Engine and transmission problem

Tiny
REDHORSEM
  • MEMBER
  • 1999 CHEVROLET TRUCK
  • V8
  • 2WD
  • AUTOMATIC
  • 104,000 MILES
My problems started with the engine going full throttle at start up.. After I started it again it would surge between 2000 and 3000 rpm. I talked to a chev. Mechanic and he told me to hit the ecm. It dropped to an idle then ran like nothing happened. I replaced the ecm with a reman and followed the relearn procedure resulting in no start. The NAPA tech told me to reinstall my old ecm and it ran fine. ( Bad ecm ) I then drove the truck to a reputable mech. On the way it sped up to 85 mph while riding the brakes ! After a rough section of road it settlrd down and drove normally. The mech put the truck on his machines and could not get any codes except a one time low oil pressure. They could not get the truck to misbehave ! I told them to drive it on a rough road. That is when it did the same thing. They then called me to tell me that it was so bad the had to tow it in. Oh and by the way. Now the transmission is stuck in drive ! No matter where you place the shifter it is in drive ! Their diagnosis was a bad injector pump and replace the oil pressure sending unit and pigtail since it is oil soaked and been spliced more than once. No guarentee that wouild fix it and then deal with the transmission ! Could all of this be related since both the engine and trans are controlled by the ecm / Bad ground? HELP I don't want to spend another dime on this truck and am thinking of junking it !
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Sunday, January 16th, 2011 AT 4:13 AM

5 Replies

Tiny
HMAC300
  • EXPERT
Your cable to the trans may be bad causeing it to stay in drive. You can check it manually with teh engine off and a helper. Just crawl under it and see if the cable moves the lever on the side of the trans. If it doesn't it can be either an upper or lower cable, they are in two parts. Make ablsolutely sure that you have a ground cable going fromthe engine to body and that all grounds are clean, inclucding battery to engine ground. It still may be an injector pump. This really needs ot belooked at physically though.
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Sunday, January 16th, 2011 AT 4:34 PM
Tiny
REDHORSEM
  • MEMBER
It is not the cable. It was checked and moves the transmission into Park engaging the park pawl however the transmission is still in drive trying to move forward against the park pawl ! I am still checking the various grounds. The truck starts and runs fine when cold, when it warms up is when the engine goes haywire and the transmission worked fine when I drove it to the shop. Is the trans. Controlled electronically by the ecm? I know it is in drive because it shifts through the gears when driven.
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Monday, January 17th, 2011 AT 11:30 PM
Tiny
HMAC300
  • EXPERT
The transmission is controlled by the ecm. There are a bunch of electronic controlled shift valves as well as pressure regulators. It can also be a harness problem. But you hshold have had this scanned to see what the problem actually is. You need a pro model to get this and an auto parts store one only give you engine problem codes. You need to take this to a trans pro and let him scan it.
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Monday, January 17th, 2011 AT 11:35 PM
Tiny
REDHORSEM
  • MEMBER
I took it to a "reputable" shop for the engine problem. The transmission problem happened when they were test driving it to get it to mess up. They told me their scanner did not show any codes related to the trans or the engine problem ! I assume they have a professional scanner but, I am only guessing. Thank you for your help. I will try to find someone who has one and in the mean time I still may junk it !
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Tuesday, January 18th, 2011 AT 12:17 AM
Tiny
HMAC300
  • EXPERT
If you want to keep the truckyou can always put a junkyard trans in it. They are usually low mileage a rebuilt is anwhere form $12-1500 but have it checked by a trans shop not aregular mechanic. They are more familair with what goes wrong with them. You can tell him everything that you have done to it.
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Tuesday, January 18th, 2011 AT 1:10 AM

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