ive had a rich condition for some time now and a bad stumble at idle car shakes and exhaust smells like gas. i polished and cleaned intake 1 month ago and its now thick with black soot and smells like gas the intake too smells of gas. ive changed my cts(although the one in my passenger side head is dissconected because it melted, would this cause a prob?) checked timing checked tps and i pulled my injectors yesterday and they dont seem to be leaking. i changed o2 about 1 yr ago but who knows if its good what could be causing this , i need realistic things ive had to change plugs 4 times in the past year cause they run like crap beig covered in black. please someone ideas. i need to get my car painted but i want to figure this out first thankyou.

 

Can you check out the BLMs or anything else? Is there a vaccuum leak? Could it be an oil leak. MAT sensor?

 

I'd say 02; mine had all those symptoms and it was 02. But sounds like you changed yours... Do you have a buddy with a known good one that you can test?

 

Sounds like the same problem I'm having. I think I've narrowed it down to the O2 sensor too, but I've yet to fit the new one to confirm that. My car isn't so bad when you just start it up, but after 5 minutes it gets real doggy and rich. My O2 sensor is about a year and a half old, but that doesn't mean it's ok. It's a $26 part, so it's not too expensive.

 

im going to change o2 but what would an oil leak do to cause it to run rich? and also does the mat usually go out? thats the one on the underside of the plenum right? thanks guys

 

By CTS you mean the one in the front of the intake manifold yes?

 

Another posibility is that you have a bad injector or two. The ohms readings should be above say 12 ohms. Anything below is marginal or just plain bad. An injector with low ohms such as 3 ohms will be dumping fuel and cause a rich condition. So measure your injectors with a VOM. Allen

 

How and when do you measure the injectors?

Thanks,

Chris

 

Pull the electrical connectors from the injectors and put an ohm meter over the contacts. That's all there is to it.

 

Contacts at the injectors I presume? Also, reading is in Ohms and what should be the "effective" range?

Thanks alot,

Chris :hail:

 

Yes, there are 2 pins on the injector. When I checked mine they were all around the same-just over 16 ohms. I've posted my own results. That's my injectors ruled out...unless there's one that's dirty or sticking, but I'm almost positive it's the O2 sensor, just to get tthe time to swap it out.


1. 16.3
2. 16.3
3. 16.4
4. 16.3
5. 16.3
6. 16.2
7. 16.2
8. 16.3

 

Thanks RMK. Now to get the time to do it.....

Chris

 

No problem. Let us know your findings and if you get the problem solved.

 

I had this and it was a faulty ECU.

My brother had this and it was a faulty temp sensor (car thought is was freezing).

 

Hang on a sec....

WHen you say you polished the intake and now it's black, you don't mean the outside visible part do you? If you're getting carbon on the outside of the intake then you have a big vacuum leak somewhere, possible on the intake gasket itself. And a vacuum leak will cause all sorts of driveability problems from running rich like you described.....

You might want to get some spray carb cleaner (or brake cleaner works for this as well) and spray it around tghe gasket and mating surfaces on the top of the engine. If you hear the rpms raise up or hear the engine change while spraying somewhere then that's where a vacuum leak is. Unfortunately it can also be on the under side where you can't spray and test it, as well.

Just my two cents worth.....

 

With TPI I think the very first thing you should check when running overly rich is engine vaccum. I think that every TPI should come with it's own vacuum guage. lol.

Find a buddy with one, or buy one. Slap it on. I bet you have low vacuum since you just put it back together and all of a sudden this started.

If its the O2 sensor, I'd be surprised that it just 'went out' at the same/similar time you did the other work.

HTH....

 

I was going to suggest major vacuum leak as well.

 

I don't see how a vacuum leak would lead to a rich condition (ie smelling gas). In fact, I'd say it would lead to a lean condition. The engine would be getting more air than it thinks -----> Lean, at least until it goes closed loop at which point it can adjust for it via the O2 readings. Regardless, you shouldn't be smelling gas due to a vacuum leak.

Speaking of which, does it happen in open loop, closed loop, or both?

BTW, mine used to do this because of an exhaust leak near the O2 sensor, which corrupted it's readings.

 

check ur vaccum could have warped or cracked ur runners if u f-ed w/ em. check ur gaskets. and definitely check ur o2 sensor. Though definately check the o2, w/ tpi u can eat spark plugs in about 2 miles of driving

 

I had to read through that twice before I understood it. TPI does not "eat" spark plugs. Any other engine can do anything a TPI does to spark plugs. If you are eating spark plugs your problem is definatly not the induction, rather another big problem.

 

Dudtin Mustangs,

My car does runs rich and boggy when it heats up, but is fine when it's cold. I'm going to try the CTS then failing that swap over the ECM.

 

well i checked my injectors and one is at 6 ohms and another is at 13.3 so i assume this is what is causing my rich problem correct? i also bought a new o2 sensor but am not putting it on untill i buy new injectors. the inside of my plenum is black by the way and smells of gas. and i sprayed for intake leaks but didnt use vaccum guage so...ill try to change the injectors and see what happens but first i need to buy a paint job(coming this week) so ill let u know how things work out... thanks

 

Hi
One thing no one has suggested is to check your wiring.
My 82 TPI bird has been running rich for a year till last week.
Back in Feb I converted to an Heated O2 to get the car to pass emissions. No codes were set, but it still ran rich.

I think I had a bad ECM for the past year. My 82 bird set in a body shop for almost one year. There was welding going on etc. So I think the ECM was damaged.

A few weeks ago after driving the car back home, the car refused to start. The ECM was fried, refused to pulse the injectors. I change out the ECM. I then found an bad Coil and change that too. I finally got the car start.

After replacing the ECM, it set code 13 indicating a bad O2 sensor. I went though and check the wiring and found a open ground sense to the O2 sensor. After repairing the open circuit, the engine is no longer running rich.

The moral of the story is, Check That Wiring!

 

The MAP sensor or the vacuum line from it to the plenum can cause a very rich condition. I moved my MAP sensor to the firewall to make room for my fuel pressure gauge and it would fuel foul the plugs in less than five minutes. I had done a lot of other mods to the engine when I did this, so it was not easy to diagnose. I could not figure out what I had messed up to cause it to run so rich, I had installed 24# SVO injectors so I thought this was the problem. What caused it was the longer and loose fitting vacuum line I had put on the MAP sensor to reach it in it's new location. You probably did not move your MAP sensor, but you may want to check the vacuum line or the sensor may be bad..





One of the MAP concerns is how it's tied to the engine.
The size, type, and lenght of line all matters.
3' of 1/4" line is alot different then bolting the sensor to the manifold, like they did on some of the v 6's.

 

Double post

 

i have an 89 tpi 350 i dont think it has a map sensor right?

 

alright I am in this same boat right now after my swap from tbi to tpi. I reused the same vaccum hose from the tbi setup for the MAP sensor. if this is what is causing my rich problem, how do you fix that. can't change the way it is hooked up so prom wise what can be changed?

 

Yes, an 89 TPI should have the MAP sensor. On my 90, it is on the back passenger side of the plenum. It is that black piece in my pic with the green connection on it and the small vac hose coming off of it going to the plenum. I went through about ten oil changes and a few sets of plugs before I stumbled across that post one nite. The statement under the pic is a quote from Grumpy. When I read that I knew that was my problem, that little vacuum hose is kinda stiff and smaller at one end. The piece I tried to use was long to reach the firewall and did not fit tight at the smaller end, I guess it sends bad info to the computer. I fabbed up a bracket so that I could put it back where it belonged without interfering with my fuel pressure gauge.

 

You can see the MAP sensor beside the fuel pressure gauge in this pic.

 

Aren't MAP sensors only used on SD cars? The TPI equipment I got from an '89 was MAF based so perhaps not all '89 cars had MAP sensors?

 

hey guys.. try and figure this one out.. it has me an Dyno Don stumped.

my car runs way rich when cold.. in fact it wont hold idle at all. now when it gets to 130* it idles fine..

we experimented a little bit, and check this out... we took another temp sensor(the one that is screwed into the manifold) heated it in water.. then connected it to the harness while the car was actually cold.. car starts fine.. and doesnt run rich when it is warm.

now we plug back in a cold sensor.. it dies..


the weird thing is, if we give it more air, like unpluging the vacuum to the canister, it will idle.. probable cause it needs more air to burn the fuel..

im using LS1 injectors from SLP,supposed to be rated @ 25#.

i have no yet tested those.. and don already recalibrated the ECM for the large injector..

we just cant figure out why it acts this way when cold.. its definately heat related.. anyone want to through out ideas?? please?

 

You're right , no map on an '89 TPI

 

Sorry, I thought SD started in 89.:shrug: