Hesitation

CAJUNGUY1965

MEMBER
1995 CHEVROLET S-10
2.2L
2WD
MANUAL
200,000 MILES

My s10 has had a slight hesitation in it since I've had it for two years. Lately it's been getting real bad. I lose speed while driving normal. U can't go over 50mph while pulling an empty trailer. I have cleaned EGR valve real good, changed plugs and wires, changed pcv valve and hose, changed fuel pressure regulator, checked cat converter, changed purge valve, all sensors, and I'm still having same problem. I have ran Lucas fuel injection cleaner through fuel system. I stated engine then sprayed carb cleaner around intake manifold. No difference. Fuel injectors all have resistance within specified range. Black grits that look like charcoal get in one of the holes of vacuum pump. I guess it's from the purge valve. I hooked a scan tool to it that reads obd 1 systems. Scan tool gave an error. It couldn't connect to the computer of the truck. What could be going on with this?

5 Replies

HMAC300

MECHANIC
48,601 POSTS

It may be a connection problem or you have the obd1.5 not obd 1 some gm vehicles had that and are very hard to read because not to much equiptment I s around to do it. Check fuel pressure with a gauge shold be 41-47 psi key on. Auto parts rent it.

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Thursday, August 25th, 2016 AT 12:07 PM

CAJUNGUY1965

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39 POSTS

I had fuel pump pressure checked yesterday. Mechanic said it was good. I changed fuel filter today. Still no difference.

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Thursday, August 25th, 2016 AT 12:19 PM

HMAC300

MECHANIC
48,601 POSTS

You'll have ot get it scanned then it may be a bad connection, broken wire or just the scanner doesn't work on it

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Thursday, August 25th, 2016 AT 12:54 PM

CAJUNGUY1965

MEMBER
39 POSTS

How do I test the ECM on my 1995 chevy s10? I have a test light and a multi meter. I believe I may have a bad ECM. It should have either an obd 1 system or obd 1.5. I have no dash lights so I can't say if the check engine light is on or not.

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Wednesday, August 31st, 2016 AT 9:08 AM

HMAC300

MECHANIC
48,601 POSTS

You have to eliminate most things causing the problem prior to replacing ecm. A mechanic should really make this determination because you could change it and have the same problem.