Hard start cold question - injector spray?

[tretter7]

Hey guys. I've been fighting a hard start problem, only when the engine is cold. Lately the motor seems to be running a bit rough at low speeds too, an occasional spit and pop can be heard. The engine is an Indmar 5.7 TBI from a 2003 SSV. I'm wondering if the injectors could be the culprit? I've replaced the IAC, TPS, and temperature sensor in the past couple years while troubleshooting other problems. Here's a link to a video of the boat starting and the injector spray pattern. What do you guys think?

https://goo.gl/photos/gxjz2sa572in5iA28

[SquamInboards]

Does this engine have coil packs or a traditional distributor? Are you sure this is a fuel issue and not a spark issue?

[michael hunter]

Indmar had a lot of fuel pump issues I would start there.

[tretter7]

I changed the distributor cap and rotor over the weekend and it didn't help. I'll go grab my fuel pressure tester this week and see what I've got. I'm looking for 30PSI, correct?

[lively]

Doesn't take much to keep TBI running , spray looks good , if suspect can you spray with starting fluid and it will fire right up ? Sounds like spark . Get a noid light or check plugs to se what color they are to see what your missing . Fuel is easy to diag with propane torch just use the gas to troubleshoot and then check your spark .


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[SquamInboards]

Now I see the video, clearly showing a standard distributor, oops.

Still sounds spark-related, though, especially where it's more of a cold-start and low-idle issue.

[tretter7]

Hmm... so I'm not an expert on spark related issues. Lively, what do you mean by diagnosing fuel with a propane torch?

Plugs were replaced last summer but I've never done the spark plug wires. If they pass a visual inspection, is there any reason to suspect them? There isn't that much in this motor that could affect spark, is there?

[tretter7]

Took me FOREVER to finally figure out this hard starting issue. In the end, it took a mechanic to help me diagnose it. Culprit was the ignition coil. Changed it out and the boat runs better than it has in YEARS. I didn't know coils could get 'weak'. I thought they either worked or they didn't.

Just wanted to post the resolution to the problem in case someone else runs across this thread while googling.

[chris young]

Good to hear it's fixed! It's hard to believe what t difference a weak spark can make. I used the second contacts on the starter solenoid to bypass ballast resistor on start and the boat went from very hard to start to practically a bump of the key. (Carburated 351 PCM). To your question, plug wires can absolutely go bad over time and just because you can't see a problem doesn't mean there isn't one.