tbi error codes, engine missing, help please

[mikayak390]

Ok so as usual my 89 burban and I are having a minor disagreement. This week its error code 32, and 43 both are intermittent. But when the engine is at normal temperature and worked hard or put into overdrive I get a missing bucking engine. Plus the idiot lights just for show.

So engine is only a year old. Same with trans. When they work they are great. I know its something stupid. Changed the EGR valve and vacume lines for the second time this year, gave it another set of plugs and wires last week(I was supprised to find my #1 plug wire died after only a year that cylinder must have been out a while to based on the plug.

The map sensor is only a year old but just for fun I swapped a working one in last week. Even gave it a new ignition coil just to help with a weak spark. I have checked the timming several times with the advance wire pulled its fine.

So what is the electronic spark control that my little book suggests is bad?

I have replaced the ignition control module in the distributor twice as well. (again no reason just seemed like a good idea at the time)

So short version.. $80 a tank every 4 days, the body is starting to rust, I need at min 2 new tires, a set of springs and its running like hell. I love my truck but Chevy, ford and Jeep all have some interesting sales going on.

Before we end up with a parts for sale add, any thoughts on what my truck is unhappy with at the moment?

Oh btw. yes the problem gets much worse if I have car adds in the cab, or stop and talk to dealers. Seriously its fine some days, but if I go into a dealer lot its going to run bad by the time I get back on the Highway.

Someone please help before its to late. I have been considering a Ford ranger just because its cheap and good on gas. That is just an insult to my suburban. But unless things get better with me and the burban we may have a breakdown followed by a break up.

Thanks for your suggestions.

 

[chevyjeff]

I think code 43 is for the knock sensor failure, when the ecm does its knock test and doesnt get the knock sensor to read a knock it faults, throws code 43 and retards the timing way back until you turn off the engine and restart. next time it acts up turn it off and restart and see if it runs better.

 

[mikayak390]

Well it clears the engine code and runs better for a while, but a few minutes later it will be back. I have gotten very good at going to neutral while driving and just bumping the ignition key off and on with out engaging the starter.

So where and what is a knock sensor? I'll google it later, but tell me again how much better tbi is than a carborator...

Thanks again for the suggestion!!

 

[Iron_Weasel]

CODE 32 - EGR SYSTEM:

The ECM operates a solenoid to control the Exhaust Gas Recirculation (EGR) valve. This solenoid is normally closed. By providing a ground path, the ECM energizes the solenoid which then allows vacuum to pass to the EGR valve.

The ECM monitors EGR effectiveness by de-energizing the EGR control solenoid thereby shutting off vacuum to the EGR valve diaphragm. With the EGR valve closed, fuel integrator counts will be greater than they were during normal EGR operation. If the change is not within the calibrated window, a Code 32 will be set.

The ECM will check EGR operation when:

* Vehicle speed is above 50 mph.
* Engine vacuum is between 40 and 51 kPa.
* No change in throttle position while test is being run.

CODE 43 - ELECTRONIC SPARK CONTROL CIRCUIT:

Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM drops, and this signals the ECM to retard timing. The ECM will retard the timing when knock is detected and rpm is above about 900 rpm.

Code 43 means the ECM has been low voltage at CKT 485 terminal "B7" for longer than 5 seconds with the engine running or the system has failed the functional check.

This system performs a functional check once per start-up to check the ESC system. To perform this test, the ECM will advance the spark when coolant is above 95~C and at a high load condition (near W.O.T.). The ECM then checks the signal at "B7" to see if a knock is detected. The functional check is performed once per start-up and if knock is detected when coolant is below 95~C (194~F), the test has passed and the functional check will not be run. If the functional check fails, the "Service Engine Soon" light will remain "ON" until ignition is turned "OFF" or until a knock signal is detected.



BTW, I can get you diagnostic diagrams if you need them.

 

[4xcrazy]

Just because it's throwing codes, doesn't really mean those are your problems, mine did this same type of thing a few years back, kept throwing all sorts of codes at different times, changed out everything the code was related to, but even after that it would still throw it again,,,

I finally found out, in my situation, that the fuel pump was going out, had very weak pressure, would idle ok, but when you get on it, it would buck, stutter, back fire, almost die, whatever. I was out in California when it got real bad and finally got tired of working on it, so i drove it home to Phoenix, and it really never hit O.D. because it was running so bad.

Anyways, check your fuel pressure, it just sounds too much like what i went through,,P.I.T.A.

 

[BigBurban350]

I had that problem too with the same codes. My EGR was removed and I had a lot of problems with the spark codes.

When the engine was in my burban here are the specs. 390 stroker (4.060x3.75), 305 heads, performer intake, 350 TBI w/ 454 injectors, full length headers. I never figured out what was going on because I had that setup when I was going to college, therefore I couldn't afford s***.

Now I am a lot more educated with TBI's and this is what you should do.

Goto this website

Build the cable or hes got links to places that sell them pre-made. Ebay has the cables to sometimes. If you can solder, you can build this cable super cheap (under $10).

Then obtain a laptop and install the software, plug and play. Remember in the setup of the winaldl software you will need to select your PCM, I am pretty sure 100% of TBI trucks use the 7747 PCM.

Once you're in the engine computer, you can log data and watch knock counts, watch your fueling, check error codes, and pretty much all the electronic engine parameters.

If you have more questions PLEASE visit/join Thirdgen.org and go into the DIY PROM or TBI forums. There are a lot of stickies or just post up a question. It is a car site, but the computers are no different (7747 and 8746 PCMs are 99.5% the same only have one difference).

 

[mikayak390]

Thank you again for all the information.

 

[jimmy'sjimmy]

i have been having almost the exact same problems with my Jimmy. Changed the EGR and made it idle a little better then the truck just decided to die and not even run. I went through everything i could think of and replaced all the plugs and wires and coil. Still wouldnt run, when i found no fuel pressure i figured it was a bad pump but when i started to drop the tank i noticed it was way too light! It was empty! yeah the truck needs gas to run anyway it ran, but ran very poor missing and struggled to get over 45mph. took it back to the shop and went over the ignition again, figured i messed something up, when i noticed the ESC hangin next to header, it was unplugged. Plugged it in and she runs purty again.
Long story short make sure you have all the simple stuff out of the way first or u could look like me

 

[txfiremank5]

I got those same codes when I bought my 89 K5 last year. Upon inspection, I found the knock sensor plug to be damaged. I replaced it and cleared the comp. After a while I got a code 32 again, but the 43 was gone. As of yet I have done nothing about the 32. It hardly ever comes on, but still does from time to time. I keep thinking I need to track it down and kill it.. for good.