I've got an 86 GN with a fresh motor(1100 miles) It's got Kenne Bell cam, Manley valves,port clean-up on the heads,K.Bell 2 1/2 exhaust,stock turbo with 30 lbhr tomco injectors@ 42psi static.I have adjustable FP regulator with walboro pump and a hot wire kit.
I have access to a snap-on scanner at work and it showed me 11 degrees of retard @wot today with lots of pinging I,ve got the stock chip. Any suggestions short of replacing every sensor under the hood. I know verything is right in the motor cause I was very careful when I built it. Help please.
What boost level and octane fuel?
Dean
12-14 PSI and 92-93 Octane fuel,usually Citgo Brand. I forgot to mention that the baering on the belt tensioner is bad,I don't think that would trip the knock sensor @WOT I will have a new one Monday.
I got a quick glance of the o2 @ WOT and it was .898
Any one please??I've read a lot of the threads in this forum and still am stumped.
898 02's and you're getting RICH knock. they should be 800mv max. Increase boost or decrease fuel pressure. Im hoping the belt tensioner isn't changing your timing at the crank pulley allowing it to slip and no longer read accurately. Work out the bugs, but fueling and timing needs to be checked. You should have ~22 degrees timing at WOT on a stock chip. More or less, and there's a problem.
I leaned out fuel pressure to 38 PSI and still 13 degress retard@12 psi of boost.Tryed 34 psi and the same happened. O2 is still too high. My EGR was un plugged,so I hooked it back up and now I can feel a surge at part throttle low speed cruising,highway is okay. Boy have I got some issues..LOL...it idles rough,so I am starting to think injectors. I am going to have them flowed next week to see whats-up. That's cheaper than replacing them.
For what it's worth..i burn my own chips, and using Mobil Premium i could run..29lbs boost with low timing on 93 octane only with a TE44. (!)
Using Citgo by my buddy's house (or $hitgo as I like to say) I couldn't even run 22lbs without knock with NO OTHER CHANGES. Try a better grade of gas. In my experience, Amoco Ultimate and Mobil Premium are the only 2 brands of 93 octane my car will tolerate. Shell, Citgo, Chevron, 66, Speedway...they all suck im my experience.
Is your EGR working? THere is a test for that on this site somewhere, but it may need replacement.
Injectors would have to be stuck open for you to get that rich at 34psi. Put your finger on each one while it's running or hold a board up to one and your ear on the other end and listen for an on/off ticking sound. If one or more isn't ticking, they're most likely bad, or an electrical connection on the harness, etc.
There are some things to work out, yeah - but you'll find it. Does your snap-on scantool log data? Can you post and more information?
Thanks,I'll try different gas. Our scan tool doesn't have the movie function,but all the idle paramiters are within that quick check i found on this site. My injectors are all ticking.
THANKS again I'll keep working I don't give up easy,I love my GN it's awesome.
Check the EGR for proper operation.
Hal,the EGR valve is okay but I am not sure about the solenoid any suggesttions on how to check it?
Ok.. I'm currently troubleshooting knock in my 87 GN as well. As far as the EGR is concerned, once you are under any amount of boost, the EGR is no longer a factor unless it is mechanically stuck open. As far as the solenoid it should never be a factor while under boost since it controls the vacuum to the valve. The EGR should stay closed as long as there is no vacuum. And closed is where you want it at WOT. Someone correct me if i'm wrong because I'm trying to narrow down my sources of part throttle knock (knocks @ 5-10PSI) and i want to get my facts together as well. I changed the EGR valve but wasn't concerned with the solenoid based on that theory, so I hope it's right.
Yes John you are correct,as I said above I was more concerned boutmy part throttle surge that happened as soon as a hooked my EGR back up. It had beed unhooked for the past 5 years for that reason.
My GN only pings @WOT. However it's always had a miss that I can't get ride of,I have built the motor twice(55,000 miles apart)and changed a lot of sensors and no dice.
The EGR still makes the car surge @ cruse. The vavle tested okay,I adjusted the neutral saftey switch. Cts is within spec. Anything else short of replacing the solioid? I up plug it runs good around town until you mat it then spark knocks,Ammoco gas did help though and so did the heated O2. Still working and getting closer.