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Old 06-15-2008, 10:45 PM   #1
eadacorp
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1984 crossfire backfire hesitation / flooded cylinders

ok listen up i need some help please!!!

Recently my 84 crossfire injection vet accuired a hesitation only when you floor the gas (punch it !!) if you ease on the gas it seem ok, but when floored it stalles and backfires through reat throttle body.

new plugs, wires, cap rotor, oxgen sensors, map sensors, tps voltage correct, new fuel pump, egr valve, new cat converter.

now the codes will not read from snap on computer or shorting a+b test pins on acl conn, (failed to connect) check engine on all time. The engine seem very underpowered, plugs are black but not wet.

i have not changed tbi diaphrams yet but inpected them and are a litty rough looking but that dont explain the computer prob. i even swaped ecms with a spare from my old cavailier (same part number) that i know is good, just swapped my prom and still get same prob.

during the proscess of inspecting the diaphrams somehow the fuel kept flowing in the cylinders and hydrolocked the engine with fuel ,so it wont crank over but i never run it so i pulled all plugs and changed oil, i haven tried to stert in because i wanted to let cyl air out for a day or to first. so it should not of harmed anything.

so any ideas on the computer not reading, low power, skip ect.

if anyone know what 2 wires on the ecm itself i can short together to read codes instead of acl conn in case broken wire between test conn and ecm.

also before i try to restart it is there anything i should do like wd40 in cyl or anything after cylinders were flooded.

shifts ok and good spray from injecters so i doubt the prom could be bad!!
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Old 06-15-2008, 11:00 PM   #2
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Did I miss Fuel Filter in that list?
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Old 06-15-2008, 11:13 PM   #3
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yes

yes i changed the fuel filter,.......forgot it in the list.
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Old 06-15-2008, 11:20 PM   #4
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try here www.crossfire.webhop.net
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Old 06-15-2008, 11:29 PM   #5
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dont work

that site dont seem to be active anymore.
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Old 06-15-2008, 11:42 PM   #6
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You indicated that there was low power and a backfire, that sounds like it may be a timing issue. Since the distributor is controlled by the ECM, there may be a problem with the computer controlled advance mechanism in the ECM. You also indicated that you can't read codes any longer, this also indicates that your ECM may be defective. I would look into trying an ECM from an 84 and see if it runs better. The ECM is located under the dash on the passenger side.

One more thing to check is the distributor timing. Unplug the distributor advance wire that comes off of the distributor connector and check timing. The connector is located right next to the master cylinder and is a one wire brown slide connector.

A great place to get advice is from these guys at the Crossfire injection Vault. Look for a guy named Buccaneer and he'll be able to steer you straight.

http://www.crossfire.homeip.net/index.php?
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Old 06-15-2008, 11:55 PM   #7
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i will check that

i will check that first thing in the morning, i did notice a wire on the rotor cap labeled tach that is not connected but the tack seems to be ok.

should the timing be 0 or like 4 btc

also the timing bolt dosnt look like its ever been moved, but can wear cause excessive change in timming, the car only has 74k on it.
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Old 06-16-2008, 12:01 AM   #8
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Stock timing on an 84 is 6 btdc, but i bumped mine up to 8 for a few more ponies. The bolt may not be loose, but I have seen distributor's timing drift when you put on a new cap and rotor. I can't recall whether or not my tach plug had a wire connected to it or not.
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Old 06-16-2008, 12:12 AM   #9
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The Tach wire is a white wire that first runs to a filter capacitor. Don't need the capacitor IMO. Does your timing seem to bounce around when you go to set it? If it does, I would check my balancer. Sounds like your is stock. Its a 24 year old car and the balancer is made up of 2 rings. The center ring will move in relation to the outer. Result is that you THINK you're setting the correct timing, but you're not.
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Old 06-16-2008, 10:22 PM   #10
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timing ok

well the timing is ok, but when i unplug the wire it dont change anything......timing stays the same..

directly at the ecm, cut wire to where the check eng light goes brw/wht and cut the wire at ecm... light goes out. computer still wont read codes with snapon or shorting a@b pins......i know the ecm is ok because it was swapped with one that is deffinetly good and did the same thing, however i swapped the prom, what is the chance that the computer wont read if the prom is bad.

also there is a couple of wires dissconnected ( cut) to the right and obove where the passanger right foot would be but cant find where they went to. pic attached





also there is a group of 3 or 4 orange wires in the ecm harness that someone spliced together but cant find where they originaly went to before being connected together. But it has been working untill this year.

Also maybee i would be better changing over to a carb, and get rid of the computer mess, if anyone has instructions to go to carb from crossfire may be of some help also i realise a kick down cable will be required but can i use the same fuel pump and distributor or must i change to a vac advance., if i decide to go that route.
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