Jump to content

Massimo msu 400efi intermittent problem

Recommended Posts

So I have a msu400 efi. Ran fine, pulled it into the shop to do my typical routine maintenance, cleaned air filter, change oil, etc. 

So now it won't run right. Starts and idles, stumbles on acceleration. If I baby it I can get it moving, but dies after a few hundred feet and then is hard to start. Will start back and idle just fine as long as you don't rev it up. 

So what I've done so far.

Verified fuel pressure at injector, never losing it. (54psi)

replaced fuel injector. Verified spark right after dying (sparking like hell)

checked valves. ( Proper clearance) replaced map sensor, idle control sensor, and tps. (No change)

disconnected negative battery cable for 20mins (no change)

checked exhaust, (free and clear) 

Checked air filter again and intake tube (all good)

After it dies or if I just let it sit before starting it, it throws code 113, which I've seen is IAT voltage too high or open circuit. I have a 4 wire sensor and am not sure the wiring back to the ecm nor can find a good diagram. Not even sure if this is a problem or just a code it would throw if it is just not running. 

Any help would be appreciated 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...