Will not rev past 4500

[FreeCandy]

I just bought a 1989 voyager turbo automatic and am very excited. Transmission shifts smoothly and just fine under normal load, but at WOT (when the tranny downshifts itself to stay in a lower gear) it never shifts because it is not reaching its shift point. It just bogs at 4500 rpm, almost like hitting a fuel cut.

Help me please, I just bought this thing and have done everything I could think of that might carry over from my knowledge of SR20DET 240sx's, but I know next to nothing about this particular vehicle. The boost solenoid is not attached, it has a grainger valve placed between the wastegate and the compressor housing, no vacuum leaks, and I'm about out of ideas. Bad trans sensor somewhere? IDK, help me out please.

[BadAssPerformance]

Welcome to the forum!

I'm not too familiar with automatics... Might be an issue with the kickdown cable setting?

[FreeCandy]

Hmmm, I'm not used to messing with the old autotragics either. Thanks for the idea, I really need to figure this out so I can stop putting so many miles on my SR

[Juggy]

how many PSI r u running????

[FreeCandy]

6 psi

[Juggy]

turn the key back n forward 3 times. the check engine light will flash. with slight pauses in between

count the # of times it lights up...this will tell us if you are throwing any codes.

it should prolly start off with 12

chekc engine light will FLASH.....pause.....FLASH FLASH......pause......1......then 2..... = 12

see what u get. "55" will be end of code. FLASH x5 with pause, then 5 more flashes


the hall effect pickup can acuse problems when getting into that RPM range as well. wonder if its defective? thats the HEP sensor under the distributor...it has 2 wires coming out of it each with a plug, one black, one grey

[FreeCandy]

the check engine light was off when i got the thing, but it was still doing this 4500 rev limit thing. now its on, but thats bc i took out the boost solenoid i think. i will check the codes regardless and let you know.

as far as the HEP sensor, how could i tell if it was bad? Just pick up a few at the junkyard and try them to see if it stops?

[Aries_Turbo]

cam timing is advanced a tooth or so.

brian

[Juggy]

maybe you unplugged the map sensor, or solenoid by accident?

[FreeCandy]

MAP sensor is on the top center of the firewall with a vacuum line from the intake right? Its all plugged in, could it be bad?

solenoid is no longer even in the car, but that shouldnt matter since its got the grainger valve right? I know it can make you throw a check engine light, but it was doing this even before i took out the solenoid (which is by the charcoal canister, right?)

will check the codes, and the timing. about the timing, i have a light but does anyone know the degree values of the ticks on the crank pulley?

[turbovanman²]

Could be a bad TPS but check codes and go here-

http://www.turbo-mopar.com/forums/vb...e&articleid=30

Timing is 12 deg, with the coolant sensor disconnected-its the sensor behind and to the side of the thermostat.

You can also check cam timing too using the light-

http://www.turbo-mopar.com/forums/vb...&articleid=131


Unless the trans is severely damaged, it won't be causing your issues.

Go to this site, turbo database section and read it a few times-

www.thedodgegarage.com

[pauly_no_van]

+1 what turbovanman says.
Also, some eec's hit overboost cutout at ~7psi.
You description sounds suspiciously like an overboost condition.
You may even have a code stored for it.
With stock turbo you're done at ~4000rpm, at 4500 RPM you aren't making any extra power.
WELCOME!

paul

[FreeCandy]

Thanks again guys, sorry about my absence. I don't have access to the internet on the weekend.

Boost holds steady at 6 psi with absolutely no variation, so I'm not sure how it could be overboost.

I checked the codes and got this:
13 - MAP sensor, vacuum
15 - speed sensor
31 - canister purge solenoid
36 - wastegate control
46 - battery volt sensing
51 - oxygen sensor

I'm not too worried about 31 and 36. I'm almost positive that these are due to the removal of the factory boost solenoid, but there is a grainger valve on there.

46 seems to just be when the alternator or battery puts out at least 1 volt more than 12.6, so I'm not really worried about that either.

13, I'm not so sure about. Could it be a bad MAP sensor? When I got the van, I noticed that one of the 2 vacuum nipples on the MAP sensor was just venting (the other went to the FPR/intake manifold). I just capped it off so that the MAPS would still see vacuum. Could this be part of the issue?

The O2 sensor code bothers me a little bit too. I guess its either bad, or I really am running lean.

Could the speed sensor code have to do with this shifting problem at all? Seems like it might, but I don't know enough about this particular vehicle to say. Help?

Thanks again for all the support, hopefully we can get this figured out soon and move on to bigger and better things.

Also, if anyone could tell me how to clear the codes so that I can see what pops back up, that would be great.

[Aries_Turbo]

disconnect the battery and turn on the headlights for 30 sec. hook the battery back up, start it and shut it off and check the codes.

other than the grainger, hook the vacuum lines up like the diagram under the hood.

check the cam timing.

Brian

[turbovanman²]

Thanks again guys, sorry about my absence. I don't have access to the internet on the weekend.

Boost holds steady at 6 psi with absolutely no variation, so I'm not sure how it could be overboost.

I checked the codes and got this:
13 - MAP sensor, vacuum
15 - speed sensor
31 - canister purge solenoid
36 - wastegate control
46 - battery volt sensing
51 - oxygen sensor



46 seems to just be when the alternator or battery puts out at least 1 volt more than 12.6, so I'm not really worried about that either.

It could still be a bad alternator, it might not be putting out full amperage, you need to check amps.

13, I'm not so sure about. Could it be a bad MAP sensor? When I got the van, I noticed that one of the 2 vacuum nipples on the MAP sensor was just venting (the other went to the FPR/intake manifold). I just capped it off so that the MAPS would still see vacuum. Could this be part of the issue?

Yes, one side goes to the intake, the other to the MAP. Make sure the MAP has full manifold vacuum

The O2 sensor code bothers me a little bit too. I guess its either bad, or I really am running lean. To check it, go here- http://www.turbo-mopar.com/forums/vb...e&articleid=22

Could the speed sensor code have to do with this shifting problem at all? Seems like it might, but I don't know enough about this particular vehicle to say. Help? Transmission has NO electric controls, the only thing this will do is affect the idle speed and could cause it to cut out.

Reply's in red.