okay lets see if we can fix this detonation issue

so i recently had to rebuild the bird because an exhaust seat fell out and, well, blew the motor up.

anyway, i used my other block, stock crank and rods with cp pistons. the head is stock with a bo port 1.1 cam and some mild gasket match porting on the intakes. the car is running a stinger 3 to 2.5 dual exhaust, no cat, and a cone filter with a manual boost valve.

the car is set at about 18psi and i have tried the timing at 10, 11, and 12 but i still get detonation at 3500-4k in 3rd 4th gear. i disconnected the knock sensor to see why it was "being held back" at the listed rpm. indeed the motor was pinging so the ks was doing its job.

i've run fuel pressure tests and found it makes 30psi with vac hooked up 40 without and at full boost its right about 56-58.
should i assume the fuel system is fine?

i just installed a wb sensor and its idle is around 14.5-15.2 it seems to move around a bit.
at wot it is in the low 12's to high 11's.
obviously detonation is a timing / lean problem but i just can't see pulling more time than what it was from the factory. i am running premium fuel and it has detonated on the last 2 tanks from different stations.

how about the vam? can it cause problems of detonation in any way that you have heard of?

i did a few hours of searching and found a copuple threads where people have had issues in the 3500-4000 range but with no solutions.

should i just buy a 255 pump and kirban and bump the fp. maybe i need to have my injectors flow tested? i really don't want to dump piles more money into the car, heck i talked my wife into letting me buy it because its a "gas thrifty" 4 cylinder and it has been doing nothing but costing me buku bucks. i already need to change out a steering poump that i just installed 4 days ago (it sounds like a jet aircraft).

any help would be appreciated
thanks joe

When I had a similar problem I did everything you have and more. Turns out it was a hole in the lower IC hose, mostly hidden by the clamp. New hose and no problem. Take all the IC and VAM hoses OFF the car and inspect completely. Check any other source of unmetred getting into the intake tract.

i'll check them again.

ic hoses and vam hose all looked good.
i did pull the pcv agiain and could blow air through both sides. can a bad pcv cause preignition?

also i disconnected the egr when i did the rebuild. i still have the hose and valve. should i reinstall it? under boost the egr shouldn't be functional anyway right? i can't see that being the issue.

Holding the PCV straight up and down and trying to blow through the small end, You should not be able to blow ANY air through it. Use only the Motorcraft PCV, Ford P/N: E5ZZ-6A666-A. The Motorcraft box will also have EV-127-A on it. Other brands are not made to keep boost out of the crankcase. This can cause high crankcase pressure. This may mean more oil is burned than normal. Burning oil can cause detonation.

The EGR only open under certain, limited conditions. I believe it is normally not open under boost. It is also helpful for better gas mileage

okay, so i built my own pcv using a check ball and some brass fittings and took the car for a ride. no change. i also turned the boost valve 1/2 turn back. no change. the ks is still pulling time bc of detonation.

i pulled codes. KOEO 11, KOER i got 34 77 and 74 i think thats what it was. they can be ignored bc i didn't tap the brake or "goose" the throttle.
tomorrow i will reinstall the egr and see what happens.
i am getting quite frustrated bc my 87 ran like a total champ, and it was beat. it pulled to full 18 psi with no issues ever.

btw i pulled the plugs twice today and none seemed more lean than another. i checked and rechecked gap at .034.
????????


i also cleaned out the valve cover breather while i was at it, to maybe clear out some residual oil.

well aside from having my injectors cleaned and flow tested and/or going to a meth kit i am out of ideas.

i tried to set base time at 8 deg but it was way down on power so i went back to 10.

there are no chassis dynos around here for me to see about getting a custom tune nore can i afford that right now. so........
?
anybody have any ideas?

who has experience with a methanol kit?

maybe with the open exhaust higher boost better air filter and cam its just too much for the factory tune to manage?

maybe with the open exhaust higher boost better air filter and cam its just too much for the factory tune to manage?

I don't see anything in your tune that the factory EEC can't handle. A lot of us have had what you have and more and the factory EEC handled it just fine. I'm still betting on an air leak some where.

On the noisy new PS pump. Did you get all the air out of the system, that really makes them noisy.

See http://natomessageboard.com/cgi-bin/ulti...792#000005

well there just isn't that much in the intake system that can leak. the vam hose holds air pressure. both ic couplers hold air pressure.
the motor was rebuilt completely and all gasket surfaces were cleaned with roloc discs and nice new felpro gaskets used.

riddle me this though. assuming there is an air leak. under boost, say 20psi, wont the air leak be reducing air into the combustion chamber rather than increasing it (bc its blowing out of the sealing surfaces rather than sucking extra air). its only in 3rd and 4th gear under heavy pulls.

as far as the ps pump. i've tried it all. vaccuum bleeding and turning the wheel back and forthe a million times, flushing the system 3 or 4 times.. i just think the ac delco reman pump is crap.
any idea how to get ahold of a for rebuilt unit? my local dealer is worse than a parts store with a 17 year old kid behind the counter with no auto experience.