I just installed a new fuel pump and now it seems my 1985 iroc tpi is running rich. There is no check engine light on and I scanned it for codes and there is none. Any suggestions on what could be the problem?

 

I just had the same problem, remember if the previous fuel pump was not working properly then it wouldn't be pumping the amount of fuel it should - low psi, therefore it would be running leaner.

Once you put the new pump in, it pumps as it should - higher psi, which means your car would run richer.

 

It really smells rich out the exhaust. I think I have another problem.

 

Try popping the injectors out and soaking em in lacquer thinner for a day or 2. Replace the O-rings.

 

get a wideband air/fuel gauge an quit guessing if it's rich or not . it should be 14.7 at idle an cruise an 12.5 at wot . if it's turbo's it should be 11.4 at wot .

 

Could you explain procedure to the test with a wide band fuel/air tester? Can one be rented/borrowed at Autozone?

 

Basically, you spend $300, in order to discover that you need to pop the injectors off and soak them in lacquer thinner overnight.

There's a time and a place for "troubleshooting" with test eqpt and tuning aids and instruments and such.... this ain't it. Repair before tune.

Best to try the simple, obvious, and cheeeeeeeep, before worrying about things like that.

AFAIK, no.

 

i disagree with sofakingdom a wideband is a great tool to have even when the car is running right . because then theres no guess work as to what your a/f ratio is . i won't build a car without one .

 

I agree......wideband is one of the best tools to know how your car is running. It removes the guess work as stated above.

Now that I have one.....I cant' go back.

 

Yes a wideband is a wonderful tool to have. I'm not disagreeing with that idea.

However, it is not NECESSARY to buy one to work on THIS PARTICULAR problem. Buying $300 worth of test eqpt, to tell you that you need to spend $2 on some solvent and some elbowgrease, when you ALREADY KNOW you need the solvent and the elbowgrease in the first place, is not a wise use of funds.

 

I agree......it's a great tuning tool, it doesn't solve his problem. No argument there.

 

i agree it 's not the fix for this but it takes the guess work out of it . it agervates me when people want to build a car an then guess at the important things when theres tools to use to take the guess work out of it . n as far as the price , if 300 for a good gauge is to much then you need a new hobbie or a part time job , YOU GOTTA PAY TO PLAY !

 

D00d, he needs to CLEAN HIS INJECTORS (or at least, somehow make sure he has clean ones) BEFORE spending $300 on a tool that tells him he needs to clean his injectors.

There's a time and a place for instruments of that sort. FIrst and foremost, TUNING an engine that has been MODIFIED. The time and place ARE NOT when REPAIRING a stock motor with an otherwise simple, easily diagnosed, readily recognizable, common problem. No expensive instruments are necesary to tell him that. Kind of like, if I look at a crank and see deep gouges and the surface turned blue, I don't have to go out and buy a micrometer to tell me the crank is fornicated. Same principle here.

 

an if he cleans them an it's still not running right then what ? actually the ebl flash would also come in handing so he could see his tps an everything eles . you all can guess away at problems i have all these tools for mine i'm just trying help the man out . these cars run rich from the factory people claim there rich but is it normal rich or more an without a wideband your just poking an hoping ...

 

You just really don't *GET IT*, do you??

No these cars DO NOT "run rich from the factory". Wherever you got that hallucination from, send it back. Believe it or don't, The Factory was legally obligated to submit them to all manner of emissions testing and certification, THE WHOLE POINT of which is, to make SURE they ..... EMIT ..... as little unspent fuel products as possible. IF ANYTHING, they run LEAN, in stock trim.

But, I digress.

Sure, EBL Flash would be wonderful... so now you're up to what, $500 or something worth of TUNING TOOLS you're telling the poor guy he just HAS TO go out and buy, just to FIX a STOCK system?

At that point, it'd be cheeeeeeeper to just go to the stealership and just BUY all-new injectors, put em in, and BE DONE WITH IT.

However, it's MUCH cheeeeeeeeeeeeper still, if his existing stock ones are farkled and beyond mere cleaning, to just buy a set of used Mousetank ones off ebay for like $35. Maybe even throw in a super-expensive fuel pressure regulator too, for like $15; and basically replace his entire fuel system. FOR A TINY FRACTION of the cost, especially considering that after he's gone out and bought all that other stuff AND FIGURED OUT HOW TO USE IT, he's gonna have to then go out and buy THE PARTS HE REALLY NEEDS, ANYWAY. Keep in mind: HE'S REPAIRING A BROKEN STOCK SYSTEM,, not modifying or tuning ANYTHING. Which is why it makes more sense to stick with attacking the problem head-on as cheeeeeeeeply as possible. He simply DOESN'T NEED all that other stuff for the task at hand, regardless of how "nice" it would be to have it.

 

i get what your saying it's cheaper to just poke an hope . i get it . i can't wait to hear what the problem really is .lol an your wrong these cars run rich from the factoery . how do i know you may wonder . simple i have a wideband so i know this for a fact .lmfao . you sir need to stop all the arguing an thinking you know it all an have a more open mind to the subject . get off the buget train . i get yor point . i'm doing bebating with you .

ps if his injecters were clogged he would be running lean .lmfao

 

the the op if it is really running rich you couklld put a fuel pressure regulater on with a gauge an dial it back . if it's rich at idle but not in the higher rpm's you can get one with a vacum refference so it will idel leaner an as the vacum goes away unfer throttle the pressure rises to meet the more fuel demand . i'm sure some ashat is gonna wanna argue this also but ask around i'm right on this fix ....
and this is were a wideband comes into play so you know how much you need to turn down to get your a/f right . someone earlier said you wasn't tuning but infact if you need to adjust your fuel intake then you are tuning an these tools help .with the right a/f you save gas and thats a big plus right now . if the injecters where dirty they would be clooged an running lean

 

Sometimes; they could also be sticky or have chunks of crud keeping them from seating.

Stock FPRs have a "vacuum reference". They already perform exactly as you described (when not broken of course...). No need to "ask around" on that.

 

ol really i gues they forgot to put the vacum line hook up on mine . get the **** outta here , your really looking stupied now .lol

 

He's correct, coarse with his answers a lot but correct in this case.
TPIs have a vac hose on the fuel psi regulator, I don't think TBIs do..

 

Hey, at least I know how a fuel injection system works (unlike YOU obviously), and I know how to spell.

TBI's FPR is vacuum-referenced too... has to be, same as any other EFI system, and NOT because of "to meet the more fuel demand"... you just can't see the vacuum hookup because it's inside the TB casting.

And, I know how to FIX a BROKEN CAR, with a minimal cash outlay on UNNECESSARY stuff. Just like, I can do a brake job without a lift, for example, even though I'd really like to have a lift, and it'd be really nice to have a lift, and I could do really lots of cool things with a lift, and no doubt "if I can't afford a lift I have no business working on my car"; but for a brake job, I finf that a jack and a stand are entirely adequate.

 

Guys, Sofa's right. Feeling a tab grumpy, apparently, but he's right. TPI regulator is vacuum referenced, just like almost all port fuel injected engines of that era (including TPI). It keeps a constant differental of 43 PSI between the injector and intake manifold, regardless of the manifold vacuum level. That's it's purpose.

Now, that being said, have you verified that the fuel pressure is, in fact, ~43 PSI at the fuel line schrader valve with the vacuum line OFF the regulator? It should be. If it's abnormally high, that can be your rich condition right there.

Also, I'd beg borrow or steal a scan tool (which you can do at some auto parts places) and see what the computer is saying about things. In particular, look at the Block Learn Modifiers after you've been driving for a while. They should be near 128 (middle of the range). If they're dipping down close to 110 (bottom of the range) the ECM is trying to lean the mixture to compensate for a rich condition (like, perhaps, leaky injectors).

And another thing.... when was the last time you put a fresh O2 sensor in the car? Or did a basic ignition tune-up with plugs, wires, cap and rotor? Check the ignition timing?

What I'm saying is that putting a new fuel pump in the car in all likelyhood didn't cause the problem. It just uncovered an unrelated problem elsewhere in the system once you had adequate fuel delivery.

 

One last thing.... forget using your nose to determine whether things are rich or lean. Unless you have wisps of black smoke coming out the tailpipe to visually corroborate a rich condition I would never suggest trying to tune by smell. If the cat is gutted or removed you DEFINITELY can't trust your nose.

If it was actually running dead-rich the ECM should eventually throw a code indicating it. Yours isn't so I'm instantly suspect of a quick "it smells rich" diagnosis.

 

no where does it say he has a tpi ...

 

no a tbi doesn't have a vacum reference if it was then they wouldn't sell special ones that are . lmfao i really am done with you ...

 

Really? So... not only can you not spell, and don't know how EFI works either, but you also can't even READ?

How about THE VERY FIRST SENTENCE of his post?

Eh???

To take money from idiots like you that have never actually looked at one and don't have a clue how they really work. Obviously you've never even READ the "ultimate TBI mod" pages around here that tell how to take the FPR off the back side of your TB and put a coin in it to bump the FP up. Go do that, maybe visit the TBI board while you're at it and learn a little bit about what you've got.

PLEASE if you're "done", go away, and quit demonstrating that you have nothing that can actually HELP this guy, and all you're interested in is ... well, I'm not sure what .... but whatever it is, it isn't of any value to anyone here. Bye! I'd say it's been nice talking with you, but... I'm not a liar.

 

i never said tbi didn't have a fpr it's just not vacum referenced . an one more thing **** YOU ! your a typical troll who just wants to argue . go back to playing your video games an shut the **** up !

 

What's all this talk about TBI? I believe he said it was an 85 TPI engine.

So, come on, let's play nice. It's stuff like this that chases people away from the board.

I stand by my recommendations, above. If he's got access to a wide-band, then great- use it. But this is a stock motor here. I would hang up my skates if I couldn't diagnose and fix this issue without resorting to one. There's already plety of technology on the car to help with diagnosis, including a perfectly adequate narrow band O2 and an ECM that will tell you what it's reading if you get a basic scan tool and use it.

 

Really... quite enough already. It has long since quit being informative or fun. Besides, I thought you told us you were "done". ??

I hope the OP didn't get scared off by all the nastiness.

 

youshouldn't have started the **** ...

 

Just a FYI; all the cuss words are really not helping the OP, us or you in any way shape or form. Better knock it off or the mods will.

 

sorry if i offended yoou or anyone else

 

Apology accepted.

 

so instead of argiing over how to see the problems lets talk about a way to fix this mans problem .