Anyone know third gens (TPI)?
03-20-2011, 06:53 AM
#1
Staging Lane
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Anyone know third gens (TPI)? Friend has an 88 trans-turd-AM with a 305 TPI, he was given the car years ago. The car had been sitting for years but had run fine when parked.
When he got it the fuel pump was dead, so we fixed that got the car running and it runs like crap. Also the fan never comes on so it will overheat if you let it run too long (guess just the fan switch). Put a scanner on it and nothing was terribly obvious, it did have some code for MAF burn-off or something, but the MAF frequency seemed to change accordingly to airflow so not sure it's a problem. Coolant temp sensor was working, TPS working fine etc etc.
Checked the basics, fuel pressures good, powerbalance shows all cylinders working equally. Hesitates badly when snapping the throttle, when it's dead cold it's almost impossible to get started without some help with carb cleaner down the throttle body. Idles rough, runs rough, pops out of the exhaust sometimes etc. The other thing is it seems to change randomly, one time it actually ran ok, parked it and started it up months later and ran like crap. Seems to have deteriorated, now it runs just terrible.
This kind of led me to believe a bad ECU or something (maybe leaking caps) so we got a cheap one out of the junkyard and no change. I guess my next suspect is the injectors, maybe the old fuel when it was sitting gunked up the injectors, but still not sure why it ran ok that one time. I guess it could have a bad MAF but seemed to be reading OK when I had the scanner on it. Does anyone in the socal area have a spare MAF we can swap on for kicks?
When he got it the fuel pump was dead, so we fixed that got the car running and it runs like crap. Also the fan never comes on so it will overheat if you let it run too long (guess just the fan switch). Put a scanner on it and nothing was terribly obvious, it did have some code for MAF burn-off or something, but the MAF frequency seemed to change accordingly to airflow so not sure it's a problem. Coolant temp sensor was working, TPS working fine etc etc.
Checked the basics, fuel pressures good, powerbalance shows all cylinders working equally. Hesitates badly when snapping the throttle, when it's dead cold it's almost impossible to get started without some help with carb cleaner down the throttle body. Idles rough, runs rough, pops out of the exhaust sometimes etc. The other thing is it seems to change randomly, one time it actually ran ok, parked it and started it up months later and ran like crap. Seems to have deteriorated, now it runs just terrible.
This kind of led me to believe a bad ECU or something (maybe leaking caps) so we got a cheap one out of the junkyard and no change. I guess my next suspect is the injectors, maybe the old fuel when it was sitting gunked up the injectors, but still not sure why it ran ok that one time. I guess it could have a bad MAF but seemed to be reading OK when I had the scanner on it. Does anyone in the socal area have a spare MAF we can swap on for kicks?
03-20-2011, 11:13 AM
#3
On The Tree
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It might be the injectors that got clogged, or might even be your cap,rotor wire set, my car ran like **** when I had some accel wires and changed to msd and ran better, prob even be the map sensor.
That's the problem with those cars one thing goes wrong about everything will go wrong
That's the problem with those cars one thing goes wrong about everything will go wrong
03-22-2011, 04:22 PM
#7
From what u are saying I see maybe a bad EGR. Test out the EGR, add vaccum to it while the car idles. If it dies or stumbles then the EGR is fine. If it doesn't the EGR is bad. Also if the PCM was bad it wouldn't run. PCM either works or it doesn't. Also what fuel pump did u use? If it isn't factory it can be very possible that it will run like crap. It's happened to me. I bought a holly and about 2 weeks later it ran like crap and pump cried out loud when it was hot and backfired like crazy. Put in an AC Delco pump and it's been running great ever since. 
if u need more help PM me.
if u need more help PM me. Trending Topics
03-22-2011, 07:45 PM
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Staging Lane
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I thought about the EGR, will be testing it next time. It is definitely suspect considering the conditions. I seem to recall doing it before though and finding it was ok. PCMs can be bad and still work, look up leaking caps and bad injector drivers.
Fuel pump is fine, fuel pressure is right where it's supposed to be.
Fuel pump is fine, fuel pressure is right where it's supposed to be.
03-23-2011, 01:46 AM
#11
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im guessing bad fuel filter and/or injectors (stock tpi injectors are known to clog) go to the junk yard and get some stock v8 ford injectors. theyre soo much better then the stock tpi ones.
03-23-2011, 02:09 AM
#15
I know they flow more. I didn't know about the jet spray. But this would make your car run richer. I don't thinks that a good idea unless u are getting a better cam. Stock TPI will run pretty rich. I've had stock injectors in for years without problems. It's just how u take care of them I guess.
