Car bucks and spits rich, stalls only when it warms up
 

Hi - i've been trying to fix this myself for the last couple of days but find that i've run out of knowledge (i'm surprised it took this long...)

the trusty-t (86 T-Type, oem ecu, inj, chip, turbo, maf, 3"dp and dual ex) just started to do this on the way to the boys football games on Saturday. it fired up great, drove down the road fine and then 1/2 way to the field, as i started to drive away from a stop light, it layed down and coughed, i stood on it a little and it picked up to 60k, and cruised fine, then as i got closer to the field, and i had to slow down, it wouldn't accelerate again, just coughing and puking, running really rich, then stalling. i let it cool down a bit and it started and ran like crap, stalling all the way home. i had to bring the mini-van to football...the boys were not happy!!

i changed the ign module and that didn't do anything, i disconnected the battery and that did nothing. i changed FPR's, played with the fuel pressure-still nothing. no bad connections, no vacuum leaks

Help! I've spoiled my boys-they only like to go to football in the Buick!!!

Matt

Do you have a spare MAF you can try?

Plug(s) take a crap? Ignition wire(s)?

I think Sean hit it, check the mAF. Plugs and wires maybe affected by the MAF going bad. Also when doing a module or coil, I recommend doing both as a unit, especially if they are original.

I don't have a spare MAF. i did check the connection on it, but thats about it. i took it out recently and cleaned it out a bit - maybe i damaged something?? i'll call around today and see if i can get one locally. i'll change the plugs while i'm at it, any specifics there i should buy NGK, delco?

thanks!

AC Delco, R43TS plugs...

Thanks!

i called around and in a city of 750,000 people, you'd think i could get a stock MAF? Nope. and the prices were crazy, from $180 to $293 "but the warehouse doesn't have any stock, it'll be a few days plus shipping costs" what a load.

Anyway - does anybody have one or even a Translator set up for sale?

The MAFs aren't made any more, and it's a crap shoot when you buy a reman'd unit. I think that there is an aftermarket company that makes them, but don't know the name or the price. Sorry.
Is there anyone around you that can loan you one just to see if it is the problem?
Do you have a scan tool? If so, what is the MAF reading?

no-don't have a scan-tool. i want to get one but with the upgrading and new tech, i guess i've just never been sure what to get, what i will do is go and get a reading with my multimeter and see what it does.

Ok -i took the old volt meter to it and ign on and the car not running it was moving between 2.56 - 2.65 volts. when i fired it up, it stayed the same. when it revved up, it went to 2.44 and bounced up and back again between 2.4 and 2.6 - nothing changed when it warmed up, but it stalled.

Our MAFs don't output voltage like some of the others, so you can't use a multimeter. They output a wave or pulse or some other kind of electonic voodoo.

Crap. then how do you know what it's doing without the scanner?

There are two ways:
First, you can lightly tap it with a screwdriver while idling. If it stalls, stumbles, or generally doesn't like it, then you have a bad MAF. If not, then it might be good.
Second, you replace with another one.

Sorry, but unless you have a high dollar scope, and know how to use it, then that is it.

Actually, 2 and a half ways. Some people unplug it and see if it idles better, but I don't think that you can accomplish much doing that. Also, that will only help diagnose it if you are having trouble with it running at idle.

One other thing to check: You said that you replaced the ignition module, but did you check/replace the coil pack? I still think it is the MAF, but if you have a coil pack handy, you could rule that out.

Well, i just got ahold of a friend that has a good MAF and i'm going to go and pick it up after work...

Let us know how it runs. Oh, a word of advice. Make sure you don't put it in backwards. I have heard of people doing this, and it just doesn't run right when you do.

Mine did this at one point and it was a bad O2 sensor.

i did the O2 sensor already!! the only other thing that i haven't changed is the cam sensor. if this works than i'll just drive it til the snow comes. Sean has tempted me into getting his MAF-less system as he's going to an XFI system. it's a little complicated (for me anyway) to jump into this late in the year, but it'll be fun for next year - assuming my wife doesn't find out...LOL!!

I hear ya! I did a lot of work to mine this year and I NEED a FAST for all to perform at best but the wife has cut me off the Buick for the time being... but XFI is for sure my next purchase. Hopefully Jack will get a "new" style one here soon for the cheap!!!!!!!!

Wow, are you guys twins??

If you want to rule out the cam sensor, just unplug it once it is running. It will put the car into batch fire mode. That way, the timing of it won't affect anything. I doubt that is it, but it is easy enough to check. Don't forget, you can't start the car with it disconnected, you have to disconnect it while the engine is running.

Sounds like Andys car years back... he had a crank sensor dying sloooowly
we ended up calling AAA on the way home from Etown and dropping it @ Jacks

Good News!
 

i got a MAF from a buddy and i put it in - BINGO! runs actually better than it did before. I have to thank you guys for the help-been awsome!!!!!

Matt

And my wife says I am never right! hahahhaha:D