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86 2 door Blazer 4x4, 2.8, 4 speed manual
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Discussion Starter · #1 ·
I've got an 86 2 door blazer 4x4 2.8 4 speed manual thats not running well at all. Has a fuel smell while running so it's obviously running rich. Has new plugs, wires and distributor cap. It's only throwing a 32 code for egr as I don't have any vacuum lines going to the egr solenoid. They are capped off. Timing is at 14° and plugs are gapped to .040". Ive owned a hand full of 4.3s in the past but never a 2.8 and this thing just has no power. Especially with the AC running. I just bought this blazer and had to throw the front accessories on and the tbi. So I don't have a very good known history with this engine. Odometer shows 130k. I have drove it for a couple weeks now and havent gotten anywhere with getting it figured out. Fuel mileage is only 13-14 mpg. I figured it would be better than that. I do have an ALDL cable and the WinALDL software and can run a data log if anyone could look at it for me and possibly help me out. While running the WinALDL i noticed it idles at 1200 rpm if it gets lower to around 1000 it will stumble and die. A vacuum gauge off the intake bounces around like crazy while it's idling but held at a stead speed above idle the vacuum need is very steady. Anything you guys can think of to help me out?
 

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Been there Done it
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If your vacuum gauge isn't steady, you likely have a vacuum leak.
 

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86 2 door Blazer 4x4, 2.8, 4 speed manual
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Discussion Starter · #3 ·
No vacuum leaks, I've checked that again. It had one after I first got it put together. One vacuum cap from the throttle body had actually been pushed off the nipple on the throttle body. Put a new one on and zip tied it and it hasn't come off.
 

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Boozebag
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Does this rig still have a cat on it? If so, check that for a partial blockage.
Just for the best results, change your fuel filter too - if you haven't.
Air filter clean? A former friend had a Ford Ranger and couldn't figure out why it got terrible fuel mileage and had no power.
I have never seen an air filter so plugged. Anyway, changed it and the truck ran super.

People are always ready to blame the ECM for problems, they are pretty rugged.

Reach under the EGR body and push up on the diaphragm with the engine running. Does it stall? That should tell you that the diaphragm isn't stuck or partially open.

Although super rare, your brake booster may have a leak. Brakes work ok?

Check your timing chain for slackage. I guarantee it's sloppy with 130k miles. Pop the distributor cap. Turn the front pulley in one direction and watch the rotor move. SLOWLY turn the front pulley and watch the rotor. Does it take half a turn of the pulley for the rotor to move again? Ha.

A compression test may also be helpful. Most of these engines have 125 Lbs/per cylinder. You may find a dud or low compression.

Just a few problems to look for.
I'm grabbing for straws, but one of these may be your solution.
Or maybe a combination of them.

Hope this helps...

Confucius say: Low power mean big mystery... :p
 

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I've got an 86 2 door blazer 4x4 2.8 4 speed manual thats not running well at all. Has a fuel smell while running so it's obviously running rich. Has new plugs, wires and distributor cap. It's only throwing a 32 code for egr as I don't have any vacuum lines going to the egr solenoid. They are capped off. Timing is at 14° and plugs are gapped to .040". Ive owned a hand full of 4.3s in the past but never a 2.8 and this thing just has no power. Especially with the AC running. I just bought this blazer and had to throw the front accessories on and the tbi. So I don't have a very good known history with this engine. Odometer shows 130k. I have drove it for a couple weeks now and havent gotten anywhere with getting it figured out. Fuel mileage is only 13-14 mpg. I figured it would be better than that. I do have an ALDL cable and the WinALDL software and can run a data log if anyone could look at it for me and possibly help me out. While running the WinALDL i noticed it idles at 1200 rpm if it gets lower to around 1000 it will stumble and die. A vacuum gauge off the intake bounces around like crazy while it's idling but held at a stead speed above idle the vacuum need is very steady. Anything you guys can think of to help me out?
If its if you have a Rochester carburetor get rid of it they're horrible for the 2.8 had the same problem with my 84 so I bought the Weber conversion kit made by Redline it's amazing a lot more power and a really smooth idle and this carburetor also makes it able to delete all your EGR stuff
 

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B4U Task Force Admin
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If its if you have a Rochester carburetor get rid of it they're horrible for the 2.8 had the same problem with my 84 so I bought the Weber conversion kit made by Redline it's amazing a lot more power and a really smooth idle and this carburetor also makes it able to delete all your EGR stuff
Check your punctuation keys...they appear to be in-op.
 

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Awww..you ain't got shit!
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Check your punctuation keys...they appear to be in-op.
I "think" this may be what he was trying to say

If you have a Rochester carburetor you should consider getting rid of it. They're horrible for the 2.8. I had the same problem with my 84, so I bought the Weber conversion kit made by Redline. it's amazing. It gives the truck a lot more power and a really smooth idle. This carburetor swap also gives you the ability to delete all your EGR stuff.

What is this war on punctuation over the last 5 years or so?? It's so hard to tell what anyone is actually saying!
 

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Awww..you ain't got shit!
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@madmax . Gotta say that I've seen air filters plugged like that myself. People don't realize that the fuel for vehicles is actually free. It's called air. An engine is just an air pump. Gasoline is only a catalyst for air combustion.
 

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86 2 door Blazer 4x4, 2.8, 4 speed manual
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Discussion Starter · #9 ·
Egr is disconnected and when idling and pushing on the diaphragm is stumbles and dies. Brakes work good. I removed the cat and put in a straight pipe. That helped very little. Air filter is new and fuel filter is new. Plugs, wires and cap are relatively new. I have a parts blazer of same year I swapped ecu and injectors and still doesn't help any. By what I can tell the o2 sensor is working like it should by looking at the live data on my laptop. I'm going to try a new coil tomorrow since this one looks original. I've used the AC the last couple days and when the clutch is engaged there's an even bigger lose in power. When coasting and the ac compressor engages it feels like I'm slightly hitting the brakes. Still has a raw fuel smell at idle and when driving around town. I can hardly get up to 65mph with it. If there's a head wind I'm lucky to hit 55mph
 
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