88 2.3l timing issue

[xlt88ranger]

My truck has been bored .040 over and the timing for the truck to run with the standard can and rocker arms was 25 degrees. I recently converted my truck over to roller and the truck will start and run fine up to 2000 rpms and then acts like it is trying to reverse fire a piston. Anybody have an idea what could be the problem and how to fix it. Thanks!

 

[tomw]

If your truck has a distributor, the timing must be set with the jumper removed. You might have the timing off. The standard, un-computer modified, base timing is 10BTDC, jumper removed. The jumper is in a plug hanging out of the wire harness from the drivers side inner fender to the engine.
If you get it wrong, you'll be top end limited, or won't have any power until you get the revs above 2500 rpm.
tom

 

[Mark_88]

Yes, the spout connector needs to be jumpered to set timing...sounds like it is not advancing the spark properly...

Are you using the original setup for fuel injection or did you change that out for a carburetor? I know most people would not go that route but just thought I'd ask before we get any further...

 

[xlt88ranger]

I kept the fuel injection. I made a rookie mistake of not checking the firing order of the new cam. Instead of the standard 1-3-4-2 firing order it is 1-2-4-3. My mistake!

 

[Mark_88]

Cool...I did that a few times...makes for interesting troubleshooting...

 

[zekew64]

Just so you know, on pre-'91 setups with electronic ignition, the plug wires are sequentially numbered on each coil, going counterclockwise. Find #1, the rest is cake.

I found this out in my own quest to figure out my firing order.

 

[xlt88ranger]

Yeah I have no idea what is wrong with this thing thought that would fix the problem now it pops and runs like crap. I'm out of ideas on this thing.

 

[Mark_88]

Popping and running like carp still could mean timing issues. I know the valve timing determines TDC phase (so to speak) so all you need to do is ensure that the engine is on the compression stroke...then set everything to zero on the crank indicator, align the oil pump sprocket and then the cam to the marks...

Are you missing any markers that might throw timing off a bit?

With the distributor you can fine tune timing if you haven't already tried that...but it would be much more fine tuning than eliminating rough running and popping...

Popping is firing out of sequence...so check that wiring once more...and hang in there...when I first did timing belt on my 2.0 it took me three or four tries...and even years later doing it again took a few shots...just one tooth out and it runs like carp...