ckyguy68

As most of you know i blew a head gasket recently on the nitrous and have since replaced it along with all new intake manifold gaskets. I had a check engine light when i first got it back together. Replaced the 02 sensors, and the light went away immediately. The car ran like poo for a little then i took a cruise and it started running really good. Well the next day it starts breaking up past 5k and develops another check engine![:@]I pulled the plugs, they were RED[&:]. Bought new motorcrafts gapped @ .054". It runs better now but it started detonating tonight when i was cruising. Only under load obviously, more noticable with ppl in the car and in higher gear. Im running 93 octane and its at 14*. Is it possible my dizzy is off a tooth? theres no reason it should be pinging..... please help me figure this out

pitman86gt

try to tdc and drop dizzy back in and reset timing.

ckyguy68

What do you guys use to find TDC? i used one of those red tubes that you put on a carb cleaner can.

notchbackmatt87

dizzy needs to be reset is my guess.

FoxGT

If you set your timing then the disty isn't off.

Was your timing set at 14 before? My friends '91 knocks at 14, but that's on '89 octane
Sure the gas is good?

ckyguy68

Thats what im saying about the timing, i dont think its possbile that the dizzy if off. Yea its never had any pinging problems at 14*. Its 93 octane, i just got it. I guess ill just have to do a MIL self test again [:'(]

aode08

let us know the codes etc.


You can also have a damaged injector, or bad o2 ground, not connected to your heads(orange wire rear driver head).

Ive seen detonation, demolish an injector's spray pattern

ckyguy68

So thats where the orange ground goes! I ended up putting both that and the firewall ground strap on the furthest back upper intake bolt because i couldnt remember where they went. The one with the stud for that bar that goes to the lower. Can someone explain the more grounds and what that bar is?

stanguy306

Whats up CKY? Yeah that orange ground is for the ecu I believe...nonetheless you have it in the right spot...intake bolt or trans bolts doesnt matter as long as it on the motor...did you clean the ends? Sometimes they are covered in mad oil/grime etc. only time my car broke up in high R's it was cap n rotor related or plugwires bad connection...did you check all the "stupid" things?

aode08

the orange wire is not the computer gound, it is the ground for both O2 sensors. THE STRAP goes to the driver rear tranny bolt, the orange wire - to the firewall with the strap or rear of heads. this is crucial and for saftey, I would run a 4 ga ground wire from the battery to the firewall.