back to the drawing board- still not running right

**pajeff02** · 08-28-2009, 04:42 PM

Popping out the exhaust generally means it is either lean or you have a timing issue. Low fuel pressure would result in a lean condition. I can steal a pressure gauge if you need me to.

**97bluebird** · 08-28-2009, 08:19 PM

Could also be an intake vacuum leak. Try a new throttle position sensor. I would really lean toward it being a leaky intake gasket though.

**Zapper2003** · 08-29-2009, 03:43 AM

It only pops when i let off the throttle. I will go to autozone this a.m. and see if they sell/rent a fuel pressure gauge. I know on their website they sell one for like 50+$. I'd rather borrow than buy one at this point.

**Zapper2003** · 08-29-2009, 07:17 AM

I just went to autozone and those mouth breathing fucktards don't know ohms from voltage. I was going to have them test the MAP sensor, but now that i've read their 'how to' i know how to do it myself once I get it back on the car. Its quite carboned up around the port, and the gasket is probably fine to reuse. I tried spraying brake clean around the intake but i didnt figure out anything doing so. It started idling really rough after startup (before i sprayed) and smelling very rich again.

**Zapper2003** · 08-29-2009, 10:40 AM

Okay. SO, i just got home and reinstalled my original MAP sensor and cleaned it with the MAF cleaner as well as the MAF itself. Runs worse than ever, idle is low again (950 range) but its barely running, REALLY REALLY rich. Definite miss/skip/stumble.

I broke out the voltmeter and I have 5.05vdc on the two outside wires of the MAP sensor when the ignition is on and the vehicle not running. I dont know what this means, but thats my result. (i live at approx 1600') and in the cheatsheet they had, 3.5-5.5 was tolerable, but there was also something in there about having 5v on one wire anyways, so fk i dont know. Anyone tell me how to test these things? I cant imagine its the only cause of my horrible running conditions.

Also, I can rent their fuel pressure tester that comes with noid lights (?) for the injectors to test them as well. 140$ deposit but i get that back when i return it. What are the specs for fuel pressure and what exactly is a noid light and what does it do?

**bigrondownhiller** · 08-29-2009, 11:22 AM

I checked my manual. The part you tested on the map sensor is for voltage to the sensor which checks out fine. To do the signal voltage test connect the pos lead to the green wire and neg to the black wire. With the car on not running you should have 4.5-5 volts. Start the engine and let it warm up. The voltage should be 1.5-2 volts at idle. When you raise the rpm the voltage should increase. The noid light is something that plugs in between the injector and harness. It lights up showing that you have voltage to the injector. Do you have a vacuum pump? Might want to rent one too so you can test the fuel pressure regulator. Fuel pressure should be 41-47 psi with the key on engine not running. At idle is should decrease by 3-10 psi. Injector resistance should be 11-14 ohms.

**Zapper2003** · 08-29-2009, 11:46 AM

Well, I have to say it. FFFFFFFFFUUUUUUUUUUUUUUu

I finally got a CEL, but I dont think its gonna help me much

Cylinder 8 misfire.

Cleaned the IAC valve, it was pretty sooty. Restarted the car, it was running rich and stumbling (fouled plug) and idling around 850-1000. However, once the CEL came on it ramped right up to 1500 and stayed there.

**Zapper2003** · 08-29-2009, 12:37 PM

Also, which brand plug should I run? I put ac delcos in last time.

**bigrondownhiller** · 08-29-2009, 12:48 PM

That is what I run. Never have problems with them. When it is dark out you will be able to check for arcing easier when it is running. Then you can see if a wire is burnt.

**Zapper2003** · 08-29-2009, 01:30 PM

I checked this the other night. as i said, its puking some serious black smoke out the exhaust and smelling rich as hell. I am willing to guess at a fouled plug rather than burnt wire, however, I may replace it all again.

**bigrondownhiller** · 08-29-2009, 01:47 PM

If it is running that rich I don't think a fouled plug would be the problem. Pull one or two and check them. If it has been running rich for a while they probably have to be cleaned or changed anyway. Check that fuel pressure.

**Zapper2003** · 08-30-2009, 07:14 AM

Plugs have zero miles on the, just a lot of short cycles (starting, running poorly, shutting off before reaching temperature etc). I don't fuck around with cleaning plugs. They're cheap. I'm going to put new ones in, but what should I use, ACDelcos or NGKs or what?

**JaycenK** · 08-30-2009, 09:47 PM

Don't change them till you figure out what is causing the problems. Your just going to foul them out again. take some 400 grit sand paper to the old plugs and clean them a bit till you find out the problem. If your getting a misfire on 8, I think thats the corner were those intake gaskets failed. If anyone knows for sure please post up some facts about those intake gaskets but from stories owners have told me they had big problems when it rained and water leaked on to that area of the intake and cars stalled out because of it, then ran fine for a while.

**Zapper2003** · 08-31-2009, 03:16 AM

It took me two days to change JUST plug 8 last time I did these fuckin' things, and I didn't even change it cuz my arms are too big to get in there

. I hate pulling these fuckers.

**Zapper2003** · 09-01-2009, 02:35 PM

OKAY. Gonna go pick up my wires in a little bit and start that horrid task tomorrow.

I tested all of my injectors, they all ohm out from 12.3 to 12.5 ohms. I dont know what this means, but they're all in spec.

HOWEVER. I restarted the car and it was idling rediculously fast, 2000rpms or so. I left the code scanner hooked up (Actron from autozone, we own it) and I went into the "I/M Monitors" and was looking at things. The temp outside was about 70ish, and the scanned picked up the IAT charge as 71 degrees. Cool, it works. HOWEVER, the coolant temperature was reading 39-41 degrees F when the temp gauge was coming up just over 160!! Could this be the problem i've been having all along? If im not mistaken, the sensor on the front of the water pump feeds the PCM only, is there another sensor that sends the signal to the dash? Regardless of this, I am going to pick up another sensor and put it in.

**pajeff02** · 09-01-2009, 06:26 PM

Originally Posted by Zapper2003

OKAY. Gonna go pick up my wires in a little bit and start that horrid task tomorrow.

I tested all of my injectors, they all ohm out from 12.3 to 12.5 ohms. I dont know what this means, but they're all in spec.

HOWEVER. I restarted the car and it was idling rediculously fast, 2000rpms or so. I left the code scanner hooked up (Actron from autozone, we own it) and I went into the "I/M Monitors" and was looking at things. The temp outside was about 70ish, and the scanned picked up the IAT charge as 71 degrees. Cool, it works. HOWEVER, the coolant temperature was reading 39-41 degrees F when the temp gauge was coming up just over 160!! Could this be the problem i've been having all along? If im not mistaken, the sensor on the front of the water pump feeds the PCM only, is there another sensor that sends the signal to the dash? Regardless of this, I am going to pick up another sensor and put it in.

If the engine thinks it is cold it will stay in open loop. I believe there is a timer function that if it does not reach a certain temperature within a specified period of time that it should trigger an SES. I had that problem on my DD last year and it ended up being a thermostat that was sticking open.

**Zapper2003** · 09-02-2009, 02:47 PM

Alright, coolant temp sensor changed nothing. Im waiting on the car to cool down before I change plugs, however, I suspect Im wasting time. It should smooth things back out, however, its still idling rediculously fast. Starts out around 1600, but as it warms up, it creeps up to 2100. It seemed to have cleaned itself out a bit, its still idling a hair rough, but its not throwing a misfire code anymore. I'm gonna start with plug 8, that way it just gets better from then on

.

**5.0THIS** · 09-02-2009, 03:33 PM

Just take it to a place with a tech2 scanner. Most shops charge around 100$ for a diag fee... Will probably save you money over just throwing parts at it.

**Zapper2003** · 09-02-2009, 04:33 PM

Getting it to said shop is the hardest part. I could possibly drive it, however, the idling at 2k isn't helping that any, and its not inspected.

**Zapper2003** · 09-02-2009, 04:34 PM

Just changed plug 8, did it pretty easy

I have to wait for the engine to cool back down now. My scanner this time showed the coolant temp at -40. Wtf is up with that thing? I wonder how the hell its getting that figure, unless there is some kind of short or something.