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upper and lower intake

d90gt

New Member
can I pick your brain? hot starting issue, brand new 19lb injectors and brand new injector harness, timing at 14, brand new 70mm tb, stock upper and lower intake with a 3/8 spacer, new cap, rotor and plugs, new wires, new TPS, new ECT, FPR set at 28 idle, starts great cold, runs great, pulls very well, drive 1/2 hr shut it off and don't want to start, turns over great, if I pull fuel pump relay hold foot to floor it starts then plug relay back in and its fine til I shut it down again, any ideas, it will not register any codes
 

broncojunkie

Active Member
Check your fpr and see if it's leaking into the vacuum hose. The diaphragm might be bad and leaking off fuel after you drive it. When you try to restart it, it's loaded up on fuel and floods out. You may need to drive it, then shut it off and immediately pull the vacuum hose off the fpr and either stand there and watch it or rig up a short piece of hose to a cup (from the vacuum nipple on the fpr). The goal is to see if gas comes out of the vacuum side (it shouldn't).

That's just a theory based on what you described. My first thought was that you could have one or more injectors leaking off.

Another thing you can check is whether or not you're getting spark when this happens. I believe the ecm detects injector pulse. If no pulse is detected, it doesn't send spark. At least, I believe that's how it works iirc. Easiest way I've found to check spark is with a timing light. You can check any or all plug wires. Comes in handy when diagnosing a miss.
 

d90gt

New Member
ok just drove 20 miles, runs great, shut off in garage then no start, plenty of blue spark from the plugs
 

broncojunkie

Active Member
Have you tested fuel pressure? I would put a gauge on it when it's not starting. If you have good pressure (30-40 psi), I would suspect the injectors aren't firing. Try a shot of starting fluid and it should start up, however, that won't tell you if it's a fuel pressure problem or injectors not firing. If your injectors aren't firing, I would suspect your tfi module. They tend to cause problems when they get hot. You can have it bench tested at most parts stores. Make sure they repeat the test a few times. If you end up buying a new one, have it tested before leaving the store.
 

broncojunkie

Active Member
I keep reading that the parts store brands are garbage, but personally, I think they're all cheap. Pretty sure they're all made in China. It's one of those parts you should probably keep a spare handy in your glove box.
 
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