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Wont Rev with full throttle


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So Ive been working on my 92 SPFI Loyale for a few weeks now. Ive got all of the oil leaks fixed(for now) and its running pretty well. However if I floor it quickly as if to pass someone or accelerate onto a highway it will stumble until I let up on the throttle, then it will accelerate again. If it downshifts

(3at) it will fall on its face, until I lift slightly and then it will accelerate correctly.

I can get it to do it in neutral also. Sitting in neutral vehicle stopped I can put my foot to the floor and the engine will rev until 5200rpm and then fall back to 3500rpm...back to 5200 and then 3500 over and over just like a rev limiter. If I smoothly put my foot almost to the floor (about 90%) it will rev to over 6000rpm.

Things that I have tried are....

-cleaned the MAF with Maf cleaner.

-cleaned Idle Air Controller.

-Set timing to 20 degrees BTDC

-Set Throttle Position Sensor as per a thread on this forum(cant remember who started it at this time)

-Removed TPS, opened and cleaned with contact cleaner. Also used a multimeter to check for proper resistance and continuity. Everything checked correctly.

My old Subaru knowledge is kinda lacking and I have used the USMB as much as I can however Im starting to get irritated at this thing now.

Another issue which may or may not be a big deal is Im having a hard time getting the idle to operate correctly. Ive tried setting it up as per a thread on "setting idle" but it will idle correctly while cold but when its up to operating temp it will idle really low, about the first mark on the tach, 500rpm. If I disconnect the IAC most of the time it make no differance on operation. Just today is the first time I have been able to get the idle to drop with the IAC disconnected, and it only effects it occasionally.

Sorry for the really long post but Ive tried searching and trying about everything that I believe could cause a similar problem.

Thanks in advance,

Jonathan

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Yes I have checked for faults, it has 34 and 35. One is for EVAP purge, cant remember the other and cant find the link to the codes, I have it in favorites on my work computer. My canister purge line is broken and I have a bolt in the vacuum line. It happened during the headgasket repair I did to it a couple weeks ago.

I should also add I just passed emissions with flying colors. And even though Im only on my second tank of fuel, I got 25 mpg on my previous tank.

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D-Check is not the same as checking for stored codes. You need to run the whole procedure.

 

It is possible that the 34 and 35 are not allowing the ECU to finish it's self-test procedures. You MUST fix all codes then RETEST as some may not show up if others are active.

 

Till you fix the existing codes, and start running proper D-Check procedures you will be entirely frustrated, and basically chasing your tail.

 

GD

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I can get it to do it in neutral also. Sitting in neutral vehicle stopped I can put my foot to the floor and the engine will rev until 5200rpm and then fall back to 3500rpm...back to 5200 and then 3500 over and over just like a rev limiter. If I smoothly put my foot almost to the floor (about 90%) it will rev to over 6000rpm.

Jonathan

 

Sounds like the 1st cat could be partially plugged.Put a vaccuum gauge on the intake for a painless quick check.

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Screw cars Im going fishing tomorrow:banana: ...anyways Ill work on this thing on Sunday. I was actually busy today at work so I didnt really get a chance to tinker with my Subaru.

Ill try to dig up a vacuum gauge. What readings do you guys have for a healthy running EA82 (please tell me there is such a animal)

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Normal idle vacuum will be something in the 15-20 inch range.

However,in this case you are more interested in the reading at the 5200 max rpm point.

 

If the cat was plugged,I would expect a low reading that drops to a minimium at 5200 relatively slowly.Exact #s are hard to predict,but,probably something like 6-0 inches.I`ve actually seen 2 psi positive pressure in the intake of a car w/a severely plugged cat that wouldn`t rev beyond 2500.

 

May not be your problem,but,it is worth a quick check.

You can get an idea about normal readings by putting the gauge on another car(as long as it doesn`t have a lumpy cam).

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I'm going to say.... replace the TPS again.

 

Did you look at the TPS board, notice any scratches or anything where the "feet" on the knob meet the board? My old one was adjusted correctly, cleaned the best I could, and reinstalled... My car did the same thing.

 

I got one from a JY, untouched, threw it in, car did fine.

 

And I never got a CEL, nor did I ever get anything in D-Check.

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I'm going to say.... replace the TPS again.

 

Did you look at the TPS board, notice any scratches or anything where the "feet" on the knob meet the board? My old one was adjusted correctly, cleaned the best I could, and reinstalled... My car did the same thing.

 

I got one from a JY, untouched, threw it in, car did fine.

 

And I never got a CEL, nor did I ever get anything in D-Check.

 

I didnt notice any scratches, but it is really hard to see the entire path that the feet travel.

Im going to try the vacuum gauge tomorrow at work, and then try the D-check. And then perhaps borrow a known good TPS from another car...ie take one from beataru.

Thanks guys, Ill report my findings.

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