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1998 Crusader 454 XLi dies after running

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Pknappe

New member
I have a 1998 Tiara 3100 with twin Crusader 454 XLi engines, fuel injected MEFI 4. The port engine will start fine when it’s cold. After running under power near idle for some time, it will die. Then it won’t start again until you wait Some time, usually the next day. I was reading that it might be oil pressure switch or maybe ignition switch. Any other ideas? Does anyone know where you can get a service manual or electrical diagram for this engine?
 
If your engine is as described, I doubt that you have the MEFI-4 ECU....more likely the MEFI-3...

On the MEFI-3 setups, the fuel pump is controlled by a relay driven by the ECU and the ECU uses the distributor's trigger pulses as an indication that the engine is running....different story on the 454XL's with the carb and the electric fuel pumps...

A scantool would likely help. The bottom line is you need to understand what's failing. FWIW, the Crusader manual for the MEFI-3's is the GM (Delphi) manual, which can be found with an internet search (wiring diagrams included). Also, the relays are known to fail so, if they are original, that may be a good place to start.
 
makomark said:
If your engine is as described, I doubt that you have the MEFI-4 ECU....more likely the MEFI-3...

On the MEFI-3 setups, the fuel pump is controlled by a relay driven by the ECU and the ECU uses the distributor's trigger pulses as an indication that the engine is running....different story on the 454XL's with the carb and the electric fuel pumps...

A scantool would likely help. The bottom line is you need to understand what's failing. FWIW, the Crusader manual for the MEFI-3's is the GM (Delphi) manual, which can be found with an internet search (wiring diagrams included). Also, the relays are known to fail so, if they are original, that may be a good place to start.
Click to expand...

Makomark, thanks for the reply. I am not sure what ECU I have. I will double check. Do you know where this relay is typically located or how I would identify it? Do you think the failure point might be the relay or the ECU?
 
In my limited experience, the ECU's are pretty tough and resilient...

I believe on the late 90's versions, the relays are mounted on a bracket in the same area as the fuses and the main breaker...

I'm thinking the relays are a good place to start...that said, without some troubleshooting, its a crap shoot....
 
makomark said:
In my limited experience, the ECU's are pretty tough and resilient...

I believe on the late 90's versions, the relays are mounted on a bracket in the same area as the fuses and the main breaker...

I'm thinking the relays are a good place to start...that said, without some troubleshooting, its a crap shoot....
Click to expand...

Sounds good. Will start there and with the oil pressure relay. Thanks Makomark.
 
makomark said:
make any progress?
Click to expand...

I finally was able to recreate the non starting situation. But first I swapped the coils and the relay near the coil from starboard to the port engine. Took it for a drive and of course if started every time. Then I was installing some flush valves and it was a hot day and the sun was shining right on the back of the engines. Went to start the port engine and it did not start. Turned over but did not start. I hooked up my fuel pressure gauge on the manifold, and when I turn the key to ignition, the fuel pump comes on for two seconds then shuts off and I saw about 30-40 psi of fuel pressure. This is normal. However, when I then crank the engine, no fuel pressure. So to me this indicates that the fuel pump is good, but one of the relays is failing when hot.

Was not able to upload pictures. I swapped the top relay by the coil but not the one lower behind the HX. I think I might have to remove the HX to access it. Could this be the relay that is causing my problems? Also am thinking about swapping the oil pressure switch by the oil pressure sender.

Any other thoughts?
 
i can't remember which relay is located where...it can't hurt to change the relay out...

The two seconds of fuel pump ON time is normal as you stated...the pressure should remain in the rail when you start to crank the engine...and it will drop until the fuel pump is turned on...
 
Pknappe said:
I finally was able to recreate the non starting situation. But first I swapped the coils and the relay near the coil from starboard to the port engine. Took it for a drive and of course if started every time. Then I was installing some flush valves and it was a hot day and the sun was shining right on the back of the engines. Went to start the port engine and it did not start. Turned over but did not start. I hooked up my fuel pressure gauge on the manifold, and when I turn the key to ignition, the fuel pump comes on for two seconds then shuts off and I saw about 30-40 psi of fuel pressure. This is normal. However, when I then crank the engine, no fuel pressure. So to me this indicates that the fuel pump is good, but one of the relays is failing when hot.

Was not able to upload pictures. I swapped the top relay by the coil but not the one lower behind the HX. I think I might have to remove the HX to access it. Could this be the relay that is causing my problems? Also am thinking about swapping the oil pressure switch by the oil pressure sender.

Any other thoughts?
Click to expand...

i think i finally solved this problem. Went to start the port engine the other day and no go. Would turn over but not start. Put on the fuel pressure gauge and when I turned on the key, would get fuel pressure for two seconds. But when i cranked the engine, no fuel pressure. Looked at MEFI manual and saw that the fuel pump is interlocked with ignition module. Decided to swap the port and starboard modules. While taking out the port module, noticed that the two wires on the internal connector fell off. They were not properly seated in the connector. Reseated the wires in the connector and port engine started right up. This was a new distributor i had just had my mechanic replace. Just goes to show that you cannot assume things are done properly. Thanks to Mako Mark for all his help.
 
Glad to help and happy you resolved the issue.

As a wise board member recently observed 'marine engines get more complicated everyday and the mechanics have a tough job keeping up'...
 
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