First off how do you unhook the EST I can't find a tan/black wire that Hayes says to detach? I can't use a timing light on it.


Still having smoking problems they got worse, and now puffs at idle and misses at idle. All 8 plugs look the same. When it starts a cloud twice the size of the Suburban puffs out.

Now I have a Jegs (MSD) coil, cap/rotor, and cables. Nice quality for the price. I replaced the regulator with a Jet regulator and purchased the Jet 6 pack, both helped a little but not much. I also replaced the IAC, ITC, and Map sensor. I tested the tps and it read good. Gas fumes while driving are now reduced, but..

I am only getting about 13.5-14mpg highway before it done way better. I have a K&N, Flowmaster exhaust, TBI spacer, mild exhaust porting. Engine was rebuilt 7000 miles ago and ran good at first and slowly degraded. No signs of bad rings, no oil use or oil on the plugs.

Looks like the intake manifold may be leaking in the rear (lifter valley) you think it could be the problem?

If it is sucking air then it could cause the problem. The timing connector is under the dash just below the glove box, black and tan wire.

Sure is in the dash, my book said in the relay cover. That helps alot.

Glad to here the intake could be the problem.

What kind of mpg you think it will get when right, I am also wrapping the manifolds and putting on an electric fan.

You think 3.42 gears would help mpg with mainly highway miles? How about roller rockers? Only other thing I can think of is underdrive pulleys and I don't like that idea.

I like the Suburban so I want to stick with it and make it as good as possible.