I GIVE UP!!!!!!!!!!!!

Does anybody want to buy a POS 91 notchback with H/C/I and a brand new blower that just detonates ALL the time!!!!?

I am nearly out of things to try. This may be a long post b/c I'm going to try and list everything I have checked/replaced/altered so I apologize in advance.

I just installed a new Novi 1000 along with the blower related pieces listed in my sig. But something is wrong with either the motor or electronics of my car b/c it will not stop pinging. I had it dyno tuned with a custom SCT chip burned and it did fine on the dyno. Then we get it off the dyno and onto the street and it just spark knocks to no end. It still pings at part throttle about 3000 rpm and at WOT. Reading the plugs there does seem to be more detonation from the 4 rear cylinders (3,4,7,and 8).


-We first backed timing WAY down, like 9 total at 5000 rpm's.
-Then we lowered the A/F ratio from 11.8:1 to 11.0:1
-Base timing is set at 10* but the chip further alters that.
-I've pulled the chip, set base timing to like 5-6 and it still pings.
-I started off with Autolite 3924's gapped at .035, then .032 then switched to 3923's gapped at .032 (seemed to run worse with the 23's) but still pinged with any of the above combos.
-Fuel Press does not seem to be a problem as it seems to rise and keep up as I get on the gas and into boost. But I have changed it anywhere from 40-60 psi with and without the chip.
-I've checked the make sure the balancer is true to its reading
-I've swapped out the coil and distributor, no difference.
-I've bypassed my MSD 6AL, nothing
-I've checked for vaccum leaks
-I am blowing some oil out of the dipstick tube but any blowby should essentially lower my compression ratio so in essence reducing the likelyhood of detonation (I dont have a breather cap on the valve covers at this point, I am using a supra PCV valve)
-I've put two tanks of Amoco 93 octane fuel in it
-My coolant temps are not out of the ordinary (most of the time are b/t 150-200)
-I checked for kinks in the fuel lines but I really think if that was an issue the pressure would be doing some funny things.

I know there is more but I cant think of it right now. Something else that maybe will help someone give me a recommendation is that today it strangely cut off while coasting and then when going up a hill which is what has had me thinking it is electronic/wire related. It hadnt done that before though and hasnt since.

Please help me diagnose this problem! I've been working on it for 3 solid days with no sign of improvement and the blower has been on for 2 weeks and I have yet to be able to stay in the gas all the way. I'm just really getting disguiresed(SP) and running out of ideas of things to check. ANY input is greatly appreciated. Thanks, Ryan

PS Sorry for the long *** post.

Can you pull the chip and run just the standard computer??

If so, try that and set the base timing at 10 to start with........

Quote:

---

Originally Posted by 5150 LX

Can you pull the chip and run just the standard computer??

If so, try that and set the base timing at 10 to start with........

---

Never mind, I see that you have.......... :confused:

Quote:

---

Originally Posted by NothinButNotch

.....Something else that maybe will help someone give me a recommendation is that today it strangely cut off while coasting and then when going up a hill which is what has had me thinking it is electronic/wire related. It hadnt done that before though and hasnt since.

---

Check your 10-pin connectors, pull them apart clean them up real good and reapply some fresh dieelectric grease to them. Also check the ground wire from the injector harness, should be at the back of the intake and attach to either the head or the firewall.

Have you relocated the battery to the rear? If so, make sure that you have an extra ground wire running from the block to the frame.

How old is your fuel pump? You may want to test it to see that it is not going south on you, typically when they are it'll start dieing after it's been runnning a bit & has warmed up, maybe it's cutting out intermittently and running you lean???

Ok, what is your compression ratio? Have you tried to just run the car spout out? try 19deg or so and see if it pings. Does it ping under load or just cruising down the road?
What boost level are you running?

5150LX,

Thanks for the ideas. I did actually already mess with the 10 pin connectors. I did not disconnect them though but I have pulled, twisted, and moved them around with the car running trying to get it to act differently, no such luck.

My battery is relocated to the trunk. I'm not quite sure what you mean with running an "extra" wire. I'm assuming you mean along with the small stock one run another or a bigger one, if not please explain. But I removed the stock one and in its place have a 1/0 gauge wire running from the block to a bolt on the frame.

My Walbro fuel pump is probably 3-4 years old. How long do they typically last? I have thought about it being the culprit but the only thing that discourages me from that is that the car seems to have and keep good fuel pressure at all times. It never dips, not even when it died a couple times yesterday (I had a buddy with me who was watching gauges etc). But just incase, what is the best way to "test" a fuel pump? Or do you really mean just replace it?

Thanks again for ideas, I'm hoping something will pan out here VERY soon. I have not yet gapped my plugs down to .028" but at this point I really dont think that is going to help. Any thoughts on that? Thanks again, Ryan

Man it looks like you've taken care of everything that I can think of, you have the grounding correct.

Like Alex stated, have you tried running it spout out with about 19 degrees of timing locking in???

Quote:

---

Originally Posted by NothinButNotch

Does anybody want to buy a POS 91 notchback with H/C/I and a brand new blower that just detonates ALL the time!!!!?

-I am blowing some oil out of the dipstick tube but any blowby should essentially lower my compression ratio so in essence reducing the likelyhood of detonation (I dont have a breather cap on the valve covers at this point, I am using a supra PCV valve)

---

Blow-by can and will cause detonation. Excessive oil in the combustion chamber can do severe damage.

I have 2 suggestions....
1. Put a breather on the valve cover.
2. Take the chip out, set your timing with a timing light to 19 degree's total timing. Leave the chip and spout out.
It sounds like the major issue is an overly aggressive timing table in your chip. I have seen numerous cars detonate on the street and have none on the dyno. The dyno doesn't load the motor like driving on the street does.

If all else fails. I'll fly to wherever you live and give you the $100.00 dollars its worth :).

Alex,

I believe my compression ratio is about 9.2-9.5. I dont know for sure but its the stock bottom end and straight from the box TFS Twisted Wedge heads.

19 degrees total is what on balancer, 5*? And while I know oil in the cylinders will cause detonation, the plugs show no signs of burning oil and the car does not blow any smoke from the tailpipes (black or white). I think my blowby is being caused by no breather and maybe a PCV valve overly tight. I will try driving it with the spout out though just for kicks. At this point I'm willing to try just about anything. I'll drive the bastard under water if it will stop spark knocking!!!

Something else I plan to try as soon as I can get ahold of a friends processor is swaping EEC's just for kicks.

Thanks again for the ideas, Ryan

pull the spout, set the timing to 19 degrees and leave the spout out this will prevent the computer/chip from making any timing adjustments, you will be running 19 degrees all the time no matter what RPM or load on the motor.....

Well that is the first step in the right direction yet!!! But I'm trying not to get my hopes up. I just took it for a ride and with the spout out, the chip out, and the timing set at 19* it didnt ping. Could this mean I have a bad computer? A buddy just brought me over his A9P computer, same thing that is in my car, and I plan to pop it in and see what happens later on this evening. Unfortunately I have to leave right now but I wanted to post this up and get others thoughts on anything else you think it might be. Thanks again for the help, Ryan

Woot!!!!

Keep us updated!!

What injectors are you running and are you using an FMU? What is your base fuel pressure set at? How much boost are you seeing?

Eric

I have 42's, no FMU, FP is set at about 42 (vac on) for the time being, and the most boost I have seen is about 10 lbs.

I tried my buddies computer with my chip last night and still had pinging. Something that was kinda strange I thought though was that with his computer my "check engine" light came on. I didnt have time to read the codes last night. But his computer was an original (ie not a reman like mine) A9P computer which is what mine is supposed to be as well. Is it possible the timing tables in my reman EEC are just screwed up? Can that happen?

And actually who I need to write to is the guy who burned my chip on the dyno and see if when he was messing the timing tables if he could actually see the "stock" timing tables and was changing them or if he was just going off what they are "suppose" to be and lowering them at higher rpm's. Because if they are messed up or not "normal" for some reason then if he was tuning to standard timing tables that would explain why even when we had back timing way down it would still ping.

Thanks again for any more input, Ryan

I ran my Superchip, stock program, on my A9P and it pinged it's nuts off.

Was yours a mail order Superchip? This one was a custom burned SCT chip by Ed Clark on the dyno. And then he hung around for quite a few hours afterwards trying to help me figure out what was causing all my detonation. But when we got to the point where he said he STARTS most of his SC tunes and it was still pinging like crazy AND he had richened the A/F up to 11.0:1 we called it quites b/c we figured something else was going on.
And he knew it was an A9P computer, in fact thats what he said he prefered, so it wasnt a matter of that. I'm just beginning to wondering if something isnt wrong with the computer I have. But with that said, everything seemed on par when it was N/A and when I had nitrous on it. I still dont know but hope to figure it out soon. Thanks again, Ryan

Yeah, mine was just a stock A9P flashed mail order chip. Seems a lilttle bit of similarity in our computer parts. My car always ran lean when it was stock, ran good but very lean. I have to run very retarded timing with the blower. Tried locking out the timing, it didn't run very well, not as much power or throttle response. Does better at 6* and spout put back in.

Maybe trying that other A9P will fix it for you. I have a feeling it won't change anything though.

Is this a hyper motor? If so you probibly cracked a piston. Oil out the dip stick is never a good thing. Especially with only 10 #'s of boost. Oil in the combustion chamber kills the octane in your fuel. I believe that I had the same problem with my car. Could not keep a set of head gaskets on the car.
Do a leak down test and I bet thet the rear cylinders will read low. I have seen this before on a blown Impala, turned out to be a cracked piston.

Eric

Take the chip out and leave it out. Your ECM is good, too much timming. I drove a whole season with my spout out until I could afford a PMS. I had set my base timming to 19 and left it there.

You are saying it runns better with the spout in?

His 91 should have forged pistons like my 90 does.

Yeah, the pistons are forged.

I had a little bit of time to mess with it today and I put my computer back in the car, pulled the spout, and set the timing to about 20* this time. It finally runs about like it should. I may have had a little pinging right before it shifted but it may also have been an exhaust leak. Whatever it was it was very lite. Regardless, I've about decided that either something is wrong with the chip itself or something is wrong on my EEC where the chip attaches.

So for now I am just going to run it like this until I can get the chip back to my tuner to be checked out or reburned. I just wish I knew where my A/F ratio was running without the chip and the spout pulled. Have any of you who run your cars like this ever checked your A/F on the dyno? Do they usually run pretty rich?

Thanks again for all the help, Ryan

It's not your EEC, it adds timming and that's what usually causes pinging (excessive timming). You will probably need to get some sort of timming control (MSD) and that should fix up your issue. If you are getting a bit of pinging with the spout out, back off your timming, you should be ok with 18-19 deg. I have the same type combo as you (TW heads, 9.3:1 comp, e cam, etc..) and the most I can get is roughly 19 deg with 10 PSI of boost.

Just something for thought.

What is your quench distance? This affects detonation.
Your cam is not stock yet you do you have stock injector timing?
With that cam i'll bet your injectors are firing way too late.


Ive seen properly set up engines with 11.0:1 static compress run pump gas with aggressive timing with no detonation.

It could be a combo of these two things that give you detonation so easilly. Just something to think about.

Quote:

---

Originally Posted by NothinButNotch

So for now I am just going to run it like this until I can get the chip back to my tuner to be checked out or reburned. I just wish I knew where my A/F ratio was running without the chip and the spout pulled. Have any of you who run your cars like this ever checked your A/F on the dyno? Do they usually run pretty rich?

Thanks again for all the help, Ryan

---

Sounds like it's too much timing in the chip. Do you have a S/C calibrated meter? 42's i'm guessing? They run really rich like this. mine was 11.0 all the way across and 10.8 from 5800-6250 on my old 302 setup. No chip, 8* initial timing(spout in), and 38psi fuel pressure. No pinging ever. And yes this was with a novi 1000 and 8" crank pulley.

Well I talked with my buddy at the shop where I got the blower, the chip, and the tune and it turns out they had a batch of 3 chips they recently got in that he just found out 2 were bad. You might guess who has the third chip of that batch?!!! So I hope to have time to go by there tomorrow and reburn another chip to see if that works. So at this point we dont know for sure but he said he wouldnt doubt if something was wrong with the chip I have. Damn chip cost me to waste a week of my life!!!!!!!!!!!!!!

With that said I am just glad something isnt internally wrong with the motor (except all the damn holes I probably have in the top of my pistons now from all trial runs with detonation). But I drove the car to work today and was so glad just to be able to get on the gas and not have it ping. It obviously doesnt idle like it will with the chip or have great part throttle response but that will hopefully all be fixed soon.

I will post up when I find out for sure if the chip is the issue and how the car runs after we get a chip with a good A/F ratio and timing in the car. Thanks again for all your help guys, Ryan

Anytime, glad to be of help.