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Timing is getting retarded, running out of things to try

G

grand99

New member
I have a 1999 grand prix with a freshly rebuilt motor in it. It was running perfect for about 2000 miles, but out of no where it started to bog down when accelerating (usually happens under light acceleration). Also, when the car is started cold the revs bounce up and down between 600 and 1400 rpm for about 15 seconds (its been doing that since the very first time it was started after the rebuild), but idles fine after that. The car runs fine once up to speed, and the bogging down problem is intermittent but getting worse. The car is not stock, it has a K&N CAI, HV3 inserts, custom tuned pcm, msd ignition coils, gt1 cam, 90# springs, and Borla mufflers. We have had the car to three different shops now and one shop ran a smoke test and they found an intake manifold leak, but the other two ran the same test and didn't find anything. We do know the car is throwing code P1133 and that the knock sensors are telling the engine to retard the timing. The car also makes a ticking noise when cold, but the sound goes away once the engine is warmed up, the shops all said this sound was because of the cam. So far the upstream oxygen sensor has been replaced twice along with the MAP sensor, TPS, plugs and wires, knock sensors, PCV valve, and the MAF sensor has been cleaned. I have spent a lot of time trying to track down this problem and I'm out of ideas so any advice or ideas would be greatly appreciated. Thank you
 


i pretty much stopped reading at freshly re built motor. who re built it? a shop? or you did in your garage? if not a shop, find a new used engine, dont ever touch the bottom and and carry on.
 
It was rebuilt by a shop, it is under a 3 year warranty. Do you think something internally is causing the problem?
 
could be. these engines dont like to be rebuilt unless all the machine shop work is done right. if they are local, let them look at it.

warranties do rule.

scanning for KR at all? when kr is detected the pcm pulls timing, so it will be lower when it sees KR. (knock retard.) if you are seeing kr thats for sure whats up.

every degree of kr takes a degree of timing out as ive been told.

so if your set at 15 for timing, and see 5 degrees of kr, your timing will get pulled down to 10 degrees.
 
Ya I've been scanning the KR and it has retarded the timing as much as 20 degrees.

The shop that did the rebuild has looked at it and they keep blaming it on everything other then their own work. I think they know they screwed something up and they just don't want to deal with it.
 


Scotty you think his MSD coils might cause problems or would it probably be misfiring if it was, just something that caught my eye when reading through his mod list.

Also OP whats the p1133 code, it might be relevant to the issue.

In relation to the bogging does the car have a cat on it? If so it might be plugged but I would think that would set a CEL. Also what brand of 02 did you use.

Sent from the Milky Way
 
The tune was done by ZZperformance, and one of the shops mentioned the coils might be throwing it off but it wasn't misfiring so I didn't think anything of it.

Ginseng can you be more specific what you mean by by running to rich in the 7000 hz table? Does that have to do with the tune?
 
grand99 said:
The tune was done by ZZperformance, and one of the shops mentioned the coils might be throwing it off but it wasn't misfiring so I didn't think anything of it.

Ginseng can you be more specific what you mean by by running to rich in the 7000 hz table? Does that have to do with the tune?
Click to expand...

exactly, zzp is known for **** tunes. If you have anyone in your area i would have someone look at it.
 


I know iceman is near grand rapids I think, and if he is I think he does tunes. Might be worth it too PM him see what he has to offer for a tune.

Sent from the Milky Way
 
zzp, yeah great stuff. you need to find a local to scan it for you with a tuner program and maybe fix it up some.


grand rapids is MI right? should be able to find some one close by.
 
Ya Grand Rapids MI, I'll look into finding someone around here who can do that. I didn't have much choice other then to have zzp tune it at the time. Anyone know of any tuning shops here that they would recommend?
 


P1133 is a o2 switching code, not a heater circut code. Has zero affect on anything, o2 sensor will continue to work like any other normal o2 would.

And get some stock coils.
 
I would not say this code has zero affect on anything, it could possibly lead you to the root of your problem. Actually the P1133 code means that the voltage fluctuations after the motor has gone into closed-loop is not switching, or not switching fast enough. O2 sensor voltage should constantly be changing from somewhere under 500 mv to somewhere above 500 mv. This could possibly be due to a very lean or very rich fuel mixture, bad o2 sensor, too high fuel pressure, etc, etc. Read the o2 sensor voltage while the car is running - that can indicate too lean or too rich.
 
BUT, that test is only ran once per drive cycle. So during the one time 60-100 second test period it didnt switch the say (guessing here) 50 times and only did it 48, and it set the light off. But 3 minutes later while not testing it switched over 60 times in the same time period. It's a pretty common issue with modded exhaust and placement of the front o2 sensor. The sensor still works like normal and can read like normal but sometimes it can just be a tad slow.

I've had brand new denso sensors read these codes and over time they just went away.
 
Fivefingerdeathpunch said:
BUT, that test is only ran once per drive cycle. So during the one time 60-100 second test period it didnt switch the say (guessing here) 50 times and only did it 48, and it set the light off. But 3 minutes later while not testing it switched over 60 times in the same time period. It's a pretty common issue with modded exhaust and placement of the front o2 sensor. The sensor still works like normal and can read like normal but sometimes it can just be a tad slow.

I've had brand new denso sensors read these codes and over time they just went away.
Click to expand...

I agree with what you say here, but I would still check the function of the closed-loop O2 sensor system. A quick peek with the scanner should tell you if the mixture is ok, or if you're running way lean, or way rich.
 
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