I've got a 91 Z with TPI 305. So my car has been running really rough lately. It started out just not wanting to start, but performance slowly started to go. I've tested the injectors. They all tested good, maybe even a little too consisant. Every injector tested at 15ohms on the dot. I replaced my Iac. It made little difference. I changed my spark plugs last night, and now the car wont even stay running. If i leave the key in the 'on' position for a minute then start it, it runs beautiful for about 20 seconds then bogs down. It will die unless i keep revving it. I unplugged the TPS and now it runs good, but is wayyy too rich. It makes me think my TPS is bad, but it did run with it plugged in before i changed the plugs. Any help will be much appriciated.

 

I should also add, I changed the cap and rotor from stock to Accell with the plug change. I also replaced the AC DelcoR45TS' with Autolite AP26's. The gap on the new plugs were anywhere from just under 40 all the way up to 50, so i set them all at 40. I am doing a computer reset now to see if that makes any difference.

 

ok some more info...Injectors actuallt test between 16.9 and 17.1 ohms. I replaced the TPS. Old one measured .89volts at idle. the new one .76v. Both of those numbers sound too high to me. the 5v wire measures 5v. I am now getting two codes..22 and 33. 22 is low voltage at TPS or fuel cut-off relay shorted. 33 is high voltage or low vacuum at MAP. Any ideas? PLAESE

 

test your map output. disconnect the vacuum hose and turn the key on should be 5 volt ref on the green wire. pump up your hand pump vac pump for every 5lbs of pressure you will see a one volt drop. hold it a see if there is leakdown. maps are asy to fingd in the junk yard tbi 4 cyl and 6 cyl look for a 466 stamped on the top.

 

Ok, so there was a vacuum leak where the hose from the MAP goes into the intake. It was really loose and fell off. I just put a new hose on. The MAP voltage tested at 4.74v. I don't have a vacuum pump, but sucked on the hose and it dropped steadily. Think that's ok?

 

no sure how accurate your suck test is !!!

 

ok, got that fixed. it's running fairly smooth. I put a timing light on it and it ias jumping from 10* BTDC to 0 with idle surges. Any thoughts on that?

 

HAHA, yeah, probably not too accurate, huh?. Do you think the initial 4.74v is acceptable? And would the MAP throw off my timing at all or make it fluctuate like it is? I did use a slightly smaller vacuum hose on the MAP cuz a hose the same size was still a little loose on the intake side. I just test drove it. It spit and sputtered up a hill, but on flat ground at WOT, it fealt pretty mean. It seems like the timing is going crazy while accelerating. Would there be a reason the computer is telling it to retard and advance timing so much? Do you think resetting the curb idle would help since I adjusted up it before the recent repairs? It is idling a little high now, but I dont understand how that could effect timing. And thanks for the help by the way!

 

is the ecm throwing any codes ?

 

Surprisingly, just 12. I'm adjusting idle now. Oh and what is an ESC? I've been seeing it in threads, but for the life of me, cant figure out what it means.

 

esc is the electronic spark control. you need to disconnect that with the key off engine off a orange wire. start the engine and set base timing. turn the engine off and plug it back in.

 

how many degrees if you dont mind me askin. by ear? or is it TDC?

 

Nvm, I'll just look it up. I feel like I'd feel obligated to pay you if you answered anymore of my dumb questions.

 

I believe it's 6 before tdc look at your emission sticker if it's still there. I use a timing light to set the base on efi ear on carbed

 

rpm?...sorry, i cant find it anywhere on the web and emmisions sticker must be gone.

 

your min idle speed?

 

Yeah, but i'm going with what it is running at. I just set the IAC, so it should be good. Now i just gotta get this clamp loose. Man i've got swivel sockets, hold-down wrenches, anything i should need. I cant get the wrenches in there and i cant get the sockets to stay on once i start turnin em. I don't know how it is staying running though, it's 2*retard without ESC!

 

No distributor wrench... I think the min idle when a/b are jumpered is a amazingly low 400-450 rpm

 

Yeah i have one, but i still couldnt get the angle. Took off the coil and got it with a short open wrench. And yeah, its 450rpm. my car died before it got that low, so i just set it where it died. I think my tach reads high

 

ok, got it. now lets see if i can get it tight again without moving it

 

Oh no, i feel so stupid. I just remembered i have to make sure it is at TDC first, dont I?

 

OK, its runnin great. I think I need to turn my idle up just a hair, but other that, its like new!