tech question

[waynehall2290]

i just bought a 1991 beretta gt 3.1 with 132k and the guy said it has new fuel pump reg and injector harness i checked the coils and they fall within all areas on readings i got back but this thing turns over runs 5 sec dies start runs 5 sec dies sounds kinda like misfire or something runs like only 3 or 4 injectors giving any gas .....any suggestions

[3X00-Modified]

did you test/ohm out the injectors themselves?

[DTMAce]

Did you actually measure the fuel pressure at the fuel rail as well? Just because things have been replaced doesn't mean that its fixed. Sometimes you get a new bad part.

[waynehall2290]

the injectors are 14.5ish ohms and fuel pressure is 45psi drops a tad when u start it but stableizes soon after after cleaning the iac the plugs on tps and so on made sure of no vac leaks new uim gasket tested coilpacks they were within spec used the old school key to read flashes on ses light and it flashes once pauses the twice fast and repeats and the idle is now back to normal range but fluctuates between 750 and 1200 kinda like symtoms of bad iac i think could be too large of injectors cause i had short fat ones and these are newer long skinny 3100 style injectors one thing after another gotta love it

[waynehall2290]

the new injectors were 14.5ish ohms the coils were within spec on ohm test and the fuel pressure is 45 psi and slightly drops and returns to normal after about 1 or 2 sec no vacum leaks new intake gaskets cleaned the fuel rail out the new injectors are tall skinny 3100 style instead of the fat canister ones that were on it the car has 132k i checked the ses light and it blinks 1 time and after second or two 2 quick flashes and it continues this til the key is turned off it idles at 750 to 1500 now after cleaning sensors and connections but it misses like hell thinkin too much fuel causing miss fire cause the throttle is touch as hell and over 2k it evens out and dont miss what a friggin pain in the ass

[waynehall2290]

the fuel pressure is 45 psi and stays about same while starting drops a tad while firing over but comes back when engine starts i have got the idle back to normal and it still fluctuates like its the iac sensor i have checked the ohm on the injectors and they are about 14.5 ish cold the coils were not bad new plugs wires coils cleaned the injector rail iac valve map sensor and tps and done electrical check and they all were in spec maybe larger injectors idk at this point i used the key for the ses light and it flashes once pauses then two quick flashes and repeats then when you tur key on ses is right back on starting to belive it may be bad pcm it starts and at idle it jumps back and forth between 750 and 1500ish and sounds like major misfire but if you give it gas the pedal is super touchy and i have ran into the issue that it hung up and would rev to like 5k when started which pointed out the tps but when i klled the key tach stuck at whatever rpm til key was turned back over how the hell is this thing reving with closed throttle body

[ronaconda]

Injectors should be between 12 and 13 ohms.

[waynehall2290]

ok i am thinking that its stopped up return line because i went and ordered yet another set of injectors specs were right installed and started ran a little rough with miss for few seconds shut off started it up and didnt realize tb gasket was leaking small backfire and lots of fire and s#*t golden bricks got it out with minimal damage just few vacum hoses on the tb and 10 years off my life from heart attack but besides that i am courious of few things could two coils be hooked up backwards causing the rough idle cause it sounds like its outta timing but when hooded to fiming light it reads good timing .....and I was big into older j bodies and i know the later berettas had 3100 sfi and was courious how much work is involved in swapping uim and lim and fuel rail with adjustable fuel regulator off of the 31 or 3400 and swap it i know they are obd2 and all that buisness but anyway to make it work with obd1 i eventually plan on turbo and i know off the line those intakes flow circles around crap design of mpi intake any tips will be greatly appriciated

[ronaconda]

How did you read "good timing" off of the waste-spark system??? And there are no marks to verify timing...

A couple of things...if you got a backfire, i would be seriously concerned. Something is messed up pretty good. On the OBD I system, only a couple of things can mess up the timing, which is totally computer controlled. Timing is "generated" by the crank sensor. The knock sensor can also mess up your timing if you have a bad one. In my case, when my 89 did something similar to yours, my ECM was bad.

Also, the injectors shouldn't be skinny...they should be the "fat" ones. I have a set of good injectors that i can send you.

About the coils...they can't be hooked up "backwards". Spark plug wires can be installed on the wrong post, which could cause a REALLY rough idle, but only if about two of the wires were hooked up wrong. Any more than that, and it wouldn't run. Looking down on the packs, they should be 1-4, 6-3, 2-5.

If you need a new vacuum tree, i have a good one i can sell you. PM me if you are interested in the injectors and/or vacuum tree.

[d_slover]

I had similar problems intermittently over awhile....finally found out it was the crank sensor