travisamorgan

Recently I replaced my thermostat and did head gaskets. Since then ive had nothing but problems.

When I start my truck it doesnt idle around 1500 like it should when its cold (its around 40 degrees here and been colder and a lil warmer). It idles really low like under 500 rpm. I warmed it up driving around and then adjusted the idle to around 800-900. It stayed at that idle while driving around again. Once I stopped and turned off the truck and went inside to a store and came out 20 minutes later I started the truck and it didnt do any warmup idle (it was at about 1/4 of the gauge) and it was idling at below 500 again. I drove it home (15 minutes in 45 mph) and it was warmed up but idle was still at below 500 rpm. Its like the computer doesnt care what the idle setting is it does whatever it wants.

I have played with idle over the last few days and have had this problem constantly. At one point it was idling so low it would stall but I think that was from my exhaust leak by the header where it comes down to the o2 sensor and it is reading high oxygen so its richening the mixture too much and its causing it to flood out. But since then im pretty sure I got it sealed up pretty decently.

I know at idle it sounds like a miss and its running rough but I cant tell if its a actual miss or rough running from idling so low. I cant here the miss driving since the exhaust ( magnaflow) covers it up and the road noise and the noise from the cooling fan. Every now and then I here a miss at random rpm in neutral that sounds like a thumping sound like a rubber hammer hitting a concrete block. I cant make it do it and it doesn't happen at a certain interval or anything.

Im more worried about my idle so I can drive in traffic and stop and go easier without having to play with the idle every stop. Im planning a 3.4 swap asap in a few months or sooner so just need it to make it til then.

Its a 5 speed with no a/c and flamethrower injector (orange) and magnaflow cat and muffler and 2.25in pipe and egr and pair valve removal (egr was junk and doesnt do anything at idle anyway) and there are sealed on the header. No vacuum leaks that are obvious and will check for them asap but wanted to know if any other problems could cause it.

Thanks Travis

travisamorgan

Anyone know? Any advice?

ksti

Could be a number of things conflicting since HG install along with mods and removal's.
Start with the easy stuff.
See if there is any codes stored to start with.

travisamorgan

It ran fine before the head gaskets blew and only change since before was the flamethrower injectors?

The check engine light never came on since ive done the head gaskets.

If I unplugged the tps sensor would the computer go back to stock run settings so ot wouldnt change it and it wouldnt look at the o2 sensor and throttle position?

Could the computer just not have adjusted to the new injectors yet since the compter is extremely slow? Just need more starts to running temps needed??

ksti

The check engine doesn't necessarily need to come on to have codes stored.

travisamorgan

True I guess it could have old codes. Ill look. I did reset the computer already to try to see if that helped. I unplugged it fron the battery for a while.

Mr. Magoo

OP did you ever find out what the problem was? Mine is doing the same thing.