Car wont go over 3500 rpm !!

[Cornflakes_GLHT]

ok cool... thanks for the ideas .... BUT

I did unhook the downpipe and started the car ... standing still and bringing up the engine to 3000 - 3250 rpm and it did the same thing.

ALSO : I installed an ajustable FPR and +40% injectors and it does the same thing !! i ajusted the pressure up to 50 lbs (gauge installed on rail) with the +40% and it did the same thing at the SAME EXACT rpm .. wich is 3250 (first bar after the 3k mark on the tach) ...

I also remove the valve cover to check if anything was out of line .... everything is perfect .... im running out of ideas !!

at this point. here is wath i checked :
everything that has to do with spark/ignition (installed everything from the Omni that works fine)
AFPR and +40% injectors (from the Omni)
replaced MAP
bypassed baro (vacuum in MAP instead of going through baro then MAP)
checked wires from the computer to the grounds and sensors (resistance in the wires and voltage to and from computer)
checked basic timing and cam/valve timing
unhooked exhaust (in case of a blocked cat/exhaust)
checked vacuum lines everywhere
checked purge solenoid and canister (thing in the right front fender)
replaced fuel filter
I also have a scanner that plugs in the diagnostics port (behind battery) and checked every sensor with it (rinding in the car and standing still) - every reading is just fine


An other note : I can drive the car if i dont go over 3100 rpm. and I would doubt my vane solenoid because when driving i get normal boost ... i mean if i floor it i will get my 12psi but wont go over 3100 rpm and if i let it climb the rpms slowly not in the boost it will do the same thing ....

Since this is now in the VNT forum and its not really a VNT issues .... does anyone have a SPARE VNT COMPUTER ?? I would like to see if something is up with mine ... but i cant find one here !! i will pay shipping if anyone has one i can borrow and if it fixed the problem i would probably buy it !

thanks a lot for the help guys !!

Pascal Labelle
90 VNT daytona
86 GLHT Turbo II

[Shel-Game]

Quote:

Originally Posted by Cornflakes_GLHT thanks for the ideas but the TPS is fine, i have a ODB2 scanner and i can check all the sensors .. and TPS works fine. i will check cam timing just to make sure i didnt skip a tooth. ill get back to you guys with this .... too weird !!

What volts do you read on your TPS at 0 and full throttle? Just because it's working doesn't mean it's not in error. If it is higher than 4.7V or lower than 0.16V, then the TPS fault will trigger and the rev limiter will set at 3020rpm. It won't set a fault code, though, until it has been above or below the error volts for 50 key-on cycles.

[Cornflakes_GLHT]

I did check the TPS and if i remember correctly, at 0 the voltage was 0.35 and at full throttle it was a 3.75 (ill double check tonite and get back to u)

Quote:

Originally Posted by Shel-Game What volts do you read on your TPS at 0 and full throttle? Just because it's working doesn't mean it's not in error. If it is higher than 4.7V or lower than 0.16V, then the TPS fault will trigger and the rev limiter will set at 3020rpm. It won't set a fault code, though, until it has been above or below the error volts for 50 key-on cycles.

[DirectConnection]

Quote:

Originally Posted by Cornflakes_GLHT ok cool... thanks for the ideas .... BUT An other note : I can drive the car if i dont go over 3100 rpm. and I would doubt my vane solenoid because when driving i get normal boost ... i mean if i floor it i will get my 12psi but wont go over 3100 rpm and if i let it climb the rpms slowly not in the boost it will do the same thing .... Since this is now in the VNT forum and its not reallyPascal Labelle 90 VNT daytona 86 GLHT Turbo II

Check the vane actuator! It's a simple, quick and easy thing to do.
As I mentioned, you don't won't have a problem making boost at all, it will chug like it running on 3 cylinders and make boost in nuetral.

[csxvnt257]

I see in one post that you installed larger injectors and an FPR. I may have missed it, but I did not see in any post that you have reprogrammed your SBEC for larger injectors and adjustable FPR.

Go back to your original config as by installing those two items, you are only complicating your troubleshooting. Do one thing at a time, don't throw multiple parts and changes at it. Start with checking every vacuum line again very carefully. Vacuum is critical for these cars to run right.

[Cornflakes_GLHT]

Quote:

Originally Posted by csxvnt257 I see in one post that you installed larger injectors and an FPR. I may have missed it, but I did not see in any post that you have reprogrammed your SBEC for larger injectors and adjustable FPR. Go back to your original config as by installing those two items, you are only complicating your troubleshooting. Do one thing at a time, don't throw multiple parts and changes at it. Start with checking every vacuum line again very carefully. Vacuum is critical for these cars to run right.

ok ... i must of forgot to mention a few details ....

everything i tried so far i have but back to original config : exameple: i tried a new map, same problem, so i installed my original one back. im not just changing parts around for fun. I do take it one step at a time... but like i said, ive tried a lot of things, but the car allways comes back to the original configuration ... right now i still have the AFPR and the +40`s and that is only to try to get it richer since the plugs are WHITE !!

and i will try the actuator test tonight.

thanks for the input again .. this is very appreciated.

[crazyace]

Put your fuel pressure gauge on it and go for a drive. Make sure the pressure does not fall off under accelleration. One key thing to remember is that even though things appear fine according to the scanner does not mean they are. Chrysler vehciles are some that sub in info when a part fails, if you need proof try disconnecting you O2 sensor and see it center out the volts. I have noticed that with some of the chrysler computers they tend to read correct data though. You just have to be careful what info you believe and do not believe. If nothing else double check it with a volt/ohm meter.

[Cornflakes_GLHT]

Quote:

Originally Posted by crazyace Put your fuel pressure gauge on it and go for a drive. Make sure the pressure does not fall off under accelleration. One key thing to remember is that even though things appear fine according to the scanner does not mean they are. Chrysler vehciles are some that sub in info when a part fails, if you need proof try disconnecting you O2 sensor and see it center out the volts. I have noticed that with some of the chrysler computers they tend to read correct data though. You just have to be careful what info you believe and do not believe. If nothing else double check it with a volt/ohm meter.

yes i did try that. the scanner indicates that the o2 voltage centers out to .50 when disconnected.
also, the fuel pressure doesnt drop under acceleration. it goes up by about 5 pounds or so and stabilizes when comming to a stop.

[Cornflakes_GLHT]

Quote:

Originally Posted by DirectConnection Barry, I had a bad vane actuator on my VNT that wasn't functioning properly. It was doing as you described.... keeping the vanes shut. But, my plugs were BLACK from being rich. It wasn't able to burn off the fuel due to poor scavenging. After having the car idling for sometime trying to diagnose what's wrong, the car would eventually foul out the plug entirely. I would have to buy new plugs and squirt oil in the bores to bring up enough compression to run again. This car would not rev over 3k and would also build boost in nuetral. Ran like it was on 3 cylinders the whole time. I swapped it out for another used one and even now, I occasionally have to pop the hood on my car and give it a little nudge. After that it is fine. Do as Barry suggests and feel the actuator rod when someone starts the car up. Be real careful as the back of the intake may slam your arm against the firewall if not enough room when starting. One of my VNT Shadows has room, the other doesn't.

i checked that just now. since the car was hot, i looked at it. when the car started the little arm moved down a bit ... not by much, but it moved.
ill wait until tomorrow morning and ill check if i can move it by hand, and then start the car.

ill keep you posted.

[90VNTDaytona]

same thing happened awhile back to me on my vnt. timing belt was off 1 tooth on the cam. found out lots of people mess up the cam gear timing on the 2.2s because they think it should be straight up and down, when in fact when the motor is in the car its angled back slighty so if you just put the dot to the top it makes it off one tooth (if you follow what i saying). even the first time i looked at it i thought it was right, until nothing else fixed it and i rechecked cam timing and it was indeed off. worth a shot to check it again, cause like i said, i had the same exact problem and that was the cause.

[boxcar]

If you're checking the cam timing using the hole in the upper belt cover and a timing light make sure you set the light at 0* if it's a dial-back light or turn your distributor to 0* adv. if you have a non-adjustable light. You want the light to trigger at exactly TDC and if you look in there with the light triggering at 12* BTC your cam will appear retarded. If the oblong sprocket hole is at the front or back edge of the hole in the cover you're a tooth off. You want it dead center.

[Cornflakes_GLHT]

yeah ... cam gear timing is fine.... i use the whole at the top of the gear and also the left and right arrows on the gear to align it

I also did the actuator test on the turbo this morning .... when the engine starts the actuator moves down and when i throttle it a bit it will move .... so that seems fine.

im gonna run more tests tonight after work ... but ill check in here a couple of times in case some one gets a crazy idea !

thanks

Pascal

[Dan Culkin]

All of the symptoms you describe (the lean plugs, the 3500RPM issue, the fuel correction percent) are symptoms of the cam timing being one tooth off. Specifically, the cam is rotated clockwise one tooth more than it should be.

It may be worth your while to "dummy check" the cam timing - mark the belt and the cam gear, slide it off, and slide it back on with teh cam gear rotated one tooth counter clockwise (hole toward the back of the car).

[Cornflakes_GLHT]

ok .. news on this

cam timing is fine ... tried 1 tooth foward and 1 back and its the same ... so timing is ok. can smelled bad when off back or fourth ...

wich brings up to my next question ... anyone has a vnt computer i can try ?? ive tested so many things and still come up with nothing ... its the only thing i cant test .... ill post in the for sales/want to buy sections.

[ShelbyGLHS592]

Do yourself a favor and swap in another TPS. The VERY same thing happened with my cousin's GLHS. We tried everything. The TPS never showed up as being bad until we swapped another one in.