1987 R10 w/ Factory TBI Stumbles and Dies when Hot

[jrblanke]

1987 R10 w/ factory TBI stumbles when hot.

Question regarding a friend’s 1987 R10 long bed. The truck cold starts fine, but when it gets hot it is difficult to start. Once its hot it takes longer to fire, and when it does fire, it will die when he shifts it into drive.

Is this a common problem? Is there anything in particular to look for when doing a tune up? As said on the title, the truck has factory fuel injection and is completely stock.

[xs-style]

Replace the fuel filter. If your doing a tune up anyway, 6 bucks is a small price to pay for an item that's often forgotten or plain old skipped over. Also go to your local harbor freight and get a fuel pressure tester , a vacuum tester, and a multimeter. They run about 15 bucks each. Fuel delivery problems or vacuum issues are normally the cause of what your describing.

[Tiger Joe]

x2 start with fuel filter. I had similar issues with my 87 tbi- stumbling at idle and die when shifting into park, and a new fuel filter fixed it

[Desert1957]

Originally Posted by tiger joe

x2 start with fuel filter. I had similar issues with my 87 tbi- stumbling at idle and die when shifting into park, and a new fuel filter fixed it

x3

[jrblanke]

The fuel filter was recently replaced. It starts right up idles fine when cold but stumbles and is difficult to start when hot. Once it’s started it has plenty of power throughout the rpm range.
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[xs-style]

Pull the starter and have it tested. They can heat soak if not properly shielded, especially with age. Your local AutoZone can do it. Have them run the test a few times so it gets warm. On the same trip you could take the ignition control module. It can be tested as well. Same deal, ask them to run the test a few times so it gets warm.

[jrblanke]

Originally Posted by xs-style

Pull the starter and have it tested. They can heat soak if not properly shielded, especially with age. Your local AutoZone can do it. Have them run the test a few times so it gets warm. On the same trip you could take the ignition control module. It can be tested as well. Same deal, ask them to run the test a few times so it gets warm.

I am not familiar with the term heat soak, but the truck isn't having a hard time turning over. It seems like either a spark or fuel issue. I assume that it is a fuel issue since the truck runs fine. Is there a fuel check valve or something that is malfunctioning when the engine is hot?

[xs-style]

There's no fuel check valve or anything. But like I say, have that ignition control module tested. A wells tester puts it under normal operating load. If it gets hot and fails the wells test, you'll know that component is bad.

[cadillac_al]

I'd say if there are no codes it must be a fuel pump going bad or the fuel filter.

[v30crewcab]

sounds like the coil is messing up when it gets warm. other possibility is the distributor is worn. we had one that would randomly shut off when running. distributor fixed it.

[D13]

Classic symptom of coil or weak ignition module. Check for good hot spark while cranking.

[jrblanke]

Thanks guys, Sounds like we have some things to check. I appreciate the help! I'll report back once we get a chance to work on it some more.

[blakerj10]

My blazer was doing something similar. Died on me about 5 or 6 times in about 6 months. Would restart after cooling off a bit. Then it died and would not restart. Took ignition module out of distributor (youtube video out there). Autozone can test them. Popped new one in and runs better than anytime since I have had it.