[84supra_n00b]

Hi everyone. I'm new to the forum, and I'm new to Supras, so please excuse me if I display my ignorance.

I have an 84 p-type, which I got for $250. It had a blown head gasket, and 175k miles. I have since fixed the head gasket, and I've been driving it with little/no issues for the past few weeks. Recently, and suddenly, it has started sputtering and losing power when I put it under acceleration. For example, if I accelerate away from a stop sign, it will shake, sputter, and act like it's got a severe timing issue or misfire, until it gets to about 2000 RPM, at which point it takes off (regains power), and smooths out. I thought it was a timing issue, but timing checks out good at 10Deg BTDC. I checked the compression, and it's all within acceptable limits. The car's got new plugs/wires, clean injectors, new distributor/cap/rotor. The wierd thing is, it only performs like this once it gets hot. I have checked the O2 sensor also, and it seems OK.

I am at a loss what to do...:32: any input would be greatly appreciated. I need this car to commute to college. Thanks in advance!

 

[jsn_ayers]

Change spark plugs. I have had many new plugs go bad after only 50miles on them. Of course they were cheap autolites.
Next would be the fuel pump to change. Both will cause stumble when hot.

 

[84supra_n00b]

Thanks for the quick reply. Yeah, normally I would agree with you, but they're NGK iridium's and I've already tried swapping them for new ones. And it very well might be the fuel pump/filter. I had forgotten to check those. I will do so soon.

OK, so I think I've got the problem fixed. It was a weird solution, but it seemed to work. I've been running a coil/igniter assy from an 86 Cressida that I found at a local junkyard because I thought mine was broken (turned out it wasn't, it was a different problem, solved now). I just tried removing the Cressy coil/ign, and replacing my original coil/ign, and voila! it seems fixed. I still have a bit of a sputter when I floor it from a stop sign, not sure what that could be, but I'm content to drive it as is for a while. Weird how a coil/ign could make such a big difference.... I never would have thought of that.

 

[DreadyDiggs]

NVM, took to long to finally save my post.

Get it 100% and have a nice day

 

[Donn29]

Check your cam timing, just because the ign timing is at 10 doesn't mean the cams are where they are supposed to be.

 

[jzar]

I think you are right to suspect the fuel pump. I would check it if only to eliminate it from the list.

 

[84supra_n00b]

Well, folks, my excitement was premature. It seems that the coil/igniter did not fix the problem for good.... the sputtering is back. It sounds like an awful misfire, and it's now happening no matter if it's hot or cold. I guess the timing belt could have slipped, I will check that tonight. It's weird, though, because if I shove it in neutral and rev it up, it's not nearly as rough. It seems to be worse under load. Please keep the ideas coming...
Oh, BTW, I know it's not bad plugs because I swapped them out with more new ones and it still does it.

 

[paul12]

Checking for a vacuum leak might not be a bad idea.. Also, check to make sure the EGR valve isn't stuck.. that thing can definitely cause some very similar problems!

 

[84supra_n00b]

EGR valve is in good shape (had to replace it to pass smog a few weeks ago). Vacuum leak isn't out of the question, but I just replaced all the bad vacuum lines, and it was running fine till last week. I'm going to check my plug wires (good shape, but used).

 

[Rockheadjc]

I'd check all the spark plug wires for spark leaks/tight connections. You could have a spark leaking out arcing to the motor.
My two cents...

-Rocky

 

[punkray]

I just had the same problem with my supra... it'd start just fine but start running like crap after a few minutes and sputtering and losing power on acceleration until it eventually stalled... it was the fuel pump. Pretty cheap fix considering how rough the car was running.

 

[punkray]

Just read the rest of your posts... yeah, it's the fuel pump, mine started off not too bad but then would barely even start after 3-4 days... it was really noticeable going up hills and all that... AKA under load... anyways, save yourself some time and research and just replace it. That's my 2 cents worth. haha

 

[84supra_n00b]

OK, plugs/wires all good, no vacuum leak that I can find. I'm going to replace the fuel pump and filter. Any recommendations on where to buy one? eBay?

 

[punkray]

I just got mine from O'reilly auto parts... I think it was roughly 150 for the pump and filter... didn't wanna hafta wait for shipping and all that since they had one there and ready to go. I'm sure you could find one cheaper somewhere else though if you don't mind the shipping time.

 

[paul12]

OK, plugs/wires all good, no vacuum leak that I can find. I'm going to replace the fuel pump and filter. Any recommendations on where to buy one? eBay?

http://rabidchimp.com/mkiii-supra-87-92/fuel-delivery/walbro-fuel-pump-in-tank.html

Or you could look at RockAuto.. beware - eBay sells alot of cheap ripoff garbage.

 

[84supra_n00b]

OK, thanks. I think I'll look for a Walbro on eBay.

 

[84supra_n00b]

What do you guys think of this one? Is TRE Performance any good?

 

[paul12]

What do you guys think of this one? Is TRE Performance any good?

Personally, I wouldn't.. Even Walbros on Ebay are setting off the ripoff alarms. A $60 fuel pump might fix your problems.. but not for long.. :ugh:

 

[84supra_n00b]

Well.... alright. I'll check my local NAPA parts house.

 

[paul12]

Well.... alright. I'll check my local NAPA parts house.

:thumbsup: It will probably be worth getting a filter there anyways.