worst question ever!!

Neo

Neo

New member
Hi gang,
I have some trouble to find the right answers to my problems,so maybe you guys can help me out with this:
In my manual(GM full size trucks,they don't give much details about the MFI turbo engine) the firing order for an 4.3 is:1-6-5-4-3-2
is that correct?cause the motor isn't idling well,and has serious lack of power!
I didn't introduce myself,but the truck is a stock SY with front mount intercooler.
 
Last edited:
sytyguy

sytyguy

Moderated User
Re: worst question ever!!

Correct - 1,6,5,4,3,2

The norm is to try and get the distributor where #1 is pointing at the #1 cylinder (front driver side), but as long as you have the firing order right, you can drop the distributor in another position and just reroute wires.

HTHs

Hood
 
Neo

Neo

New member
Re: worst question ever!!

Thanks a lot for your help :tup:
I'm going to take the compressions now,i adjusted the timing(0°),but idles bad now(oscillates from 650 to 950 RPM),and it's like the motor is running on 4 cylinders :( ,when i open to full throttle it hesitates a while before going to full rev...
,maybe i'll try some new plugs !
 
Mtn Z

Mtn Z

Donating Member
Re: worst question ever!!

Or spark plug wires swapped. Mine chopped and all that fun stuff when I had 3 and 4 swapped on the distributor cap.
 
9

92Typhoon1679

Member
Re: worst question ever!!

Ignition is probably the biggest problem maybe spark plug wires i installed ATR headers and had a terrible time with burning wires but i had almost the same problem as you then i replaced my distributor with another one and it helped the other one looked ok but didnt run ok. ive tryed changing out ignition modules too but the distributor was the problem all along.
 
SY2932

SY2932

Administrator
Re: worst question ever!!

Neo said:
Thanks a lot for your help :tup:
I'm going to take the compressions now,i adjusted the timing(0°),but idles bad now(oscillates from 650 to 950 RPM),and it's like the motor is running on 4 cylinders :( ,when i open to full throttle it hesitates a while before going to full rev...
,maybe i'll try some new plugs !
Click to expand...

Don't forget to disconnect the wire under the dash on the passenger side when you set the timing too:

"The ESC Electronic Spark Timing "tan wire with a black stripe" that everyone can't find when attempting to set their timing (s-series). Wire is under the carpet on the passenger side below the heater box. It is disconnected to set the timing, then reconnected."
 
Don W.

Don W.

Stab it and steer it
Re: worst question ever!!

IMO Serious lack of power is not a plug wiring order issue. Believe me you'll know it if you have a pair out of sequence. Now timing, that definitely can be an issue, as mentioned just above. Don't forget, after resetting timing, to pull your ECM fuses for 30 secs or so.
 
Neo

Neo

New member
Re: worst question ever!!

Don W. said:
IMO Serious lack of power is not a plug wiring order issue. Believe me you'll know it if you have a pair out of sequence. Now timing, that definitely can be an issue, as mentioned just above. Don't forget, after resetting timing, to pull your ECM fuses for 30 secs or so.
Click to expand...
Can i just disconnect the battery for 30 secs??I resetted the timing after disconnecting the wire,and it's running a lot smoother now,and it have a better response too.
the stock turbo can handle some extra piping and a large intercooler ,right?
 
Neo

Neo

New member
Re: worst question ever!!

Damn...there's still a problem remaining with this f****n' engine when i turn on the A/C it's like the motor is going to die...
Someday i'll find out what's wrong with it,...someday :(
 
Don W.

Don W.

Stab it and steer it
Re: worst question ever!!

Yes you can disconnect the bat. You'll loose the radio presets. Not sure on the AC issue, but I seem to remember that a new IAC can cure many idling issues.
 
Neo

Neo

New member
Re: worst question ever!!

Hey guyz,
Seems there's a head gasket blown,so i'm taking off the heads,where can i find some inforced gaskets,and timing chain?
And what do you recommend to replace aswell?
Greetz ;)
 
gjp

gjp

another post whore
Re: worst question ever!!

you sure its a blown gasket. The gaskets in these trucks hold up well.
 
gkrcr882

gkrcr882

SyTyless......for now!
Re: worst question ever!!

If the ignition system had been gone through (timing, plugs, cap & rotor, coil, wires, etc), it may be a fuel injection problem as well, such as low FP, or a bad injector or two. Might have a sensor out of whack somewhere as well.
 
jjorgensen52

jjorgensen52

NHSTE - I'm the only one!
Re: worst question ever!!

Neo said:
Hey guyz,
Seems there's a head gasket blown,so i'm taking off the heads,where can i find some inforced gaskets,and timing chain?
And what do you recommend to replace aswell?
Greetz ;)
Click to expand...
If you're going to have the heads off, probably should do valve seals. Also, might not be a bad time to check the lifters ... or add some roller rockers :tup:
Use a double roller timing chain for a small block... mine is edelbrock if I recall

Also, a good source for strong gaskets is SCE Gaskets, Inc ... head gaskets, also the trucks came without exh. manifold gaskets on them from the factory, but if you plan to add some that is the place to get them
 
Neo

Neo

New member
Re: worst question ever!!

gjp said:
you sure its a blown gasket. The gaskets in these trucks hold up well.
Click to expand...
I presume that a gasket is blown :i haved an oil service like last week and there's a lot of white emulsion inside the valve cover when i took off the cap saturday :(
the motor is running bad aswell(like it's running on 4 or 5 cylindres)and still lack of power,by the way,the turbo press is around 0.4 bars...i don't think this is normal service pressure?
And thanks for the tip jjorgensen :tup:
 
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