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Discussion Starter #1
I'll make this quick. My problems are as follows on my '86 eldorado with 4100 engine:

My Engine Control System light goes on intermittently

I can't access the OBD through the driver information center- it doesn't reposnd, whether it's displaying "System Problem", "A/C Refrigerant low", or the usual (incorrect) date, time, temp display.

Sometimes (at random) the car will flood itself out when i attempt to start. I have to take off one of the feul injectors and start it, then replace the jet once it starts running smoothly. It has good and bad streaks: it won't do it at all for a week, then will every time for a few days. This seems to be unrelated to the Engine control systems light.

My gas mileage is very poor: in the area of 8-10 mpg if i'm lucky.

I have codes for TPS and distributer signal fault.

Are all these problems related? Could i need a new ECM? Does anybody have any ideas?
 

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AH... the wonders of the HT4100!!! Gotta love it. I really love those cars style, but the engine SUCKS!!!

Anyway <im not sure, someone else will confirm>, it sounds kind of like a leaking injector...... It must be really bad if you have to undo an injector to get it to start!!!! :shocked: If your gonna do it, you might as well replace all of them...... Also, does the engine seem to do it under a load-idle condition (ie stopped at a stop light with the brake on and in DRIVE)

Regarding the other things, you will need a new TPS.... maybe about $50 or so.... It is a box located on one side of the TB........ I dont know about the distributor code......

You may be able to take it to a dealer and have them read the codes for you.......


Oh and..... Welcome to the forums, and thanks for signing up!!! :)
 

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Thanks for the (very quick) reply. It has no problems at load idle. In fact, when i get the car to run smoothly, it will do so until i shut it off, the only problem being the poor mileage. If it's on the bad streak, it won't matter if i shut the car off for 5 minutes or a day or two. It won't start. Could this still be the injectors?

I looked up the TPS earlier in my haynes manual. I'll check that and see if it's causing problems. I can get codes pulled from work (pep boys) for free, but it involves a little sneaking... ;)

Once again, thanks for your help
 

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The haynes manual is basically useless....... You NEED to get a FSM...... You wont see any cadillac techs with the haynes manual......

The TPS probably isnt causing these problems, although it could be making a bad situation worse..... It shouldnt be too expensive to replace, so Id go ahead and replace it......

What makes me think it is a leaking injector is when you get it running, it doesnt matter if it leaks a little, because it will be burned off in combustion... But when you shut it down, there is still some fuel pressure, and the bad injector will allow fuel to leak into the combustion chamber, and essentially flood the engine........ And it would also explain bad gas mileage.... Excessive leaking of fuel......

When you race the engine (when it is running) under no load (in park), is there any sort of black looking smoke coming from the pipe..... If so, then Ill put money on the injectors........

Have you narrowed it down to a specific cylinder.....
 

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You're doing pretty good Wes. :thumbsup:
Just a couple points of interest;
1. The '86 uses TBI not multi-point so there's only (2) injectors to troubleshoot here.
2. The injectors are quite visible so it's very easy to see if one or both are leaking prior to starting.
3. I'm assuming that you pulled the codes from the ECM at work, are you sure they are current codes and not just old codes left to rot by someone else?
4. The first thing to check is ALL sensor connections (especially coolant temp).

It IS possible that the ECM is bad. Chances are you have a couple issues at the same time that are causing the problem. Shorted injector wires, and/or sensor wires are the biggest chance. The MAP sensor has a tendancy to get fuel-soaked also, especially if it has been relocated or the hose running to it has been improperly routed. With the engine off, follow the hose to the MAP sensor and remove the hose. Is there raw fuel in the hose? if so, replace the MAP sensor.
It's also possible that the ECM has been fouled by coolant. It gets in through the coolant temp harness. I know what you're thinking, HOW THE HELL DOES COOLANT GET INTO A WIRE?
There were many sensors that failed and allowed the pressurized cooling system to basically push coolant into the wires and it just flowed through the wires back to the ECM. This is easily found by opening the ECM and looking at the circuit board at the harness connector. You'll see a green residue if it's gotten in.
Well, this gives you some things to check at least.
 

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Discussion Starter #6
Thanks a lot guys, you've definitely given me enough stuff to check to keep me busy for quite a while. I appreciate your help.

BTW, I am by no means a mechanic, whih is why i only have a haynes. If i could do half the stuff in the FSM, then i would think about getting one. Maybe i will eventually. But for big time problems i like to pay someone else to do it. I'd pay someone to do this, but i have a feeling it would cost more than the car itself
 

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Re: '88 Seville w/ similar problem

You sound like you know what you're talking about. I have an '88 Seville with the 4.5 w/TBI (not much better than the 4.1, but a little). Just starting to have a problem with starting when the car is hot. Usually starts fine when cold. Code says E012 and E053, Distributor signal fault and distributor signal fault (interrupted). I replaced the coil. Checked the Coolant Temp Sensor. Not sure what else to look at. Any ideas? Could it be leaky injectors? Thanks. Pete

Katshot said:
You're doing pretty good Wes. :thumbsup:
Just a couple points of interest;
1. The '86 uses TBI not multi-point so there's only (2) injectors to troubleshoot here.
2. The injectors are quite visible so it's very easy to see if one or both are leaking prior to starting.
3. I'm assuming that you pulled the codes from the ECM at work, are you sure they are current codes and not just old codes left to rot by someone else?
4. The first thing to check is ALL sensor connections (especially coolant temp).

It IS possible that the ECM is bad. Chances are you have a couple issues at the same time that are causing the problem. Shorted injector wires, and/or sensor wires are the biggest chance. The MAP sensor has a tendancy to get fuel-soaked also, especially if it has been relocated or the hose running to it has been improperly routed. With the engine off, follow the hose to the MAP sensor and remove the hose. Is there raw fuel in the hose? if so, replace the MAP sensor.
It's also possible that the ECM has been fouled by coolant. It gets in through the coolant temp harness. I know what you're thinking, HOW THE HELL DOES COOLANT GET INTO A WIRE?
There were many sensors that failed and allowed the pressurized cooling system to basically push coolant into the wires and it just flowed through the wires back to the ECM. This is easily found by opening the ECM and looking at the circuit board at the harness connector. You'll see a green residue if it's gotten in.
Well, this gives you some things to check at least.
 
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