'89 Chevy 'Burban Getting Worse

Chantz · #1 01-01-2007, 03:54 PM

When we first put the Suburban back on the road, the Service Engine Soon light would only come on after about a half hour of highway driving around 100 km/h. Now, all it takes is going from one end of town to the other (maybe about two miles) continuously at about 60 km/h to trip it. Even sometimes when I leave it idling for a while. It's the same codes (32 and 45), but at more frequent intervals. I'm planning on cutting off the catalytic converter, as there's a good chance it's probably bad. Will that help any, or am I going to have to do something with the EGR?

1989 Chevrolet Suburban R1500
TBI w/350 4WD
Automatic 4-speed w/ OD (700R4)

maxwedge · #2 01-01-2007, 04:24 PM

45 indicates the engine is running too rich, high fuel pressure, bad coolant temp sensor ( full scan will check sensor), misfire in the engine, weak vacuum to map sensor also. 32 is an bad egr circuit or operation function, 32 is egr solenoid/vacuum valve inop or bad egr valve.

Chantz · #3 01-01-2007, 06:50 PM

Would it be a safe bet that they could be linked? I mean, if the EGR isn't working properly, it could lead to the engine running rich, could it not? I mean, the engine isn't misfiring because it runs very smoothly, and the coolant temp. reads normally (In the 90-95 degrees Celcius range). I have no idea what kind of pressure I'm getting from the fuel pump, but it was replaced a few years back. How would I check to see if my EGR was bad, or if it was the solenoid/vacuum? As well, I don't really know how to check a MAP sensor either. Any help would be appreciated.

Chantz · #4 01-05-2007, 01:13 PM

Sorry for the double post, but after taking the truck out on the highway yesterday, I got back and there's hissing coming from the EGR. I'm guessing that that would be the solenoid/vacuum problem you were talking about? If so, is that the reason that my engine is running rich, and how hard is it to fix?

maxwedge · #5 01-05-2007, 03:30 PM

Any vacuum loss in the engine will drive it to the rich side, trak this down and fix it.

Chantz · #6 01-05-2007, 06:54 PM

Is it going to hurt it to drive it? Just around town, because I'm gonna have to take it to a mechanic because I can't track down the leak myself. And I'm not sure if any will be open on a Saturday

maxwedge · #7 01-06-2007, 08:34 AM

Not really good the caT COULD BE RUINED, ALSO WATCH FOR FUEL CONTAMINATING THE OIL.

Chantz · #8 01-13-2007, 08:59 PM

I took it to the mechanic and it turns out the base gasket on the carb was toast. It was replaced and the hissing is gone, but I still get the SES light at about 80km/h. Now, the injector (or the gasket, not sure) on the driver side is leaky, but I'm holding off on replacing it as you can only get the gasket from GM and you can only get it in a kit that includes a bunch of gaskets all for the low low price of $50. I need one. But if it's the gasket and I want to test that and it's the injector (another $90), then I need a second gasket because the first one will be wrecked. I'm holding off on it, and so far, no issues with the engine, but is it going to hurt it to run it like that? And is that the source of my Code 32 and 45? Thanks

Blue Bowtie · #9 01-13-2007, 09:52 PM

A leaking injector pod will skew the mixture rich, but probably doesn't have a direct affect on the EGR.

Chantz · #10 01-14-2007, 01:29 PM

Alright. I'll try clearing the codes and then taking it out on the highway again. Could the EGR just be having to engage too much to try and compensate for the rich mixture?

Chantz · #11 01-18-2007, 12:10 PM

So I cleared out the codes and took it out on the highway for a good 10 or 15 minutes at about 100-110 km/h, and I did get the SES light, but when I tried the codes, I'm only getting a 32. The only thing that the mechanic could find was the leaky injector (which I don't want to fix right now for reasons stated above). Is this going to affect the EGR in any way, or is the EGR itself just screwed?

Blue Bowtie · #12 01-20-2007, 09:15 AM

The problem could be the EGR valve pilot itself, the EGR vacuum solenoid, the vacuum supply to the solenoid, or simply clogged EGR passages in the intake (happens frequently). The ECM expects to see a change in MAP when the EGR is activated, and if this does not occur, the code will be set while driving. If the code were to set shortly after starting the engine and not while driving at moderate load/highway speed, it would more likely be an electrical problem with the solenoid circuit. There's a fair bet that the valve and or passages are carboned and clogged.

As for the TB injector pod gaskets, check here:

http://www.lindertech.com/injparts.htm

$6.75 USD

Chantz · #13 01-22-2007, 06:36 PM

Is it relatively easy to take apart the EGR to look for the problem? Or should I get it done by a mechanic? 'cause I did my gas mileage calculation today and I'm getting all of 9MPG or 25L/100km. That's pretty bad

Blue Bowtie · #14 01-24-2007, 03:43 PM

The EGR valve on a TBI engine is rather easy to remove. You may have some trouble with the bolts seizing in the intake, but penetrating oil will help that on the way out, and a coating of antiseize compound will prevent that when teh bolts go back in.

Whatever you do with the EGR valve, don't use any chemical cleaners in the valve pintle area. Your valve should be a positive backpressure type, and any solvents which might make their way to the pilot diaphragm through the bleed hole may destroy the valve. Plain port type EGR valves don't suffer this risk, but positive- and negative-backpressure valves are susceptible to damage.

Chantz · #15 01-26-2007, 01:26 PM

Alright, I might take it apart some time in the near future to see if I can solve that. As for the gasket, if it was just to be installed to see if that was the problem, and it turned out to be the injector itself, and it had to be removed, could it be put back on again? Or would it damage it so that I'd have to have a backup? Thanks for the help!

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