Problem with Tohatsu 90 TLDI

[flatsguide]

I have a 2003 Tohatsu TLDI. I have an intermitant problem when starting. The Fuel feed pump makes a loud humming noise when it is acting up. I have cleaned out the filters. FFP housing and basicaly the entire fuel system. So I bought a new Fuel feed pump for 400 bucks and replaced the high pressure filter. Took it out today and same prob. It will eventualy go when the pump stops humming. I took it to the mechanic and he too has no idea what it could be. The computer is showing no errors either. PLEASE HELP>>>>

 

[flatsguide]

Re: Problem with Tohatsu 90 TLDI

Also it runs fine once I get it going and seems to act up after I make a long run...

 

[pvanv]

Re: Problem with Tohatsu 90 TLDI

Did you run the codes out, and reset the ECU?

 

[TOHATSU GURU]

Re: Problem with Tohatsu 90 TLDI

What is the serial number of the engine?

 

[flatsguide]

Re: Problem with Tohatsu 90 TLDI

I have ran the codes and cleared them. About twenty things came up. Pretty sure Tohatsu mechanic had never cleared them. The only one that has come up in past 20 times running sense clearing is low battery voltage. But battery tests fine and runs at 14 volts when running. I was wrong too it is a 2004. Serial number is 013137XD.

 

[flatsguide]

Re: Problem with Tohatsu 90 TLDI

Sorry I thought I put this info down. It is a MD90B. Today I cleaned out the fuel regulator. It looked good. I also cleaned the air regulator. It had a ton of thick foam packed in it. I got it all out. I also took High pressure input and let the fuel pump run a few times to flush anything out.
When the fuel pump decides to humm it does it when I turn the key half way. I know at that point it is not going to want to start or stay idling. Something tells me the problem is still there and it wasnt the air regulator at all.

 

[TOHATSU GURU]

Re: Problem with Tohatsu 90 TLDI

What is the battery size in CCA

 

[flatsguide]

Re: Problem with Tohatsu 90 TLDI

MCA is 1000. It does not have CCA on the battery. I ran this battery 6 months last year, no prob. I ran it 2 of 4 months this year no prob. The FFP problem has been happening last 2 months. I cleared the codes again and am getting no codes back. Thanks for your time and help so far!!!!!!!!!!!!!!!!!!!

 

[flatsguide]

Re: Problem with Tohatsu 90 TLDI

Problem still there. Is it normal to have thick foam in the air regulator?

 

[flatsguide]

Re: Problem with Tohatsu 90 TLDI

The problem held my clients and I up about 20 min. today. Just did it the one time and finnaly started. I am CLUELESS what it could be? Any more ideas anybody??????

 

[ziemann]

Re: Problem with Tohatsu 90 TLDI

I am going to give you a bump back up to the top- hopefully someone will see it and have some ideas. This is an odd problem...

 

[flatsguide]

Re: Problem with Tohatsu 90 TLDI

I am going to give you a bump back up to the top- hopefully someone will see it and have some ideas. This is an odd problem...

Thankyou!! I need all the help I can get on this one..

 

[pvanv]

Re: Problem with Tohatsu 90 TLDI

I have ran the codes and cleared them. About twenty things came up. Pretty sure Tohatsu mechanic had never cleared them. The only one that has come up in past 20 times running sense clearing is low battery voltage. But battery tests fine and runs at 14 volts when running. I was wrong too it is a 2004. Serial number is 013137XD.

Model and serial is everything for servicing a Tohatsu/Nissan OB. Year means nothing. What 20 codes were stored? Have you followed the procedures in the Factory service manual to diagnose the problem?

Elvin is probably on the right track with the battery question. If the MCA of the battery is 1000, I would expect the CCA to be less, so you should consider trying a newer, bigger battery -- at least for testing. Tohatsu requires 1000 CCA on the TLDI motors. No, the starter does not pull a ton of amps, but during cranking, the voltage drop must be kept to a minimum so that the ECU does not have problems. The CCA requirement becomes more evident as the battery, cables and connectors get a little older, and extra resistance under load starts to show up.

 

[flatsguide]

Re: Problem with Tohatsu 90 TLDI

When the fuel feed pump humms it does it when I turn the key switch to activate the pump. I dont even bother turning the engine over when it does the noise. I know it wont start... I will look into a bigger battery... The codes where battery codes and fuel feed pump codes and fuel injector codes.... So I reset the IPS and they have not came up sense.... Thanks for the info I pray it works because I am at a loss.

 

[pvanv]

Re: Problem with Tohatsu 90 TLDI

If you haven't already done so, I would also verify all wiring connections, paying special attention to ground wires.

 

[flatsguide]

Re: Problem with Tohatsu 90 TLDI

I did go thru all the wiring. I also put gel in all the connectors just to make sure. Today I had a trip and it did it once. I pumped the bulb and noticed it was solid but didnt have gas in it? Pumped it till the bulb got full. Could it be the pick up fuel pump? I noticed too the FFP housing was hot...

 

[pvanv]

Re: Problem with Tohatsu 90 TLDI

If there is air in the fuel line, the FFP will continue to run until it gets gas pressure, so yes... check out the fuel system. Everything from tank pickup to the FFP. Pay particular attention to the primer/hose. One bad o-ring can allow air to enter instead of fuel. Keep in mind that the primer/hose is under suction when the motor is running (unless the tank is above the motor), so even a minor leak will let air in.

 

[TOHATSU GURU]

Re: Problem with Tohatsu 90 TLDI

I meant to do a service review on your engine earlier this week, but got tied up at a boat show. I'll look into it on Monday.

 

[flatsguide]

Re: Problem with Tohatsu 90 TLDI

Thankyou SOOOOO much guys. Looked at the gas lines and o-rings and all looks good to me.

 

[ziemann]

Re: Problem with Tohatsu 90 TLDI

Could it be as simple as a bad pickup in the fuel tank?