I have a 97 1500 with the 5.2. It has a problem that I’m having trouble identifying. When you first start it cold it will start and then struggle to run and dies. After it dies a few times it will stay running. It then will idle very rough and then rev up. It does this over and over. If you try to give it gas it will bog and die. It seems to be running very rich. Plugs are black and it has gray to black smoke coming from the exhaust. I have checked the following and all seem to be ok. Air temp, coolant, map, tps, and vacuum is steady when it idles. The o2 sensors read about the same but for some reason my cheap scan tool will only connect when it’s not running. I have found that if I spray intake cleaner in the throttle body while increasing the throttle it will run at high rpms just fine only while spraying. Sometimes it will smooth out when it starts to warm up but hesitates when accelerating. The smoke from the exhaust is worse when accelerating.

Thanks for any help.

 

Could be a few things [&:]

Clogged cat maybe, thus why it won't idle good and it does at higher RPM.
The O2's like you said could be giving a bad reading.
Your plenum could be really bad
Blown head gaskets or worse your heards are totally shot.

How many miles?

 

Thanks for narrowing it down!!!

It has 145000 for mileage. If the o2 sensors were bad would it cause a problem on a cold start? What sensors in this system does the computer read when it’s in open loop? I check the crankcase for vacuum like the 09-05-00 spark knock/oil consumption tsb said. Not that mine is knocking or burning a lot of oil I just thought it could be a vacuum leak. It had pressure and not a vacuum. I think I will check into the heads. I really don’t want to pull the valve covers so I can do a cylinder leak down test but I think that is the next best thing to try. I did notice that the exhaust was sucking every so often when I held my hand over it. I changed the cat a few months ago but the problem then was it would idle fine but lost power when you tried to give it gas.

Well if I don’t get anymore ideas I’ll do a clt test in a few days.

 

Check out my engine in this thread:
https://dodgeforum.com/m_393897/mpage_2/tm.htm

Perhaps your fuel rail and a few injectors are clogged. I've been hemmign and hawing yanking-n-tanking the block. I'm going to "go for the gusto".

 

Tonight I went for the quick test. Did a compression test all cylinders were 120 to 130. I really wish my scan tool would connect while it’s running. Anybody know about the sensors during open loop. My guess is the computer reads the coolant temp, air temp, tps, and map sensors. All of these sensors check out ok. Why do I have such a big problem?

I’m running out of ideas. Please help I don’t want to take it to a shop.

 

Check the injectors as VWandDodge mentionned. It could also be a dirty Idle Air Control (IAC) in the throttle body but I think there's more to your problem if it bogs when you give it gas.