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mrvette 12-11-2021 2:43pm

Another dum engine question......
 
An old buddy says impossible......BUT is it possible for a FI engine, 350 chebby direct port.....to fire/run rough as HELL with the dizzy 180 out????

this is DPFI 8 injectors, early 90's batch fire....computer ignition.....


:dance::confused5:

Mick 12-11-2021 3:18pm

If you reverse the positions of the plug wires, I think the answer is yes. With the plug wires where they are supposed to be on the distributor, I'm thinking no.

ZipZap 12-11-2021 3:42pm

Quote:

Originally Posted by Mick (Post 1927442)
If you reverse the positions of the plug wires, I think the answer is yes. With the plug wires where they are supposed to be on the distributor, I'm thinking no.

Wouldn't the cam be screwed up? Can't imagine the valves being in a position where it would run.

Don Rickles 12-11-2021 5:19pm

Yes

Stevedore 12-11-2021 5:22pm

The distributor runs at half the RPM of the crank, so 180 deg on the dist is a full revolution of the crank. So the spark would be firing near the top of the exhaust stroke, rather than the compression stroke. I can't imagine that it would run at all; maybe some firing of unburnt fuel while cranking?

Unless I'm wrong, of course.

mrvette 12-11-2021 6:07pm

Well, obviously I am at my wit's end.....

engine starts immediately, but runs like shit.....as it warms up, it gets worse.....

DJCrit says the valves are outta adjustment.....

AND of course my ancient code reader is a gonner.....need another one....OBD1 reader.....

Kant win.....:sadangel::confused5:

DJ_Critterus 12-11-2021 6:10pm

Quote:

Originally Posted by mrvette (Post 1927440)
An old buddy says impossible......BUT is it possible for a FI engine, 350 chebby direct port.....to fire/run rough as HELL with the dizzy 180 out????

this is DPFI 8 injectors, early 90's batch fire....computer ignition.....


:dance::confused5:

yes. It's possible.

DJ_Critterus 12-11-2021 6:11pm

Quote:

Originally Posted by Mick (Post 1927442)
If you reverse the positions of the plug wires, I think the answer is yes. With the plug wires where they are supposed to be on the distributor, I'm thinking no.

It will run rough. I have made that mistake before...well...somebody else did who insisted he was right and don't argue with dad or friends or they takeyou off the "crimmus Card" list.

Datawiz 12-11-2021 6:12pm

Junk it and buy a C8. :datawiz:

Stevedore 12-11-2021 6:23pm

You're certain that the cam/valve timing is set correctly, and the firing order is correct?

Strats-N-Vettes 12-11-2021 6:23pm

Quote:

Originally Posted by datawiz (Post 1927477)
Junk it and buy a C8. :datawiz:

:Jeff '79:

mrvette 12-11-2021 7:38pm

Quote:

Originally Posted by Stevedore (Post 1927478)
You're certain that the cam/valve timing is set correctly, and the firing order is correct?

The machine shop did the short block assy.....so I ASSume the cam timing is korrect.......they guyz seem to no watt they are doin'......

SO.....IF I have that dizzy in 180 out.....my FAR OUT questin IS can the engine run at all......an old hot rodder mopar buddy says NO.....but he/I come from the Carb daze yet.....and bekause it is DPFI and so the pissers are out of sink with the general operation....mutch less the spark.....could it run and REV rough but make no power to actually run the car???

at this point is grasping at straws.....obviously....and danm well sick and tired of the project.....damnit....:issues::sadangel:

73sbVert 12-11-2021 7:46pm

Just send it to me and be dun with it!! CASE CLOSED!!

Steve_R 12-11-2021 7:50pm

Quote:

Originally Posted by mrvette (Post 1927501)
The machine shop did the short block assy.....so I ASSume the cam timing is korrect.......they guyz seem to no watt they are doin'......

SO.....IF I have that dizzy in 180 out.....my FAR OUT questin IS can the engine run at all......an old hot rodder mopar buddy says NO.....but he/I come from the Carb daze yet.....and bekause it is DPFI and so the pissers are out of sink with the general operation....mutch less the spark.....could it run and REV rough but make no power to actually run the car???

at this point is grasping at straws.....obviously....and danm well sick and tired of the project.....damnit....:issues::sadangel:

So turn it 180* and see what happens. Only takes a few minutes at most and won’t hurt anything.

Stevedore 12-11-2021 9:55pm

Get cyl # 1 at top dead center with both valves closed, take off the distributor cap & see if the rotor is close to where the #1 plug wire is connected. That'll tell you if you're 180 off or not.

Rikki Z-06 12-11-2021 10:10pm

Another suicidal thread, is this a marine engine that turns opposite of a passenger car engine? This is all I can think of? :toetap:

markids77 12-11-2021 10:36pm

Take the rest of the weekend off... rest your back and clear your mind. Then back to pure basics. It runs so you probably have sufficient fuel. Pull the plugs and do a compression test... this will tell you if the valves are really misadjusted. Then roll it around to #1 TDC and see if the rotor points to #1 on the cap. Check the 18436572 part too. Look for plug wire ends which have pulled out of the cable. Make sure the dizzy cap is not cracked or corroded to shit or the center electrode is gone. Are you running a HEI distributor? If the internal black thing (can't remember the proper name right now) has failed it will run badly, or not at all. Have you set the timing and checked for actual advance as the revs rise? I suspect you have one or more basic items which are awry so start from the baseline tuneup again.

EDIT... you DO have a dedicated ground cable from the block to the frame, right?

ZipZap 12-12-2021 12:42am

Still don't know how an FI motor would run like this. The injectors and valves would be out of sequence. On a carb engine, you might get it to start, but the timing would be far off, and when you hit the accelerator, the timing would go the wrong way.:confused5:

ZipZap 12-12-2021 12:45am

Quick check... Pull the plugs and see if any are fouled. I know you said it came from the shop, but I would do a complete timing check at TDC, as well as checking the firing order again. It may be as easy as the plug wires being messed up.

TheHammer 12-12-2021 7:50am

drop in an EV conversion kit gramps


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