Have you checked fuel pressure? Checked fuel spray pattern?

 

IF the injectors spray properly , their o ring seals are not leaking , or the body has no cracks leaking fuel then the efi is responding TO the inputs from the sensors , mass air flow , t/b temp sensor , or o-2 sensor . use the blink code retrieval method and a YEAR CORRECT code list and see if the pcm will "tell" you whats wrong . a bad engine thermostat allowing it to run TOO cold can have an effect as well ... pcm may tell you that in blink codes , may ....

 

I changed the injectors because of a bad spray pattern/leaking o-rings and running rough. The TBI had crud in it I took it apart, and cleaned it, and put new gaskets and injectors in it. The pattern is spraying, no big drips now, but it does not look like a fine spray./mist at idle. It has a new fuel pump and filter, but I will check the pressure. What should the pressure be at the TBI? I will check the temp when it's warmed up, I put in a 195 degree thermostat when I put it together. The temp gauge shows it running about 1/3 of the way up from cold, but these gauges are notoriously inaccurate. I will check with a real gauge in the radiator when it is warmed up.

 

15 psi +/- 1 I think. Do the code sequence check. It can have a stored code without a check engine light. No sure if you meant no you had light or if you did an active check.

 

either IAT or temp sensor , you need to pull CODES , any chance you can get a SnapOn MT2500 scanner and get some LIVE data

 

agreed and yes 14 plus psi fuel pressure for a throttle body ( 2 injectors ) if the fuel pressure is around 14 -15 then check the mentioned sensors . pull codes . key on /off on/ off on watch count flashing dash .

 

Pulling the air pump and catalytic wass a bad idea. There is no point to removing the catalytic converter omn a fuel injected vehicle. All that will do is make the truck pollute more.

Removing the smog pump is also a bad idea. It has zero negative effect on the engine and, in fact, helps clean up the air and make the catalytic converter last longer. Also, and probably part of your problem, the air pump injects air into your exhaust stream. The computer takes the fresh air injected by the air pump into consideration in determining the fuel mixture. If the air pump is removed the mixture will be off.

Could be the EFI computer has croaked. It is 31 years old, after all.

 

can agree with this. I removed my cat, just to be an obnoxious dick since my RC is my fun vehicle and the smell is a bit strong. I did it knowing the outcome.

 

I checked for codes, there are none stored. As for the cat and air pump, it was off when the 318 was in, and didn't make any difference, and it was not running rich. I will check the fuel pressure this weekend and look at the sensors.

 

that CANT be true as you should get at least the TWO codes that everyone gets , codes 12 and code 55 / if you dont get them either your do'ing it wrong or something else is wrong

 

DODGE CODES PRE-95

The 1980s-1990s Chrysler vehicals . Start with the ignition off. Within five seconds, switch the key on, off, on, off, on. (On is not start!) The "check engine" light will flash. Count the flashes Each code is a two digit code, so a (for example) 23 would be FLASH FLASH (pause) FLASH FLASH...

www.ramchargercentral.com

 

other wise you would need either a FSM [ Factory Service Manual which every dodge truck owner should have ] or you gonna need a multimeter and ALL the specs on the sensors from a FSM

 

Fuel pressure was 14-15 pounds, pump and regulator seems to be working ok. The water temp read 185 degrees measured with a mechanical gauge measured at the top of the radiator, it did not vary at all. I don't think there are any vacuum leaks, vacuum heal a very steady 17 pounds at idle hot. I did a compression and leakdown test on it, 300 miles since rebuld, 135-140 per cylinder hot, leakdown was 2-3 pounds across all cylinders at 100 pounds test. The only thing that I found was the water temp sensor seems to have one prong, I believe the black lead which is ground, and I had a hard time getting a reading from the other prong. Is this the source for the temp gauge on the dash? It think it is reading low. The needle used to sit just left of straight up, and it is reading just past the second line on the left. I will probably replace it, it's 10 bucks.

 

whats the IAT read [ intake air temp] and whats the Oxygen sensor do'in , how about the MAP sensor = this is where you need the scanner because all three control the fuel

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there are 2 water temp units on the intake , the one that works with the dash gauge is a single wire unit called a sender ,its ONLY function is to operate the gauge on the dash , the one that works with the engine computer has 2 wires and is called a sensor . both are located near the thermostat / upper radiator hose screwed into the intake manifolds water jacket . Water temp sensor out of range will cause a choke like overfuel if one way and a lean start if the other way . The sensors dodgeboys points out have a greater effect on the engines fuel if they are not within proper range . The single "prong" or single wire , one you speak of , the wire is power from the dash gauge , the sender gives that wire an "amount" of ground according to the water's temp and does not effect the engine controller( pcm)

 

sensor wiring




diagram expired

 

I replaced the temp sensor for the computer. Truck seems to be doing better. Is there a way to tell if the computer is running in open or closed mode? Without a specialized computer reader?

 

yup a $200 dollar WIDE band oxygen sensor and a $400 dollar multimeter and install an 02 bung in the exhaust / other wise most shops charge $50 bucks to throw the scanner on it

NOTE / you might wanna either clean or change your oxygen sensor