More Problems....

[vetteboy86]

Well, some of you might know I had a lean exhaust code about a month or so ago. I replaced the fuel filter, and the O2 sensor, and also added a bottle of chevron techron to the fuel, to clean the injectors.

I unplugged the ECM to clear the codes, and then checked to see if they were still in memory before I started the car, and they were not.

Okay, fast forward about 3 weeks, and 600 miles. The car has run great, no problems, idle was good, performance was great, and no engine light. I am gettting great gas mileage.

Today on my wat to school, the SES light came on. Suprised the heck out of me. The car ran okay, then it went off. It cycled several times before I reached the parking lot at school.

I leave school, and the car ran like crap. It actually stalled twice. At idle it would idle down, and then fall to about 400 RPM's then back to 800 RPMs, and keep doing this until it died. I checked the code from the computer and it is code 44 (Lean Exhaust) again. How the heck can this be. I drove it home after eating at the gf's, and the car ran okay. I put it in the garage and let it idle for about 5 minutes, no light, but idle searched really bad, but never stalled.

I have some scan stuff coming that should be here next week. I just dont know how the same problem can reappear after so long. Any suggestions?

 

[MoeJr]

My guess is under certain conditions the stock prom is not liking the mods on your engine. May have to try and get the custom prom done to get rid of the problem. Just my .02.

 

[vetteboy86]

It was cooler today then normal. I wonder if this contributed to the problem. Just seems odd that the same lean exhaust came back.

 

[Vettelt193]

sounds like a sensor is giving a bad read...

Also: Did you check the fuel pressure?

When you left school, did the car run good until it got warm, or like crap right away?

 

[vetteboy86]

It seems to run better when the ECM is controlling the fuel curve. Seems like as soon as the engine starts reading the O2 sensor things start going crazy. The car seemed to run good for the last 500 miles. Could the O2 have fouled out again?

 

[vetteboy86]

sounds like a sensor is giving a bad read...

Also: Did you check the fuel pressure?

When you left school, did the car run good until it got warm, or like crap right away?

Yeah, I had my brother help me check it. The pressure was 55lbs with the vacuum line unhooked, and 47 with it hooked up. I am told that some people with stroker motors usually run about 43 to 45 lbs of pressure with the vacuum line unhooked. I am wondering if the car is running rich, and fouling out the O2 hence I am not getting a good reading? I am not sure, I do know that if you stand behind it for about a minute your eyes will start to burn a little. I do have some black build up on the inside of the exhaust tips that is fresh, and seem sto accumulate as I drive. I can wipe it off with my finger, and then it will cover over again after driving.

 

[Hrtbeat1]

Sounds rich to me. That scanner should be there in a couple of days. Follow the instructions and we'll getrdone.

Also check around for any possible vaccuum leak. They play havoc with idle.

 

[vetteboy86]

Well, get this, I went to check the fuel pressure today again. My brother popped the cover off the scharder vavle, and we heard no pressure release or anything. So we hooked the guage up, unplugged the vacuum line to the AFPR, and gas started shooting out where the vacuum line goes. So now WTF. Why would gas come out where the vacuum line goes. My brother says his does not do this. With vacuum there pulling on the diaphram, it isn't good for gas to be coming out. Maybe I dont understand what is happening.

Any Help.

 

[rrubel]

Well, you shouldn't hear pressure release from the schrader valve unless you're pushing the valve stem, which will result in gas shooting out.

As for gas from the vac fitting, it sounds like the diaphragm in your FPR is leaking. Have you pulled it recently or something? Was that one of the parts that the mechanic touched?
[RICHR]

 

[vetteboy86]

It was brand new, when I put it on the car. Well yes that is a good thing, because the valve is like that on a tire, you have to push the pintle to get air out. However I am totally at a loss with the fuel coming out from where the vacuum plugs into the AFPR. I really wanted the adjustable one on there for tuning. I guess I can try to take it off, and see what is going on.

See it didn't do that the first time I checked it.

 

[Hrtbeat1]

Like Rich said it sounds like the rubber gasket part of the diaphram is shot. Thats the only way I know of for fuel to get to the vaccuum tube of the FPR. That may explain why your computer was saying lean but all other signs said rich.

If you replace it with an aftermarket go with the Holley one the AFPR comes with a new daiphram.

 

[vetteboy86]

I already have the holley one, it was on the car for about 800 miles, and the diaphram is bad. Now I called summit, and they said to replace it with a stock diaphram which I know will not work.

So does anybody know if I can buy a replacement for the Holley??? If I cannot, then I will not put that back on, it would be nice to be able to replace the diaphram and not the whole assembly.

 

[vetteboy86]

Well I am a little ****ed off about this whole situation. I just got the car back, and something stupid like this happens. I tried to call Holley, and was on hold for ten minutes, so I said screw it. I have sent two emails to them, one yesterday, and another today. If I do not here anything from a member, or the company, I am just going to buy a different brand, one that will have a replacement for these types of things. The deadline is noon tomorrow.

Thanks,
Craig

 

[milehigreg]

Craig. Wish I could help but I'm just not knowledgable in this area. Might I suggest you take a few days off from the problem and clear your mind a little. When you do get it figured out, and you will!, take a road trip out here to Colorado and I'll give you a hug and buy you a beer.

 

[vetteboy86]

Well hopefully the fix is in the mail and should be here today, or tomorrow. As soon as the new AFPR goes on the car, I am going to drive it often. I have some tuning software that I am going to get some readings with. So hopefully by friday evening all will be well again.

 

[Vettelt193]

I had this problem on my '93. much worse though really. The FPR was so shot that it fed gas into the plenum, then down into the cylinders. Talk about a real PITA to deal with.

 

[vetteboy86]

Well it sure was feeding gas back into the plenum and down into the cylinders. That is probably why I had some issues with the car running. When I pulled the plenum, I had a good gas smell. I have pulled the plenum before without noticing this. I dont think anything was hurt, just made the car run bad. It is fairly an easy replacement, the new crane cams is supposed to be here today, but I am still waiting to here from holley. I guess which ever one looks and functions better is what I will go with.