# 1987 HB eating to much fuel



## sirscottalot (May 22, 2009)

Hi I'm new to the post but have been reading this forum for some time.
I have an 87 D21 that I bought for my son. It has the z24 engine and 5 speed. The truck had a hard time passing Cal smog with high nox. We gave it a tune up with new plugs, cap, rotor, PVC valve, new o2 sensor, and a new egr valve. We also used seafome to clean out the carbon and checked the egr tubes and openings for any build up. We finally got it to pass when we added some gas additive for passing smog so I'm sure I still have a nox problem. My son brought the truck back to me and said that the truck is getting very poor gas mileage and running poorly. I checked his codes and got a 44 but I noticed he was getting a timing chain noise. I changed his timing chain and that want well. But the problem still remained. I checked codes again and got a temp sensor code so we changed the temp sensor and replaced the broken connector to the sensor. Checked codes again and got a crank angle code. Found the coil wire arcing and fixed that. Made sure both coil are working. Cleared the code and now have a 44 but still the poor gas mileage. So poor it eats up the cat. I'm now lost and need your help. Thanks


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## zanegrey (Dec 5, 2005)

check you injectors ..


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## sirscottalot (May 22, 2009)

Thanks for getting back to me. How do you check the injectors?


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## zanegrey (Dec 5, 2005)

as u sit in the truck to start it ,when you turn the key you hear 4 or 5 bells but just underneath that sound you hear the injectors charging. it usually is charged by the end of the fourth bell( or chime).

is your injectors charging ? are the injectors spraying all the time ?


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## sirscottalot (May 22, 2009)

It charges through all six beeps. When the beeping stops so does the charging.


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## zanegrey (Dec 5, 2005)

good ..
remove the breather cover and watch the charging process to see if the injectors are leaking ..


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## sirscottalot (May 22, 2009)

The breather cover is the cover over the injector right. Will the injectors be leaking at the base of the injector or on top of it? If they are leaking what is the best thing to do with a leaking injector, replace it, a seal kit, or running some B-12 chemtool through it?
P.S. thanks for taking the time with my problem.


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## zanegrey (Dec 5, 2005)

look down the tbi (use a screw driver to hold the buttery fly shutter and while the system is charging look to see if the injectos sharply cut off as the charging cycle quits...

this is just a visual inspection ..


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## sirscottalot (May 22, 2009)

Well I took a look and didn't see any fuel but it did sound like it was leaking. It was giving a sputtering sound from the injectors.


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## sirscottalot (May 22, 2009)

The sputtering sound dose quit as soon as the charging system quits.


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## zanegrey (Dec 5, 2005)

it should be a clean sharp spray ..use a light and look down the tbi...


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## sirscottalot (May 22, 2009)

I have been useing a light and still don't see any spray pattern. I want all around the horn of the tb and could not get a good angle to see a spray pattern. I did it with a screw driver holding the butterfly open and also tried it with it close to see if I could see anything on the butterfly, and I didn't. I did start up the truck and saw the spray pattern on the butterfly and it looked like it was gettig a lot of fuel. I will try and get a small thin mirror that I can fit down in there so I can see the opening of the injector or just see the spray.


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## sirscottalot (May 22, 2009)

I used a dental mirror and still didn't see a spay pattern. I even stuck it under the injectors to see if it would spray the mirror and it didn't. I started up the engine and stuck the mirror under the injector and it sprayed the mirror but I still can't get a good angle to see the pattern.


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## zanegrey (Dec 5, 2005)

how many miles to the gallon are you getting?


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## sirscottalot (May 22, 2009)

It was getting 22 mpg when we bought it. now it gets about 10 or less.


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## zanegrey (Dec 5, 2005)

i want to talk now about the t-chain replacement..

after replacing the timing chain did you prime the oil pump and time the oil pump shaft??


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## mitsuspyder (Feb 27, 2009)

that is normally the practice on these types of engines


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## sirscottalot (May 22, 2009)

Yes I did prime the oil pump and timed the the shaft. I read alot of theads saying how inportent it was to get the timing correct in that area. The Only reason I replaced it was because it was slapping the guides. The truck rans the same as it did after I replaced the chain.


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## sirscottalot (May 22, 2009)

Is the injector sappose to spray when charging? Could a fuel regulator cause the problem and not give off a code?


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## zanegrey (Dec 5, 2005)

yes i think so..

but you are getting too much fuel .. if it was forcing the injectors to spray too much you would get an injector code..

i mention the t-chain because being a tooth off can make it suck gas and still seem to be running good..

also check brakes for dragging or a sticky wheel bearing..


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## sirscottalot (May 22, 2009)

Unless it jumped time before I did the timing chain, I don't think it's out of time. I marked everything as far as the distributor and rotor is concern and made sure #1 was at tdc and on the mark. I installed the oil pump shaft about 3 or 4 times to make sure I had it in the same position it came out so the rotor would be in the same place as marked. Do you suggest that I take the shaft out and redo the timing or take out the 2 bolts that hold down the dist and rotate the the unit and see if it runs better? Or is there a way to find out that you are out of time even if the timing marks line up with a timing light and the idle is good.


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## zanegrey (Dec 5, 2005)

the timing light is optimum..

the 2 bolts for the dizzy is next..


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