Calling all 3.4L DOHC GURU'S Engine will not run right

[RUNDLC]

OK Guys Here goes, I swapped a 3.4L DOHC into my lambo project. Engine is a 94 with a 91-93 ECM, 5 speed getrag tranny. The engine is a crate motor, no miles. Once I made sure the oil pressure was up (40-45lbs) I tried starting her up, when she finally fired it ran like crap!! It seems as though the timing is off??

The engine misfires it's only run for about 3-4 minutes, but didn't run right at all.

 

Checked the spark-GOOD

Checked the fuel pressure-GOOD

Checked the crank sensor-GOOD

Checked the injectors-they are firing

Changed the ecm-NO difference

Triple checked the spark plug wires

Checked the coils-GOOD

ICM-GOOD

Checked the marks on the cams-MARKS LINE UP

 

This just makes NO SENSE!!

 

What am I missing here?? Any constructive help needed!

 

 

 

RUNDLC

 

[slick]

The marks on the cams mean absolutely nothing. I'd strongly consider redoing the timing.

[RUNDLC]

Yeah we were thinking that, but would GM send a crate motor out without timing the cams??

[ManicMechanic]

Yes.

[joey b]

first off, when one set of cam flats is up, the opposing bank should be 180* different. This is a common mistake that many people make when changing the belt. I would check that first. You can check the position of the cam flats by removing the cam carrier cover.

[RUNDLC]

Well thanks for the advice! I guess we will at least verify that the cams are set right. I need tools though, who sells the correct stuff to set them?

 

 

RUNDLC

[Psych0matt]

I can almost guarantee it's timing. I did mine fine when i was just changing a belt, but after i swapped the engine, but kept the 94 cams and intake, i timed it probably 6 or 7 times in about a month and a half span, and finally had to take it in to be timed right, something was just off and wouldn't line up right, even though the marks were all perfect

[TURBOLUMINA]

I could be wrong here, but i am fairly sure that the first year for a MAF car was 94. Therefore, if you have a 91-93 ecm hooked into a 94 harness, the ecm is seeing a MAF signal instead of a MAP signal. This would cause some problems. Does your engine have a MAF or a MAP sensor?

[RUNDLC]

I have a map, the harness is based on the 91-93 manual. We finally did get it to start, it's running rough but at least it's a start. I am going to reroute the crank sensor wires and shorten them some. We are thinking it may be getting some interference from other sources which may be causing it to jump time a little.

 

 

RUNDLc

[RUNDLC]

Well Finally some very good news to report, the thing is finally running like it should less a code 35 that it threw tody. Turns out that the crank sensor wires needed to be reversed, one of the guys on PFF had the same issue and told to please try it before doing anything else so I did a bam it fired right up.

 

This is a nice new years present!!

 

 

RUNDLC