1996 DT150S Overheat buzzer and light problem at low speed and idle.

[artdf175]

N2
*** has been two years
I'm still confused on what engine
you say it is a '96 "DT" model
you talk about fuel injectors not carburetors
overheat? when was the water pump replaced?
did you use just a new impeller or a full replacement kit ?
the kit is highly recommended .. replaced every year depending on use and every two years regardless of use.
and when you put the lower unit back on make sure all the gaskets are fitting correctly..
couple questions on overheating
No water out pee tube? pull the hose off the nipple on the engine and run a piece of heavy mono through the nipple
does your engine have a wash out fitting on the port side with a fitting for a garden hose to flush the engine?
if so it needs to be inspected to make sure there is no debris .. remove and inspect behind it..
there might be a high pressure relief valve in the cooling system before the water goes through the engine.
If so it needs to be checked .. could be stuck open so at low RPM not enough water gets to engine.

too much fuel? fuel float issue most of the time
make sure it is adjusted properly so it shuts off correctly when lifted..
good luck
Art

[N2 Fishing]

I pulled the high psi pump, high psi filter, injection rail, injectors, fuel pressure regulator and evaporator tank. There are no carburetors on this engine. I’d upload images but they are too big of file size for this forum.

I tried using a mighty vac vacuum hand pump on the top hose port on the regulator and it did not seem to do anything to the regulator. Now the manual says to use a hand pump to introduce high psi with a fuel psi gauge in line with a T connected to the fuel inlet port on the regulator and it should release psi at about 34 psi or something like that. I need to get some 5/16” fuel hose tomorrow to get the fuel psi gauge set up to do the proper test.

I did check the injectors with an Ohm meter and three of them read 13.6 Ohm and three of them read 13.7 Ohm so electrically they are good but still have not tested for clicking on and off with power or to see if they leak.

Water pump was just replaced again this past week with a impeller, key and bottom SS plate with new gasket. Did that to rule out bad pump after sitting for a year.

Here is me after a few drinks trying to explain things on this engine but I was not thinking clearly when I recorded that video for obvious reason. You can see all the injection stuff in this video to put that carburetor question to rest. I really don’t suggest watching the whole video. It drags on while I try to explain things coherently and failed.

https://m.youtube.com/watch?time_con...ture=emb_title

[artdf175]

Well with the water pump - that should rule out not enough water..
once you get it back in the water verify that you get a good stream out the pee tube..
I may have missed it but have you checked or replaced the thermostat ?

I can't find on this site parts listing your engine .. all the 1996 150's are carburetor models..
usually fuel issues like you mention deal with a float valve not closing .. the VSP then dumps excess fuel
don't be afraid of the low pressure pump
pretty simple design .. if you are getting fuel to the high pressure pump - the low pressure is doing its job
you mention flooding issue.. the only thing I can think of is either the fuel injectors are worn out- not closing completely or maybe fouled so they let fuel leak..
Have you tried a good dose of something like Seafoam? or a fuel injector fuel additive?

don't recall now but were you having problems at WOT?
Art

[N2 Fishing]

WOT does not cause overheat issues. Typically it happens with lower RPMs under a load let’s say 3000 RPM and less. This is one reason I want to do the oil flow test at 1500 RPMthe the oil pump valve fully open and fully closed for the durations of time of 5 min fully open max position and 2 minute in the minimum position. I need to get some type of tube with markings to measure the flow rates.

This is the BASS engine. I just tried googling it and not finding much info on it. It might be a newer than 96 but I was informed based on the serial plate numbers that it was a ‘96 BASS. I’ll try to remember to snap and upload a pic of the serial tag. Maybe you will be able to decipher the year based on the numbers on that plate.

I put new T-Stats in it a couple years ago even though the older ones were still good. I did it as a way to know they were not failing from being overheated too many times.

When I get it put back together with any needed new replacement parts “ hopefully they are still available “ I will put the lower unit in a bin full of fresh running water instead of using rectangle water dogs.

I have a theory that the fuel pressure regulator is stuck closed and thus is causing fuel to leak out of the injectors more than normal. I will report what I find later today after getting some fuel line for diagnostic purposes.

[N2 Fishing]

WOT does not cause overheat issues. Typically it happens with lower RPMs under a load let’s say 3000 RPM and less. This is one reason I want to do the oil flow test at 1500 RPMthe the oil pump valve fully open and fully closed for the durations of time of 5 min fully open max position and 2 minute in the minimum position. I need to get some type of tube with markings to measure the flow rates.

This is the BASS engine. I just tried googling it and not finding much info on it. It might be a newer than 96 but I was informed based on the serial plate numbers that it was a ‘96 BASS. I’ll try to remember to snap and upload a pic of the serial tag. Maybe you will be able to decipher the year based on the numbers on that plate.

I put new T-Stats in it a couple years ago even though the older ones were still good. I did it as a way to know they were not failing from being overheated too many times.

When I get it put back together with any needed new replacement parts “ hopefully they are still available “ I will put the lower unit in a bin full of fresh running water instead of using rectangle water dogs.

I have a theory that the fuel pressure regulator is stuck closed and thus is causing fuel to leak out of the injectors more than normal. I will report what I find later today after getting some fuel line for diagnostic purposes.

[N2 Fishing]

I used a fuel pressure guage with an air compressor and air regulated just over the service linit of the fuel pressure regulator and it releases pressure between 37 & 38 PSI.

According to the service manual it is with in spec. Fuel pressure regulator holds vacuum in the vacuum port as well and releases pressure lower at about 30 to 35 psi when psi is applied to the inlet port and vacuum is applied to the vacuum port I'm going to assume the regulator is good unless it has an intermittent sticking issue.

Next I need to fabricate a couple of brackets to hold the injectors onto the fuel rail so I can test them with no power but under pressure then with power under spressure to see the spray pattern.

Regulator service limits 34.1 to 38.4 psi

[N2 Fishing]

Ok I was looking at a parts PDF and while studying the lower unit/water pump I noticed the gasket is supose to go between the lower unit and the flat stailess steel plate. I've been putting it between the plate and pump housing. Has me wondering if this could be part of the problem with overheating?


My service manual does not specify how or where to installithis pump gasket.

[Murray]

Not from your engine but you may be on to something
IMG_6839.jpeg

[N2 Fishing]

That looks similar but the pump housing for my engine is metal with no groove around the surface for a O-ring type seal. This is what made me think the seal went between the under panel #3 and the housing illustrated in your diagram up there.

Thank you.

[artdf175]

I finally found the parts list
N2 the gasket does go between the lower unit and the "panel, pump under"
the impeller inside - should mate with that panel so water doesn't get between the two, and then the housing
placing the gasket between the panel and housing would have the effect of too much space and the pump would loose pressure
the schematic is correct in the placement of the parts

Art

One other thought relating to your video - you were questioning some fittings maybe missing something
I am thinking the service manual usually has pages describing routing of water hoses, wiring and such

[N2 Fishing]

artdf175 I have not been able to find several things pertaining to my specific engine while looking in the manual I have on hand including the purpose of those nipples/ports near the injectors that look like hoses are missing.

I made a video showing what I’m dealing with regarding the manual I have on hand.

https://m.youtube.com/watch?v=cFts2B1is74

[N2 Fishing]

Been thinking of a way to test the low psi fuel pumps for a leaking diaphragm with out dissecting them and thought about the following.

I should be able to remove the pumps from the engine. Then plug off the output side fuel tube and prime fuel into the pump at the input side using a primer bulb to see if fuel leaks out of the pulsation/vacuum/compression port where it plugs into the engine to make the pumps work with out leaks

If either pump leaks from the back side pulsation port then I know the pump needs to be rebuilt/replaced. Looks like there might be some check valves inside of the low psi pumps as well but the pump brake down in my manual does not show this.

I was watching a video of a guy dissecting the low psi pumps for an ‘87 DT150 and it made me think of how to check the pumps for leaks through the pulsation port on the back.

This is the video: warning long slow boring video. You can fast forward to the pump dissection. At about the 14:20 minute mark he shows check valves in the pumps but does not go into details to show if they are replaceable or not.

https://m.youtube.com/watch?v=ZvF2v1...UwIGZsb29kaW5n

[N2 Fishing]

I have definitely been installing the gasket to the water pump incorrectly.

This video shows correct gasket/seal placement. Not the same horse power engine but pretty much identical pump removal and installation procedure for the DT series engines.

https://m.youtube.com/watch?v=gaFkGbC8bhY&t=307s

[N2 Fishing]

Ok I just used a 9v battery to test for injectors clicking. They all click but don't have the same sound when they click.

Here is the serial Tag that will give all the engine details.

Model:
DT150S

Serial #:
15002 - 651116

[N2 Fishing]

Ok checked the VST and it was very clean inside. The float levels was and is right where it is suppose to be. The needle looks good too and I’m not able to blow air with my mouth past the float when it’s closing the needle to the seat.

I’m seeing parts of my engine resembles the diagrams of the DT200 in the R section of the manual, like the float and VST set up and the Air tubes to the block.

I can’t believe Suzuki does not have literature related specifically to and only to this specific model DT150S to eliminate any confusion.