Won't start warm/low idle

[dbkirkp]

Hey, 

 

 

I previously posted about my newly purchased Comanche that wouldn't start in September. http://comancheclub.com/topic/51278-bought-an-mj-today-now-it-won't-start/

 

The issue is that it often won't start, especially if warm. At times I have hitched rides home to pick it up the next morning after driving it somewhere. (it isn't a DD). Since Posting I have tried several things such as 

1. Went through items 1-5 on Cruiser's list
2. installed a new CPS
3. purchased and replaced cables with Mean Lemmon's custom cables.

I installed the cables last night and it drove strong afterwards. It was slow to start this morning, but I decided to take it to work anyways and after I got it to work, it wouldn't start again. This morning the idle was lower than it was last night (~500 RPM). I have started it before by opening the throttle body all the way when warm. 

 

Things suggested previously that I haven't addressed are 

 

1. Possible leaky injectors or pressure regulator (Is there a way to test this besides buying new parts and throwing them on?) - It doesn't smell like gas
2. A shut down relay that presets the IAC (Is this the IAC sensor itself or something else?)

 

I was after seeing another thread with an idle video talking about vacuum lines that can be an issue as well, but I bought this truck to be a better mechanic. I would like clearer insights on where the vacuum issues would be, how to test and how to fix. (There was stuff about spraying starting fluid, but I don't know why you would do that and what you would be looking for). 

 

I am still perplexed on how to fix the issue. Any help will be much appreciated. 

 

 

[cruiser54]

As for injectors, it never hurts to upgrade to the Volvo 746 injectors. Can be had on ebay. 

 

Have you cleaned the throttle body and IAC yet? http://cruiser54.com/?p=60

 

Vac lines?   http://cruiser54.com/?p=121

[dbkirkp]

Thank you! I will be going through the list. I just found that the top bolt of the IAC is missing and it was kind of hanging loose. That is big. I will clean it and get a new bolt in today. 

 

On the volvo injectors ... it is any injector with 746 as the trailing numbers right? Many of the ones on ebay are used, would you be concerned at all about buying used injectors? 

[cruiser54]

The complete number is 0 280 155 746. I buy refurbished ones all the time. 

[dbkirkp]

Some fun developments have occurred. The bolt that held in the IAC on the throttle body wasn't missing, it had broken off flush under the previous owner. I have tried to drill it and back it out using a screw extractor, but my skills were not very precise (and it is a small bolt to begin with) -I ended up breaking the extractor off in the hole. 

 

I either need to find a machine shop with a drill press or head to a salvage yard and grab a new throttle body. 

 

I read several places about bored-out (60mm) renix throttle bodies. Are these worthwhile if I am getting a new throttle body anyways?

 

Last pull-a-part I went to did not have any Renix era jeeps. There has to be a renix throttle body floating around Salt Lake somewhere.

 

Any tips or suggestions?

[cruiser54]

Some fun developments have occurred. The bolt that held in the IAC on the throttle body wasn't missing, it had broken off flush under the previous owner. I have tried to drill it and back it out using a screw extractor, but my skills were not very precise (and it is a small bolt to begin with) -I ended up breaking the extractor off in the hole. 

 

I either need to find a machine shop with a drill press or head to a salvage yard and grab a new throttle body. 

 

I read several places about bored-out (60mm) renix throttle bodies. Are these worthwhile if I am getting a new throttle body anyways?

 

Last pull-a-part I went to did not have any Renix era jeeps. There has to be a renix throttle body floating around Salt Lake somewhere.

 

Any tips or suggestions?

 

At this point, a replacement would be fine.

The 60mm throttle body and giving yours as a core is not a bad idea. www.strokedjeep.com