problems with a 89 suburban(tbi)

78blazer454 · August 13th, 2009, 06:28 PM

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well my friend bought a suburban and it smoked alot and ran realy bad.
well so we rebuild the topend of the 350(new heads, new head gaskets, new cam)the worst was the heads where cracked. so it stop smoking, but it ran with a high and low idle. IT has no power, at all, it wont climb up a curb, we tried going to go up a dirt hill size of a drive way and it would just have full trottle at low rpms and the tires do not move.
we got up it finally in lowest gear in the tranny and the 4x4. on the streets it will work its way up to 45 and top out. it has no torque at all. in idle it can reach high rpms but in drive it cant.

we did change out the fuel pump, filter, egr value, co2 censor, and a used trotle body.

what do we do.

__________________
78 Chevy k5 blazer Specs
70 chevy 2wd lwb(dreaming of it being a desert runner swb)
84 k5(soon to be cabin rig/hunting rig)
"Experiance is a hard teacher she gives the test and the lessan after word."

Last edited by 78blazer454; August 13th, 2009 at 06:29 PM.

**Cricket** · August 13th, 2009, 10:24 PM

Did it throw a code/SES light? Have you attempted to retrieve any codes?

Any vacuum leaks?

What's the fuel pressure reading?

What does your injector pattern look like?

Did you set the timing correctly?

Did you use a stock set of heads, cam, et. Any mods made during the rebuild?

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Quote:

Originally Posted by Mr. Berry

I've never had a bad day in my life....

**filo** · August 14th, 2009, 10:44 AM

Quote:

Originally Posted by 78blazer454

but it ran with a high and low idle....

did it sound all right?

Quote:

Originally Posted by 78blazer454

in idle it can reach high rpms but in drive it cant.

Does it take full throttle and a few seconds to get there?

Quote:

Originally Posted by 78blazer454

we did change out the fuel pump, filter, egr value, co2 censor, and a used trotle body.

Have you checked for fuel pressure and volume?

__________________
1986 Chevy K5 Blazer Specs
'88 Chevy K3500, 4x4, TH400, 454 TBI. 3" body lift and 3" single exhaust. Otherwise all stock

Quote:

Originally Posted by Cricket

Most are on the Internet making Facebook love or Twittering their nutsack.

?Perseverance is the hard work you do after you get tired of doing the hard work you already did.?

78blazer454 · August 14th, 2009, 06:33 PM

well i didnt deal with the codes, his dad did.
He doesnt have a fuel pressure gage so not sure.
The heads where rebuilded ones and stock.
The cam was slightly not stock.
I dont know how to messure vaccum leaks, but we got some new vaccum hoses.
We did time it and it was on time.
It takes full throttle but it just has no response and it takes a while to get there.
It sounds find but it idles down and them come back to a good idle.
one injector does have a little drip when its spraying. I know it will fix some problems but i dont think it will be a big notice.
He did have a local shop try to find the problem and they just told him what to replace and thats it. we did the work and nothing changed.

I dont know that much about a tbi, i dont know how they work.

__________________
78 Chevy k5 blazer Specs
70 chevy 2wd lwb(dreaming of it being a desert runner swb)
84 k5(soon to be cabin rig/hunting rig)
"Experiance is a hard teacher she gives the test and the lessan after word."

Last edited by 78blazer454; August 14th, 2009 at 06:47 PM.

**Cricket** · August 14th, 2009, 06:57 PM

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Quote:

Originally Posted by 78blazer454

well i didnt deal with the codes, his dad did.
He doesnt have a fuel pressure gage so not sure.
The heads where rebuilded builds and stock.
The cam was slightly not stock.
I dont know how to messure vaccum leaks, but we got some new vaccum hoses.
We did time it and it was on time.
It takes full throttle but it just has no response and it takes a while to get there.
It sounds find but it idles down and them come back to a good idle.
one injector does have a little drip when its spraying. I know it will fix some problems but i dont think it will be a big notice.

I dont know that much about a tbi, i dont know how they work.

TBI is very sensitive to cam change, the OBD1 system cannot compensate if the change in lobe seperation is too large - without reprogramming the ECM prom chip. You may want to contact Brian at tbichips.com and talk to him. He can tell you if your cam specs require the prom chip to be reflashed for the new cam. If not then the problem is elsewhere.

The TBI is essentially a simple minded wet injection system. Like a carb but with electronically metered fuel based on key sensor readings and pre-programmed data. The parameters are very tight with the generation 1 or OBD1 TBI system. Imagine Forrest Gump with his shoelaces tied together trying to run. That gives you a perception of what happens when you ask the OBD1 to adapt to modifications without a new chip. If I remember correctly the generation 2 OBD2 started around 1994 and could handle modifications better because you could reprogram parameters via a scanner.

With OBD1 even a simple change in exhaust pressure from adding headers can create a consistent code light unless the little chip in the ECM is reprogrammed (flashed) with new data tables for backpressure readings at the EGR.

__________________

Quote:

Originally Posted by Mr. Berry

I've never had a bad day in my life....

78blazer454 · August 14th, 2009, 07:17 PM

oh, so it needs to be chiped, for the size of the cam.
well the chech engine light does come once in a while.

__________________
78 Chevy k5 blazer Specs
70 chevy 2wd lwb(dreaming of it being a desert runner swb)
84 k5(soon to be cabin rig/hunting rig)
"Experiance is a hard teacher she gives the test and the lessan after word."

Last edited by 78blazer454; August 14th, 2009 at 07:20 PM.

**Cricket** · August 14th, 2009, 09:02 PM

It depends on how different the cam is from the original.

__________________

Quote:

Originally Posted by Mr. Berry

I've never had a bad day in my life....

78blazer454 · August 15th, 2009, 09:09 PM

ok, i will tell him to do that.
thanks.

__________________
78 Chevy k5 blazer Specs
70 chevy 2wd lwb(dreaming of it being a desert runner swb)
84 k5(soon to be cabin rig/hunting rig)
"Experiance is a hard teacher she gives the test and the lessan after word."

springer · September 15th, 2009, 05:09 PM

Are you guys getting a backfire or a pop up through the tbi. If so you are not getting enough fuel. Just like cricket said get a chip burnt and I will stand behind tbichips.com, he is great and knows his stuff. Although if this thing is just a dog with no power it sound like timing to me. Did you guys unplug the wire before you set the timing?

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1986 Chevy K5 Specs

78blazer454 · September 16th, 2009, 09:03 PM

its not backfiring and i think its getting enough fuel (new fuel pump)and we did time it and it was on time, we did not unplugged it.

He figures that hes going to sell it and not get something so new and go with a carb and mybee even a blazer or a pickup this time.

__________________
78 Chevy k5 blazer Specs
70 chevy 2wd lwb(dreaming of it being a desert runner swb)
84 k5(soon to be cabin rig/hunting rig)
"Experiance is a hard teacher she gives the test and the lessan after word."

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