budda

I've posted this over at the turbo mopar forums and have had pretty much no luck. I figure, there's like 14000 automotive geniuses here. Even though you all work on hondas some one might be of some help.

I recently changed the head gasket and upgraded to a garrett turbo in my 91 2.5L spirit. This problem started right before the swap as it being hard to start, and no increase of power at boost.

This is how the car deteriorated after putting it back together.

Day 1 afternoon.
Relatively easy to start. The car ran fine. Idled fine, and drove fine. There was still no increase of power in boost at all. I could hear the turbo spool but there's no increase of power, but as soon as I would put the car in reverse and try to back up the car would stall.

Day 1 evening/night, Still relatively easy to start, but kinda worse. The car shows signs of TPS failure. I could give the car up to half throttle and it would drive, but anything over that it cuts out. It got progressively worse until i had to idle the car home. The car would rev fine though in neutral

Day 2. changed the TPS sensor. It helped a little, but the car still ran wrong.
Later Day 2 put the stock TPS sensor back on. The problems from before were still present, although the car won't rev in gear.

Day 3. Changed the map sensor to an autozone one. The connector had to be cut a little for it to fit. For some reason the map sensor had the wrong plug prongs. Car would barely start and run. Would not rev or anything. Same deal with the stock computer.

Then tried putting in the 2 bar map sensor from my 87 lebaron. Took out the stage 3 computer and put the stock computer back in. No change.

Later i got an advance auto parts map sensor. This one also had the wrong prongs. It ran decent actually, but with the stage 3 computer, the car would run REALLY rich at idle, and as soon as it hit boost, it went super lean.

Tried the same map sensor with the stock computer. This is the best the car ran yet. Ran very rich due to the +20 injectors, but ran good. Ran strong at boost, but hit overboost cut out at 4 psi.

Returned that map sensor and changed it with another advance auto parts map sensor that had the proper plug prong configuration. This one ran worse, and hit overboost at 0 psi. This was clearly a tbi sensor. I returned it and put the stocker back on. The car was extremely difficult to start through all of this.

later i changed the coolant temp sensor. No change at all. The car would still take about 40 seconds of cranking to start.

I checked the grounds and alot of them were missing. I replaced them all and the car now starts a hell of a lot easier but it continues to have the same problems, although slightly better.

I have checked voltage at the sensors. They came up correct. I have never gotten a fault code.

Bullet points.

- Car pulls 20 in hg of vacuum at idle.
- The car runs brilliantly at idle.
- Sputters a little now when i try to rev it, but it revs.
- I have to give it over 3/4 throttle to keep the car from dying when i back up. Then it shows no sign of weakness. Any less than that it dies immediately.
- after moving the car, when it reverts to idle, it dies, come back, idles fine for a second, dies, comes back. I had the same symptoms in my ranger. It was the MAF sensor. So i have no idea what it is here.

In gear
-idle - fine
-1/4 throttle - bucks like crazy
-1/3 throttle - shuts off
-1/2 throttle - shuts off
-3/4 throttle - still shuts off
-WOT - sputters and accelerates.

Whatever's wrong with the car, it continues to get worse.


Furthermore, I've gotten NO fault codes, no check engine light. The fuel filter and pump are new. I've replaced the grounds. This is clearly an electrical issue but there's nothing to indicate anything at all wrong with this car.

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necessaryevil

sounds like the thing is running lean as soon as the boost starts to kick in, with the bigger turbo you need to remap your fuel curves to match, get your self a air/fuel gauge and find out for sure. but im going to guess that your computer need reprograming for more fuel- hope this helps

reikoshea

thats just creepy. the above is right. you definitely need to get a remapped computer, but i dont think that's the real issue. my gut tells me you were close with the thought on the map sensors.

if you have an ohm meter id test that map and make sure its giving accurate readings

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B

day 1 sounds like a vacuum issue.
day 2 sounds like a spark issue
day 3 sounds like the wrong fuel map on the computer


After playing with the map sensor and getting better results, i'm poitning to a vacuum leak. You're over boosting/cut at 0psi, which means the wastegate vac line or line to the computer or something is getting the wrong reading.


Get some bubbles and get the hoses wet. the one that makes a bubble is the one with your leak.

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necessaryevil

depending on much of a boost differance between to new turbo and the old on you shouldnt need to change the map sensor(1.0 bar good up to 10lbs of boost, 2 bar good for 20lbs)but when you do you need to reprogram the computer, same as when you upgrade injectors. but im almost wondering if the map sensor wires are switched around since you had to cut some of the connector, run the vin number though the dealer to see what was stock in the car couse the connectors should be different between the '87 and the '91, but i would return the sensors and injectors back to the ones that came off, rig the wastegate open, and double check the ground connections, and try that out, if it runs better then add things piece by piece and leave the turbo for last since you need to get that ecu reprogramed, keep us posted

78civic

Ever get this sorted out??

E

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Calesta

Check your plugs? Just a hunch. I think you're not igniting- either because your mixture is off from sensors being screwy, your mapping being off, or just not enough spark. I had this exact same thing happen on my Civic way back- went through and replaced a TON of stuff.. turns out it was just a spark plug with a missing tip. Crazy.

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