weird acting engine *problem still, no help yet*

[BigOrange90Jimmy]

The TBI 350 in my 90 Jimmy is running kinda awkward. After I had it tuned up, it started running rough. When just plain riding around, it's fine. When I start it in the morning, or any time that the engine is cold, it runs like a 3-legged dog. It skips and is just plain rough, but if you rev it up one time, it runs fine. Also, when it's hot and when you're barely on the throttle, it starts sounding like it's got a big cam in it, kinda like it's loading up the cylinders before it fires. What is you take on this?

 

[87sm465np208]

Re: weird acting engine

my 87' 350 tbi 149600 miles, its starting to not want to idle high in the morning when i turn it on anymore, and it will acctually stumble and die, and then i turn it on again, and hold it at about 1000, and then drive it around for a bit, it runs fine, i dont know, im as clueless as you /forums/images/icons/confused.gif

 

[lizard]

Re: weird acting engine

well you should check to see if the computer has any error codes set. also look at the IAC - prolly gots lots of carbon

 

[bryguy00b]

Re: weird acting engine

my dads 79 runs like that...but thats of course carburated so its proboly totaly different..

 

[87sm465np208]

Re: weird acting engine

how do i get to the IAC valve?, and what do i use to clean it?

 

[87sm465np208]

Re: weird acting engine

this is pissing me off

 

[ntaj*ep]

Re: weird acting engine

See if the water temp. sending unit is connected to the computer, or which sender goes to the computer. There maybe one for your gauge and one for the computer, or they maybe one in the same. Get a new one and reset the computer, either disconnect the batt. or the fuse for clearing codes. After that it will run fine when cold. /forums/images/icons/grin.gif If you have any other questions feel free to PM me. /forums/images/icons/grin.gif We can fix it together!!

 

[BigOrange90Jimmy]

Re: weird acting engine

what? how the hell do i do that? i'm all thumbs when it comes to electronics

 

[BigOrange90Jimmy]

Re: weird acting engine

i ask the question for me and somehow we're now talking about someone else's problems /forums/images/icons/mad.gif what gives?!

 

[BigOrange90Jimmy]

Re: weird acting engine

how do i check for error codes. and i'm not paying the $45 an hour labor charge at the dealership

 

[BigOrange90Jimmy]

Re: weird acting engine

ttt

 

[ntaj*ep]

Re: weird acting engine

Just go get a Haynes or Chiltons manual at the local parts store and it will tell you how to read/clear the codes. Go to the Dealer and ask them for the water temp sender for the ECU. Ask them where on your engine it goes and they will tell you. If you don't want to pay them get the part # from them and go get it somewhere else. The # will cross referance to other brands. The books will break it down for you, and you have this board as well. /forums/images/icons/grin.gif You can figure it out and have it running in no time. /forums/images/icons/grin.gif

 

[BigOrange90Jimmy]

Re: weird acting engine

so that's all that's making my engine run like crap? just a water temp. sending unit?

 

[moneypit]

Re: weird acting engine

Got similar issues. Gettin pissed too. I am leaning towards a wire grounding.If the temp sender fixes your issue please let me know.TIA /forums/images/icons/smile.gif

 

[BigOrange90Jimmy]

Re: weird acting engine

is your's "fool" injected too?

 

[jeffro]

BigO',
You need an EGR valve. That's what it sounds like to me. I've had to replace a couple on my wife's 93 GMC TBI.

 

[BigOrange90Jimmy]

thanks man. those are cheap and i actually know where they go /forums/images/icons/tongue.gif

 

[MontanaLifted]

Best bet when it comes to computers is check the codes. You gotta get a code reader and figure out how to "talk" to your engine. It will tell you what it needs.
-Or you can chase your tail and replace every sensor until the problem goes away. After it's all said and done a cheap code reader would have been less expensive.

 

[ntaj*ep]

OK, I am not a fan of "mine did this so it must be wrong with yours" I'm not flaming anyone, you just can't fix your rig like that. It will just cause more frustration, and cost you more money.
You do need to read and decifer the code your truck is throwing at you. If you don't know/are unwilling to do it then you need to find someone that will do it or show you how to. After you find the code, you need to spend some time thinking about why it coded. I'll give you an example of this (a very common example at that)
***example has nothing to do with anything***You read codes, o2 sensor failure. You clear the code and drive the truck, it recodes, you find o2 failure again. OK we have an issue. You test the o2 sensor (reson why most people go to shop) it is testing faulty, why? Is the sensor bad? Or is there something else on the engine making it run rich or lean? HHHHMMMMMMMM /forums/images/icons/confused.gif***example has nothing to do with anything OVER***
Now I will give more examples, there are about a dozen diffrent sensors that can make you engine run rough, hard start. Are you going to replace all of them?
I say your water temp. sender for the ECU is faulty because you said it runs crappy, and is hard to start. The temp sender tells the ECU what temp. the motor is at. If faulty the rig will run rich, throw out a code (possibly o2, but who knows) and run like sh!t. /forums/images/icons/tongue.gif A stuck EGR valve would do the same, however it would not get better when warm, it would smooth out at cruise though. As my answer is speculation so is this. /forums/images/icons/laugh.gif Read the code. /forums/images/icons/grin.gif

 

[BigOrange90Jimmy]

good job on that post man. that's the best example I've read lately. i haven't started doing anything yet. i'm in Boone right now, so it'll probably be a while before i get to it. i guess i'll take it back to the guy who tuned it up. maybe he can tell me something.