did the Tstat in my 302 now all of a sudden it idles like ****....at idle in park it sounds like it is choking out and drops over 200 rpm and sometimes dies out, put it in reverse it dies unless you hit the skinny pedal...but it takes a couple mins to start this after firing it up

i was thinking IAC valve...replaced that and still does it at idle in park but i did not notice it in reverse as bad any way...


could this be a timing issue? when i did the T stat i had to loosen and rotate the whole distributor to get at the bolt in the t stat housing do you think rotating the dist. could knock the timing out of wack?, i tightened it back down and tried to get it close to where it was before

fuel pump sounds strong when i turn the key on

pulled the codes and got
1) 179- right side rich @ part throttle (another reason i was thinkin IAC, not getting enough air)
2) 327- DPFE circuit below min. 0.2 volt...any knowledge here i have no clue what this one is
3) 328- EVP circuit below min. 0.2 volt...think that could be the cause?

just tryin to gather some ideas here...lemme know if im on the right track

thanks guys

 

When I first saw your post I was thinking IAC too, but I guess you already proved that wasn't it.

Do you think it might be the TPS?

Why did you have to mess with the distributor to get to the T stat housing? If you did in fact change that then the timing could be off now.

I have replaced that a couple times on my truck and never had any reason to touch the distributor.

I would take care of the codes anyway though.

 

well the plug for the wiring harness was in the way of the wrench and i could not get on that pesky lower bolt any other way... all i did was loosen it and rotate it then put it back where it was and tightened it back down, i didnt think that would change the timing any?

im gonna check into the EVP and fix that up, im thinking that might be a cause for it also

wheres the TPS located again? near the pedal? i thought the TPS would throw codes if it was malfunctioning

and im thinking the EVP code and the running rich code are related and they both might be related to the idle problem i am having, because it feels like it it choking out which i would think to be air intake, and if it is that bad it might also be bad enough to cause the engine to run rich @ part throttle because it is not getting enough air

the other code for the DPFE circuit, i dont know what the DPFE circuit is so i cant even begin to fix it hahah

 

I think if I remember correctly the EVP can cause poor running conditions. Maybe someone else knows for sure.

The TPS is located on the bottom of the throttle body.

If it has been running rich for a while, your cats could be clogged.

 

yeah thats possible i was thinking about checking the O2 sensor and that should tell me, the O2 sensor could be screwed too right

 

It could be, but I wouldn't say that it necessarily is. How old is it, is it the original one?

 

In this thread, Conanski tells more about the EVP.

https://www.ford-trucks.com/forums/8...est-codes.html

 

I don't understand this one.

) 179- right side rich @ part throttle

If its a pre 96 truck and is not OBD II then it only has 1 O2 sensor, so how does it know what bank is rich?

 

I think the DPFE and the EVP serve the same purpose and you probably have only the EVP. This is what I gathered from searching here on FTE.

 

i dont know how old the HEGO is on this thing

yeah the DPFE and the EVP do the same thing from what it looks like, so the EVP is bitched so the computer throws codes for it and/or the DPFE

no clue whats telling it the right side is rich but thats what it tells me

since i changed the IAC the CEL has not been appearing nearly as often, i rarely see it now as opposed to every 10 mins at least... and it seems to go away faster, so i have to check the codes again and see cause something must have disappeared

depending on what happens tomorrow i might be parking the truck for half year at least so its not a huge deal

 

Why would you be parking it for 6 months?

 

winter coming soon...it got sketchy with the 4x4 last year and this year is supposed to be worse, plus with school right now i cant afford to insure both of them

 

That makes sense then.

 

sure does, but i wanna figure this out in case i try to sell the bitch lol...i have a good list of stuff to check out so once the 4x4 is on the road and im done spending money on it for a while i will fix up the ole 91 and sell it

 

That sounds like a good plan. Hopefully, it doesn't take too much to get the 91 working right.