Civic hesitation problem...

Buddy of mine just rebuilt (with all OEM parts!) a D16A6 with PGM-FI for his '89 Civic (including the appropriate computer and wiring harness). Got it installed, turned the key, engine turned 3 times... and fired
right up. Very nice. Idles smoooooth and quiet...
But when he gives it any gas, even just sitting in neutral, it bogs and hesitates. Hit the gas too fast, and it just sputters and dies. Do it carefully, and once it gets 1800rpm or so, it works fine. It also seems to idle a little bit rich.
Thoughts? Ideas? He's checked for error codes, but it's not giving any.
TIA
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Matt Ion wrote:

BTW, it looks real nice, he's done a lot of work cleaning up the body, detailing the interior, and cleaned and repainted all the engine parts. http://www2.moltenimage.com/civic /
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Does he have enough fuel pressure to run the fuel injection? That takes more pressure than a carbureted engine,and the fuel pump may be different for a carbureted model.
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Jim Yanik
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Jim Yanik wrote:

The old engine was a D15, if memory serves, but it definitely had PGM-FI. It runs great past 2000rpm and on up to redline, it's just that initial low-RPM push that's dropping out.
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maybe a bad throttle position sensor? Maybe it's defective at the low end,perhaps a dirty/worn resistive element.
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Jim Yanik
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it sounds like you converted from DPFI to MPFI, in which case a bit of wiring was involved
simple run down to check your wiring against
ECU pin component a1 inj 1 a3 inj 2 a5 inj 3 a7 inj 4 a15 inj resistor box
run all red/blk wires from injectors back to resistor box swap pins from c1 and c2 to b10 and b12 respectively run new wire from c1 and c2 into engine bay swap out old DPFI distributor plug to MPFI plug (matching colors) wire from c1 goes to blue/grn wire on new distributor plug wire from c2 goes to yell/grn wire on new distributor plug extend TPS plug 6" and swap outer 2 wires
sounds like you forgot to switch the TPS wires
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snipped-for-privacy@gmail.com wrote:

Both engines (the one that came out of the car, and the new one) have the same intake systems, the "PGM-FI PROGRAMMED FUEL INJECTION" throttle bodies and multipoint injectors. I'll tell him to double-check the wiring, but I don't think that'll be it.
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Matt Ion wrote:

it's likely that it is - the tps sensor rotation is opposite on the 2pfi to the 4pfi. the plug and sensors are the same but the wires are reversed as a result.
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jim beam wrote:

Except that both the previous engine and the new engine are both MPFI with identical throttle bodies...
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Matt Ion wrote:

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snipped-for-privacy@gmail.com wrote:

good thinking.
if not, check the cam timing.
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Jim Yanik wrote:

I thought of that... we haven't had a chance to check it yet, but I'll pass that on the suggestion. But wouldn't the computer be throwing error codes in that case?
Fortunately he still has the old engine, complete with intake, so there's at least a known working one there :)
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Matt Ion wrote:

it may only throw codes if there's a bad connection - like if the slider's worn on the carbon track inside the sensor. reverse wiring won't be a bad connection.

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processors to synch and get a baseline established. I don't know about the Honda Civic but I do know that the Chrysler takes a day or so to get completely normal.
DaveD
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Dave and Trudy wrote:

Yeah, don't think that's an issue in an '89 with OBD-0.
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about a timing light to see what the timing does when the throttle is opened a bit? The timing should advance a few degrees, but not jump fifteen degrees or retard a lot. (It may retard some based on the rise in MAP.) Similarly he can try adding a squirt of starting fluid into the air cleaner a second before he opens the throttle to see if that improves the response - which would point to a lean mixture on throttle opening.
Mike
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Michael Pardee wrote:

Ignition timing has already been checked, but I'll pass on the other suggestion.
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