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'98 GMC Sierra with engine problems

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  #11  
Old 03-23-2007, 01:03 AM
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Default RE: '98 GMC Sierra with engine problems

Argon , heres whats happened so far- last Saturday we did only the injector change on #6 . It idled a littlerough still (but better)and the light didn't come on - until Tuesday night when it did. Now it barely wants to idle like at a stop light . I throw it into neutral until the light changes. I'm suspecting the intake gasket again (no , we didn't get that far into the work ) which I plan on getting into this weekend since its supposed to rain and I really have nothing to do . At work are guys who do a lot of motor work on their own and one in particular has built a few race engines for a local dirt track racer. He thinks I may have a leaking valve seal (umbrella seal??) on that cylinder . He's still wondering why #6 is the problem and not 8 or 7 if it is. Right now ,I'm pretty strapped for cash because of other expenses we had to make recently All but one of our appliances took a dump within a 3 month stretch,plus a $1K furnace fix we weren't exactly prepared for either. I need to figure this out . I might be able to swing getting the heads worked . Only problem is , if one is cracked or more than a typical head job ,I'm screwed. Still its better than a new car payment. I'm even considering a crate motor from Jegs(2 yr warranty) and paying on time with it. At least I have a motorcycle to ride while its down.
 
  #12  
Old 03-23-2007, 07:27 AM
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Default RE: '98 GMC Sierra with engine problems

Any new codes?...Maybe a gas leak under there?..or a vacuum leak at that stupid oval gasket??
 
  #13  
Old 03-23-2007, 07:57 PM
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Default RE: '98 GMC Sierra with engine problems

Don't know that yet - will get the scanner this evening before I tear into it just for S&G's.
I ran into a guy at work today (the vending machine guy) somehow we got on the subject and he has a '97 Monte Carlo that had the same exact problems my truck has - it was his intake gaskets . Only he had the problem on #1 cylinder . Sucking oil from the lifter galley and fouling the plug. Also a little coolant leaking.
 
  #14  
Old 03-24-2007, 05:48 PM
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Default RE: '98 GMC Sierra with engine problems

Argon, my friend didn't have his scanner so I wasn't able to get the code - BUT, I did the intake gaskets last night (6 pm til around 1 am)then slept on it before I fired it up this morning. Notice- the gasket area feeding 6/8 was distorted ,almost looked like the gasket warped down towards the downside of the head. The edge of the gasket was just about off the edge of the mating surfaces. #2 didn't look to good either .The design of these manifolds and their gaskets are junk .2 bolts on each corner about 3 inches apart over the coolant ports and a wide open area between and over the intake ports. Anyway - I got it fired up after a fresh oil change .No leaks !!! Blew all kinds of crap out the tail pipe. Obviously what fell into the ports on the dismantle . Had a long dispute between me and the coolant system though- it had a major air bubble that wouldn'tallow passage to the heater core and the temp was showing hot but blowing cold air - I kept having to burp the quick disconnect at the manifod tothe heaterhose .Once that issue was over - Itstill runs like crap. An obvious miss. The SES light is on . I pulled the spark plug to #6 that was fouling before.The good news is its not fouling anymore . But the exhaust smell is like a new truck / new cat converter-egg smell.
I called my buddy that works in a GM shop the one that helped me change the injector . He and I are still racking our brains as to the problem -dirty injectors??? We know it has good spark.This coming Monday is supposed to be decent riding weather so I guess I will bite the bullet and have my wife take it up town to the dealer shop and see what they think.
 
  #15  
Old 03-24-2007, 10:18 PM
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Default RE: '98 GMC Sierra with engine problems

Could it be wired wrong?...If it has such a bad egg smell..it must be missing pretty bad (not just a vacuum leak)....If its wired correctly,could an injector be in the wrong slot?

Or could the timing be off?...its very easy to get those things a tooth off.

Hang in there,bro!
 
  #16  
Old 03-26-2007, 07:49 PM
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Default RE: '98 GMC Sierra with engine problems

As far as I know - no , its not wired wrong .When I put the dist back on ,I put the wires back where they came from .Its still 1-8-4-3-6-5-7-2, right? Plus whatever the cap says on each terminal (in case it isn't).I mean , I'll go check , but I doubt its wrong. It starts and runs (kind of) it just has the bad miss still. still no leaks -it sat since Saturday when I gave up on it. My wife called the garage in town (less than 1 mile away) ,I should be getting it in tomorrow . I just hope its something dumb I overlooked. I remember writing down the numbers on the injector pack as to where they went and I made a "map" when we hooked them back up .
 
  #17  
Old 03-26-2007, 09:31 PM
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Default RE: '98 GMC Sierra with engine problems

plug wires are on right- traced each one from the dist back down to each plug.
I also did something I haven't done since I bought the truck - I read the manual. Supposedly the SES light if a misfire should be flashing (but its not) now in the case it is not flashing it says it should be a emissions problem . I guess I'll find out tomorrow .
 
  #18  
Old 03-26-2007, 10:30 PM
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Default RE: '98 GMC Sierra with engine problems

Yeah,it will flash if its a "converter-threatning" code.....Have you tried moving the dist any?...a little bit goes a long way on those....a 1/2 inch could be 15 degrees
 
  #19  
Old 03-27-2007, 07:56 PM
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Default RE: '98 GMC Sierra with engine problems

What I thought I saw and what I saw were evidently 2 different things- wife took it in this morning - had misfire codes on it - he said he had to look atthe cap and wires3 times . #6 and #8 wires were crossed - and it had some other codes that cleared .He also changed the fuel filter I had bought and had on the seat. But at least I got the gaskets changed myself or that would have been one 'spensive bill. It was only $50 . Whew!!!!!!!!
 
  #20  
Old 03-28-2007, 09:11 AM
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Default RE: '98 GMC Sierra with engine problems

So she purrs now??..Great!
 


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