filter that affixes on to the air cleaner assembly. He was told to remove the filter and duct tape the opening in the air filter closed. Take a one gallon jug and set it somewhere under the hood. He should attach a longer length of hose to the 90 degree stub of hose that comes out of the top of the valve cover and run it into the one gallon jug. This would eliminate the oil build up in his air cleaner. So that is what he did. It ran for quite some time like that with no problems other than the ongoing rough idle issue.
About a month ago it started noticeably hesitating and jerking intermittently while driving at highway speed. If you accelerated it would help. It wasn’t all the time, it was intermittent. Then it started doing the same thing during in town driving at much lower speeds. At about 40 to 50 miles per hour was when it seemed to act up the most.
After explaining the problem to various mechanics he was told to replace the following so that is what he did.
We have replaced the spark plugs and wires, Distributor cap and rotor, throttle position sensor, ignition module, fuel pump relay switch, fuel injector and the oil pressure switch.
While driving to work one day it it became even more sluggish. Gradually losing power. After driving about 10 miles it had basically no power and threw out about 3 quarts of oil into that one gallon jug.
After that, it was towed to our home to do some investigating.
My father has been a mechanic for 40 years so he came and helped my husband tear the engine down.
The number two piston was greatly damaged.
So we ordered and have now installed a new long block. It still runs horribly
The timing was set at 8 TDC.
After a great deal of reading in the manuals that we are able to acquire, it states that the MAP sensor also regulates the timing, so we replaced that as well. It continues to run horribly. When it just sets and idles it runs ok for a short time and then it runs very rough and sounds like it is going to stall. If you give it the gas it sounds dead and very sluggish. The vacuum pressure is only 14 to 15 on idle. If you rotate the distributor while the engine is running the vacuum will come up and the engine runs much better and not as sluggish. But then the timing is far from 8 TDC as it should be.
Before any work was done we accessed the trouble codes by using a jumper. Believe it or not but no codes came up. It just continued to flash 12 repeatedly. Now, after all this work has been done, we tried accessing the codes again but with no success. The service engine soon light briefly lights up when you turn the ignition to run and then immediately goes off. We can not successfully access the codes as we have in the past.
The alternator died about six months ago so that has been replaced as well.
I am extremely sorry that this is such a long explanation but I thought the more in depth information that I could give you the better it would be to try and troubleshoot. You can’t begin to know how much we would appreciate any advice that any of you would be willing to share with us in order to get this pickup running.
If you need any more information I will gladly get it for you.
I Greatlly Thank You in Advance
jackass#1
07-07-2005, 07:14 PM
might want to check the following:
fuel pressure (your manual should give specs)
egr valve(a very commomn trouble with the s10)
vacuum leaks
timming should be set 0 tdc
i have a 91 as well (but with a 4.3 tbi) my idle would surge like you described, drove like that for a good year and a half. never could figure out what it was, until the fuel pump went out one day. put a new one in and it totally solved the prblem. i needed 9 to 14 psi and when i had it tested early on i had somewhere between 8 and 10 psi. so i thought it was good, wrong.
hope this helps alittle.
fuel pressure (your manual should give specs)
egr valve(a very commomn trouble with the s10)
vacuum leaks
timming should be set 0 tdc
i have a 91 as well (but with a 4.3 tbi) my idle would surge like you described, drove like that for a good year and a half. never could figure out what it was, until the fuel pump went out one day. put a new one in and it totally solved the prblem. i needed 9 to 14 psi and when i had it tested early on i had somewhere between 8 and 10 psi. so i thought it was good, wrong.
hope this helps alittle.
OverBoardProject
07-07-2005, 11:23 PM
he's probably setting the timing wrong.
They have to disconect a wire for the proper reading.
BlazerLT explains it best on this link
http://www.automotiveforums.com/vbulletin/showthread.php?t=300204&highlight=set+timing
the botton comment
They have to disconect a wire for the proper reading.
BlazerLT explains it best on this link
http://www.automotiveforums.com/vbulletin/showthread.php?t=300204&highlight=set+timing
the botton comment
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